for Journals by Title or ISSN
for Articles by Keywords
help

Publisher: Elsevier   (Total: 3041 journals)

 A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

The end of the list has been reached or no journals were found for your choice.
Journal Cover Plant Physiology and Biochemistry
  [SJR: 1.167]   [H-I: 84]   [7 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0981-9428
   Published by Elsevier Homepage  [3041 journals]
  • Comparison of silicon nanoparticles and silicate treatments in fenugreek
    • Authors: Sanam Nazaralian; Ahmad Majd; Saeed Irian; Farzaneh Najafi; Farrokh Ghahremaninejad; Tommy Landberg; Maria Greger
      Pages: 25 - 33
      Abstract: Publication date: June 2017
      Source:Plant Physiology and Biochemistry, Volume 115
      Author(s): Sanam Nazaralian, Ahmad Majd, Saeed Irian, Farzaneh Najafi, Farrokh Ghahremaninejad, Tommy Landberg, Maria Greger
      Silicon (Si) fertilization improves crop cultivation and is commonly added in the form of soluble silicates. However, most natural plant-available Si originates from plant formed amorphous SiO2 particles, phytoliths, similar to SiO2-nanoparticles (SiNP). In this work we, therefore, compared the effect by sodium silicate and that of SiNP on Si accumulation, activity of antioxidative stress enzymes catalase, peroxidase, superoxide dismutase, lignification of xylem cell walls and activity of phenylalanine ammonia-lyase (PAL) as well as expression of genes for the putative silicon transporter (PST), defensive (Tfgd 1) and phosphoenolpyruvate carboxykinase (PEPCK) and protein in fenugreek (Trigonella foenum-graecum L.) grown in hydroponics. The results showed that Si was taken up from both silicate and SiNP treatments and increasing sodium silicate addition increased the translocation of Si to the shoot, while this was not shown with increasing SiNP addition. The silicon transporter PST was upregulated at a greater level when sodium silicate was added compared with SiNP addition. There were no differences in effects between sodium silicate and SiNP treatments on the other parameters measured. Both treatments increased the uptake and accumulation of Si, xylem cell wall lignification, cell wall thickness, PAL activity and protein concentration in seedlings, while there was no effect on antioxidative enzyme activity. Tfgd 1 expression was strongly downregulated in leaves at Si addition. The similarity in effects by silicate and SiNP would be due to that SiNP releases silicate, which may be taken up, shown by a decrease in SiNP particle size with time in the medium.

      PubDate: 2017-03-17T10:05:08Z
      DOI: 10.1016/j.plaphy.2017.03.009
      Issue No: Vol. 115 (2017)
       
  • Early response of wheat antioxidant system with special reference to
           Fusarium head blight stress
    • Authors: Valentina Spanic; Marija Viljevac Vuletic; Ivan Abicic; Tihana Marcek
      Pages: 34 - 43
      Abstract: Publication date: Available online 14 March 2017
      Source:Plant Physiology and Biochemistry
      Author(s): Valentina Spanic, Marija Viljevac Vuletic, Ivan Abicic, Tihana Marcek
      Fusarium head blight (FHB) is a destructive fungal disease of wheat (Triticum aestivum L.) that causes significant grain yield losses and end-use quality reduction associated with contamination by the mycotoxin deoxynivalenol (DON). Three winter wheat varieties (‘Vulkan’, ‘Kraljica’ and ‘Golubica’) were screened for FHB resistance using artificial inoculation technique under field conditions. The aim of this study was to examine a relationship between FHB resistance and the effectiveness of enzyme antioxidant system of wheat varieties under different sampling times (3, 15, 24, 48, 96, 120 and 336 hai). In the time-course experiments FHB-resistant variety ‘Vulkan’ showed rapid induction of ascorbate peroxidase (APX) and polyphenol oxidase (PPO) activity in the early stages after infection (3 hai) and it seems that in ‘Vulkan’ FHB-resistance is associated with antioxidative enzymes activity. Moderately FHB resistant variety ‘Kraljica’ showed the higher guaiacol peroxidase (POD) activity and higher H2O2 content after 24 hai, increased malondialdehyde (MDA) content at the beginning of infection (3, 15 hai) while induction of catalase (CAT), APX and PPO was delayed. FHB-susceptible variety ‘Golubica’ involved antioxidant enzymes in defense response much later. Based on our results the activity of antioxidant enzymes (APX and PPO) was more pronounced in ‘Vulkan’ than in FHB-medium resistant variety ‘Kraljica’ and FHB-susceptible ‘Golubica’. The differences in antioxidant response of wheat varieties under Fusarium infestation could be the result of genetic properties.

      PubDate: 2017-03-17T10:05:08Z
      DOI: 10.1016/j.plaphy.2017.03.010
      Issue No: Vol. 115 (2017)
       
  • Apoplastic gamma-glutamyl transferase activity encoded by GGT1 and GGT2 is
           important for vegetative and generative development
    • Authors: Sabrina Giaretta; Dinesh Prasad; Ilaria Forieri; Teofilo Vamerali; Anna Rita Trentin; Markus Wirtz; Rüdiger Hell; Antonio Masi
      Pages: 44 - 56
      Abstract: Publication date: Available online 10 March 2017
      Source:Plant Physiology and Biochemistry
      Author(s): Sabrina Giaretta, Dinesh Prasad, Ilaria Forieri, Teofilo Vamerali, Anna Rita Trentin, Markus Wirtz, Rüdiger Hell, Antonio Masi
      Gamma-glutamyl transferase (GGT; EC 2.3.2.2) is the only enzyme capable of degrading glutathione (GSH) in extra-cytosolic spaces. In plant cells, the GGT1 and GGT2 isoforms are located in the apoplast, bound respectively to the cell wall and the plasma membrane. GGT1 is expressed throughout plants, mainly in the leaves and vascular system, while GGT2 is more specifically expressed in seeds and trichomes, and weakly in roots. Their role in plant physiology remains to be clarified, however. Obtaining the ggt1/ggt2 double mutant can offer more clues than the corresponding single mutants, and to prevent any compensatory expression between the two isoforms. In this work, ggt1/ggt2 RNAi (RNA interference) lines were generated and characterized in the tissues where both isoforms are expressed. The seed yield was lower in the ggt1/ggt2 RNAi plants due to the siliques being fewer in number and shorter in length, with no changes in thiols and sulfur compounds. Proline accumulation and delayed seed germination were seen in one line. There were also fewer trichomes (which contain high levels of GSH) in the RNAi lines than in the wild type, and the root elongation rate was slower. In conclusion, apoplastic GGT silencing induces a decrease in the number of organs with a high GSH demand (seeds and trichomes) as a result of resource reallocation to preserve integrity and composition.
      Graphical abstract image

      PubDate: 2017-03-17T10:05:08Z
      DOI: 10.1016/j.plaphy.2017.03.007
      Issue No: Vol. 115 (2017)
       
  • Thermal stress impacts reproductive development and grain yield in rice
    • Authors: Muhammad Shakeel Arshad; Muhammad Farooq; Folkard Asch; Jagadish S.V. Krishna; P.V. Vara Prasad; Kadambot H.M. Siddique
      Pages: 57 - 72
      Abstract: Publication date: Available online 16 March 2017
      Source:Plant Physiology and Biochemistry
      Author(s): Muhammad Shakeel Arshad, Muhammad Farooq, Folkard Asch, Jagadish S.V. Krishna, P.V. Vara Prasad, Kadambot H.M. Siddique
      Rice is highly sensitive to temperature stress (cold and heat), particularly during the reproductive and grain-filling stages. In this review, we discuss the effects of low- and high-temperature sensitivity in rice at various reproductive stages (from meiosis to grain development) and propose strategies for improving the tolerance of rice to terminal thermal stress. Cold stress impacts reproductive development through (i) delayed heading, due to its effect on anther respiration, which increases sucrose accumulation, protein denaturation and asparagine levels, and decreases proline accumulation, (ii) pollen sterility owing to tapetal hypertrophy and related nutrient imbalances, (iii) reduced activity of cell wall bound invertase in the tapetum of rice anthers, (iv) impaired fertilization due to inhibited anther dehiscence, stigma receptivity and ability of the pollen tube to germinate through the style towards the ovary, and (v) floret sterility, which increases grain abortion, restricts grain size, and thus reduces grain yield. Heat stress affects grain formation and development through (i) poor anther dehiscence due to restricted closure of the locules, leading to reduced pollen dispersal and fewer pollen on the stigma, (ii) changes in pollen proteins resulting in significant reductions in pollen viability and pollen tube growth, leading to spikelet sterility, (iii) delay in heading, (iv) reduced starch biosynthesis in developing grain, which reduces starch accumulation, (v) increased chalkiness of grain with irregular and round-shaped starch granules, and (vi) a shortened grain-filling period resulting in low grain weight. However, physiological and biotechnological tools, along with integrated management and adaptation options, as well as conventional breeding, can help to develop new rice genotypes possessing better grain yield under thermal stress during reproductive and grain-filling phases.

      PubDate: 2017-03-17T10:05:08Z
      DOI: 10.1016/j.plaphy.2017.03.011
      Issue No: Vol. 115 (2017)
       
  • A barley homolog of yeast ATG6 is involved in multiple abiotic stress
           responses and stress resistance regulation
    • Authors: Xiaowei Zeng; Zhanghui Zeng; Cuicui Liu; Weiyi Yuan; Ning Hou; Hongwu Bian; Muyuan Zhu; Ning Han
      Pages: 97 - 106
      Abstract: Publication date: Available online 19 March 2017
      Source:Plant Physiology and Biochemistry
      Author(s): Xiaowei Zeng, Zhanghui Zeng, Cuicui Liu, Weiyi Yuan, Ning Hou, Hongwu Bian, Muyuan Zhu, Ning Han
      Autophagy is a highly conserved degradation pathway among eukaryote cells, which can recycle damaged or unwanted cell materials upon encountering stress conditions. As a key component of the Class III PI3K kinase complex, ATG6/Beclin-1 is essential for autophagosome formation. In this study, we isolated a putative HvATG6 gene in barley genome. The protein encoded by HvATG6 shares high sequence identity to ATG6 orthologs in rice and wheat, and has a typical autophagy-specific domain containing segments of repeated β-sheet-α-helix. The expression of HvATG6 protein restored the appearance of autophagosomes in yeast atg6 mutant, indicating that HvATG6 complements the deficiency of yeast ATG6 protein in autophagy. Punctate florescence signals, considered as the PAS for autophagosome initiation, were observed in the cytoplasm of cells when HvATG6-GFP fusion construct was transformed into barley protoplast. Furthermore, the expression of HvATG6 was upregulated by various abiotic stresses including dark, H2O2 treatment, nitrogen deficiency, high salinity, drought, low temperature and toxic aluminum. Knockdown of HvATG6 in barley leaves through barley strip mosaic virus (BSMV)-induced gene silencing led to accelerated yellowing under dark and H2O2 treatments. Based on the above findings, we propose that barley ATG6 plays the similar role as other plant ATG6 orthologs, and might be involved in stress-induced autophagy process.

      PubDate: 2017-03-21T19:17:30Z
      DOI: 10.1016/j.plaphy.2017.03.013
      Issue No: Vol. 115 (2017)
       
  • Impact of endophytic colonization patterns on Zamioculcas zamiifolia
           stress response and in regulating ROS, tryptophan and IAA levels under
           airborne formaldehyde and formaldehyde-contaminated soil conditions
    • Authors: Gholamreza Khaksar; Chairat Treesubsuntorn; Paitip Thiravetyan
      Pages: 1 - 9
      Abstract: Publication date: May 2017
      Source:Plant Physiology and Biochemistry, Volume 114
      Author(s): Gholamreza Khaksar, Chairat Treesubsuntorn, Paitip Thiravetyan
      Deeper understanding of plant-endophyte interactions under abiotic stress would provide new insights into phytoprotection and phytoremediation enhancement. Many studies have investigated the positive role of plant-endophyte interactions in providing protection to the plant against pollutant stress through auxin (indole-3-acetic acid (IAA)) production. However, little is known about the impact of endophytic colonization patterns on plant stress response in relation to reactive oxygen species (ROS) and IAA levels. Moreover, the possible effect of pollutant phase on plant stress response is poorly understood. Here, we elucidated the impact of endophytic colonization patterns on plant stress response under airborne formaldehyde compared to formaldehyde-contaminated soil. ROS, tryptophan and IAA levels in the roots and shoots of endophyte-inoculated and non-inoculated plants in the presence and absence of formaldehyde were measured. Strain-specific quantitative polymerase chain reaction (qPCR) was used to investigate dynamics of endophyte colonization. Under the initial exposure to airborne formaldehyde, non-inoculated plants accumulated more tryptophan in the shoots (compared to the roots) to synthesize IAA. However, endophyte-inoculated plants behaved differently as they synthesized and accumulated more tryptophan in the roots and, hence, higher levels of IAA accumulation and exudation within roots which might act as a signaling molecule to selectively recruit B. cereus ERBP. Under continuous airborne formaldehyde stress, higher levels of ROS accumulation in the shoots pushed the plant to synthesize more tryptophan and IAA in the shoots (compared to the roots). Higher levels of IAA in the shoots might act as the potent driving force to relocalize B. cereus ERBP from roots to the shoots. In contrast, under formaldehyde-contaminated soil, B. cereus ERBP colonized root tissues without moving to the shoots since there was a sharp increase in ROS, tryptophan and IAA levels of the roots without any significant increase in the shoots. Pollutant phase affected endophytic colonization patterns and plant stress responses differently.
      Graphical abstract image

      PubDate: 2017-03-04T09:07:29Z
      DOI: 10.1016/j.plaphy.2017.02.016
      Issue No: Vol. 114 (2017)
       
  • The wheat mutant DELLA-encoding gene (Rht-B1c) affects plant
           photosynthetic responses to cadmium stress
    • Authors: Anelia G. Dobrikova; Ekaterina K. Yotsova; Andreas Börner; Svetlana P. Landjeva; Emilia L. Apostolova
      Pages: 10 - 18
      Abstract: Publication date: May 2017
      Source:Plant Physiology and Biochemistry, Volume 114
      Author(s): Anelia G. Dobrikova, Ekaterina K. Yotsova, Andreas Börner, Svetlana P. Landjeva, Emilia L. Apostolova
      Тhe sensitivity to cadmium (Cd) stress of two near-isogenic wheat lines with differences at the Rht-B1 locus, Rht-B1a (tall wild type, encoding DELLA proteins) and Rht-B1c (dwarf mutant, encoding modified DELLA proteins), was investigated. The effects of 100 μM CdCl2 on plant growth, pigment content and functional activity of the photosynthetic apparatus of wheat seedlings grown on a nutrient solution were evaluated through a combination of PAM chlorophyll fluorescence, oxygen evolution, oxidation-reduction kinetics of P700 and 77 K fluorescence. The results showed that the wheat mutant (Rht-B1c) was more tolerant to Cd stress compared to the wild type (Rht-B1a), as evidenced by the lower reductions in plant growth and pigment content, lower inhibition of photosystem I (PSI) and photosystem II (PSII) photochemistry and of the oxygen evolution measured with Clark-type and Joliot-type electrodes. Furthermore, the enhanced Cd tolerance was accompanied by increased Cd accumulation within mutant plant tissues. The molecular mechanisms through which the Rht-B1c mutation improves plant tolerance to Cd stress involve structural alterations in the mutant photosynthetic membranes leading to better protection of the Mn cluster of oxygen-evolving complex and increased capacity for PSI cyclic electron transport, protecting photochemical activity of the photosynthetic apparatus under stress. This study suggests a role for the Rht-B1c-encoded DELLA proteins in protective mechanisms and tolerance of the photosynthetic apparatus in wheat plants exposed to heavy metals stress.
      Graphical abstract image

      PubDate: 2017-03-04T09:07:29Z
      DOI: 10.1016/j.plaphy.2017.02.015
      Issue No: Vol. 114 (2017)
       
  • Comparative study of withanolide production and the related
           transcriptional responses of biosynthetic genes in fungi elicited cell
           suspension culture of Withania somnifera in shake flask and bioreactor
    • Authors: Seema Ahlawat; Parul Saxena; Athar Ali; Shazia Khan; Malik Z. Abdin
      Pages: 19 - 28
      Abstract: Publication date: May 2017
      Source:Plant Physiology and Biochemistry, Volume 114
      Author(s): Seema Ahlawat, Parul Saxena, Athar Ali, Shazia Khan, Malik Z. Abdin
      Ashwagandha (Withania somnifera) is one of the most reputed medicinal plants in the traditional medicinal system. In this study, cell suspension culture of W. somnifera was elicited with cell homogenates of fungi (A. alternata, F. solani, V. dahliae and P. indica) in shake flask and the major withanolides like withanolide A, withaferin A and withanone were analysed. Simultaneously expression levels of key pathway genes from withanolides biosynthetic pathways were also checked via quantitative PCR in shake flask as well as in bioreactor. The results show that highest gene expression of 10.8, 5.8, 4.9, and 3.3 folds were observed with HMGR among all the expressed genes in cell suspension cultures with cell homogenates of 3% P. indica, 5% V. dahliae, 3% A. alternata and 3% F. solani, respectively, in comparison to the control in shake flask. Optimized concentration of cell homogenate of P. indica (3% v/v) was added to the growing culture in 5.0-l bioreactor under optimized up-scaling conditions and harvested after 22 days. The genes of MVA, MEP and withanolides biosynthetic pathways like HMGR, SS, SE, CAS, FPPS, DXR and DXS were up-regulated by 12.5, 4.9, 2.18, 4.65, 2.34, 1.89 and 1.4 folds, respectively in bioreactor. The enhancement of biomass (1.13 fold) and withanolides [withanolide A (1.7), withaferin A (1.5), and withanone (1.5) folds] in bioreactor in comparison to shake flask was also found to be in line with the up-regulation of genes of withanolide biosynthetic pathways.

      PubDate: 2017-03-04T09:07:29Z
      DOI: 10.1016/j.plaphy.2017.02.013
      Issue No: Vol. 114 (2017)
       
  • Cadmium-induced changes in vacuolar aspects of Arabidopsis thaliana
    • Authors: Shanti S. Sharma; Kotaro Yamamoto; Kohei Hamaji; Miwa Ohnishi; Aya Anegawa; Shashi Sharma; Sveta Thakur; Vijay Kumar; Tomohiro Uemura; Akihiko Nakano; Tetsuro Mimura
      Pages: 29 - 37
      Abstract: Publication date: May 2017
      Source:Plant Physiology and Biochemistry, Volume 114
      Author(s): Shanti S. Sharma, Kotaro Yamamoto, Kohei Hamaji, Miwa Ohnishi, Aya Anegawa, Shashi Sharma, Sveta Thakur, Vijay Kumar, Tomohiro Uemura, Akihiko Nakano, Tetsuro Mimura
      We have examined the changes due to Cd treatment in the vacuolar form in root tip cortical cells in Arabidopsis thaliana employing a transformant with GFP fused to a tonoplast protein. A Cd-induced enhancement in complexity with general expansion of vacuolar system within 24 h was evident. The changes in the vacuolar form were dependent on the applied Cd concentrations. Concomitantly, as revealed through dithizone staining, Cd accumulated in the seedling roots exhibiting abundance of Cd-dithizone complexes in root tip, root hairs and vasculature. To get insight into the involvement of SNARE protein-mediated vesicle fusion in Cd detoxification, the magnitude of Cd toxicity in a couple of knock out mutants of the vacuolar Qa-SNARE protein VAM3/SYP22 was compared with that in the wild type. The Cd toxicity appeared to be comparable in the mutants and the wild type. In order to analyze the Cd effects at cellular level, we treated the Arabidopsis suspension-cultured cells with Cd. Cd, however, did not induce a change in the vacuolar form in suspension-cultured cells although Cd measured with ICP-MS was obviously taken up into the cell. The V-ATPase activity in the microsomal fractions from vacuoles isolated from A. thaliana suspension cultured cells remained unaffected by Cd. Changes in the levels of certain metabolites of Cd-treated cells were also not so distinct except for those of glutathione. The significance of findings is discussed.

      PubDate: 2017-03-04T09:07:29Z
      DOI: 10.1016/j.plaphy.2017.02.017
      Issue No: Vol. 114 (2017)
       
  • Effects of cadmium-resistant fungi Aspergillus aculeatus on metabolic
           profiles of bermudagrass [Cynodondactylon (L.)Pers.] under Cd stress
    • Authors: Xiaoning Li; Margaret Mukami Gitau; Shijuan Han; Jinmin Fu; Yan Xie
      Pages: 38 - 50
      Abstract: Publication date: May 2017
      Source:Plant Physiology and Biochemistry, Volume 114
      Author(s): Xiaoning Li, Margaret Mukami Gitau, Shijuan Han, Jinmin Fu, Yan Xie
      Plants' tolerance to heavy metal stress may be induced by the exploitation of microbes. The objectives of this study were to investigate the effect of cadmium (Cd)-resistant fungus, Aspergillus aculeatus, on tolerance to Cd and alteration of metabolites in bermudagrass under Cd stress, and identify the predominant metabolites associated with Cd tolerance. Two genotypes of bermudagrass with contrasting Cd tolerance (Cd-sensitive ‘WB92’ and Cd-tolerant ‘WB242’) were exposed to 0, 50, 150 and 250 mg kg−1 Cd for 21 days. Physiological responses of bermudagrass to Cd stress were evaluated based on the relative growth rate (RGR) and normalized relative transpiration rate (NRT). Plants inoculated with A. aculeatus exhibited higher RGR and NRT under Cd stress than those of non-inoculated plants, regardless of genotypes. A total of 32 Cd-responsive metabolites in leaves and 21 in roots were identified in the two genotypes, including organic acids, amino acids, sugars, and fatty acids and others. Interestingly, under Cd stress, the leaves of inoculated ‘WB92’ accumulated less citric acid, aspartic acid, glutamic acid, sucrose, galactose, but more sorbose and glucose, while inoculated ‘WB242’ leaves had less citric acid, malic acid, sucrose, sorbose, but more fructose and glucose, compared to non-inoculated plants. In ‘WB92’ roots, the A. aculeatus reduced mannose content, but increased trehalose and citric acid content, while in ‘WB242’, it decreased sucrose, but enhanced citric acid content, compared to Cd regime. The results of this study suggest that A. aculeatus may induce accumulation of different metabolites associated with Cd tolerance in bermudagrass.

      PubDate: 2017-03-21T19:17:30Z
      DOI: 10.1016/j.plaphy.2017.02.014
      Issue No: Vol. 114 (2017)
       
  • Antioxidant defense during desiccation of the resurrection plant Haberlea
           rhodopensis
    • Authors: Katya Georgieva; Soleya Dagnon; Emiliya Gesheva; Dimitar Bojilov; Gergana Mihailova; Snezhana Doncheva
      Pages: 51 - 59
      Abstract: Publication date: May 2017
      Source:Plant Physiology and Biochemistry, Volume 114
      Author(s): Katya Georgieva, Soleya Dagnon, Emiliya Gesheva, Dimitar Bojilov, Gergana Mihailova, Snezhana Doncheva
      Maintaining a strong antioxidant system is essential for preventing drought-induced oxidative stress. Thus, in the present study we investigated the role of some non-enzymic and enzymic antioxidants in desiccation tolerance of Haberlea rhodopensis. The effects of high light upon desiccation on antioxidant capacity was estimated by comparing the response of shade and sun plants. The significant enhancement of the antioxidant capacity at 8% RWC corresponded to an enormous increase in flavonoid content. The important role of ascorbate-glutathione cycle in overcoming oxidative stress during drying of H. rhodopensis was established. The antioxidant capacity increased upon dehydration of both shade and sun plants but some differences in non-enzymatic and enzymatic antioxidants were observed. Investigations on the role of polyphenols in desiccation tolerance are scarce. In the present study the polyphenol profiles (fingerprints) of the resurrection plant Haberlea rhodopensis, including all components of the complex are obtained for the first time. It was clarified that the polyphenol complex of H. rhodopensis includes only two types of glycosides - phenylethanoid glucosides and hispidulin 8-C-glucosides. Upon desiccation the polyphenol content increase and the main role of phenylethanoid glucosides in the protection of H. rhodopensis was revealed.

      PubDate: 2017-03-21T19:17:30Z
      DOI: 10.1016/j.plaphy.2017.02.021
      Issue No: Vol. 114 (2017)
       
  • A Glycine max homolog of NON-RACE SPECIFIC DISEASE RESISTANCE 1 (NDR1)
           alters defense gene expression while functioning during a resistance
           response to different root pathogens in different genetic backgrounds
    • Authors: Brant T. McNeece; Shankar R. Pant; Keshav Sharma; Prakash Niruala; Gary W. Lawrence; Vincent P. Klink
      Pages: 60 - 71
      Abstract: Publication date: May 2017
      Source:Plant Physiology and Biochemistry, Volume 114
      Author(s): Brant T. McNeece, Shankar R. Pant, Keshav Sharma, Prakash Niruala, Gary W. Lawrence, Vincent P. Klink
      A Glycine max homolog of the Arabidopsis thaliana NON-RACE SPECIFIC DISEASE RESISTANCE 1 (NDR1) coiled-coil nucleotide binding leucine rich repeat (CC-NB-LRR) defense signaling gene (Gm-NDR1-1) is expressed in root cells undergoing a defense response to the root pathogenic nematode, Heterodera glycines. Gm-NDR1-1 overexpression in the H. glycines-susceptible genotype G. max [Williams 82/PI 518671] impairs parasitism. In contrast, Gm-NDR1-1 RNA interference (RNAi) in the H. glycines-resistant genotype G. max [Peking/PI 548402] facilitates parasitism. The broad effectiveness of Gm-NDR1-1 in impairing parasitism has then been examined by engineering its heterologous expression in Gossypium hirsutum which is susceptible to the root pathogenic nematode Meloidogyne incognita. The heterologous expression of Gm-NDR1-1 in G. hirsutum effectively impairs M. incognita parasitism, reducing gall, egg mass, egg and juvenile numbers. In contrast to our prior experiments examining the effectiveness of the heterologous expression of a G. max homolog of the A. thaliana salicyclic acid signaling (SA) gene NONEXPRESSOR OF PR1 (Gm-NPR1-2), no cumulative negative effect on M. incognita parasitism has been observed in G. hirsutum expressing Gm-NDR1-1. The results indicate a common genetic basis exists for plant resistance to parasitic nematodes that involves Gm-NDR1. However, the Gm-NDR1-1 functions in ways that are measurably dissimilar to Gm-NPR1-2. Notably, Gm-NDR1-1 overexpression leads to increased relative transcript levels of its homologs of A. thaliana genes functioning in SA signaling, including NPR1-2, TGA2-1 and LESION SIMULATING DISEASE1 (LSD1-2) that is lost in Gm-NDR1-1 RNAi lines. Similar observations have been made regarding the expression of other defense genes.

      PubDate: 2017-03-10T09:18:47Z
      DOI: 10.1016/j.plaphy.2017.02.022
      Issue No: Vol. 114 (2017)
       
  • Changes in the mitochondrial protein profile due to ROS eruption during
           ageing of elm (Ulmus pumila L.) seeds
    • Authors: Ying Li; Yu Wang; Hua Xue; Hugh W. Pritchard; Xiaofeng Wang
      Pages: 72 - 87
      Abstract: Publication date: May 2017
      Source:Plant Physiology and Biochemistry, Volume 114
      Author(s): Ying Li, Yu Wang, Hua Xue, Hugh W. Pritchard, Xiaofeng Wang
      Reactive oxygen species (ROS)-related mitochondrial dysfunction is considered to play a vital role in seed deterioration. However, the detailed mechanisms remain largely unknown. To address this, a comparison of mitochondrial proteomes was performed, and we identified several proteins that changed in abundance with accompanying ROS eruption and mitochondrial aggregation and diffusion. These are involved in mitochondrial metabolisms, stress resistance, maintenance of structure and intracellular transport during seed aging. Reduction of ROS content by the mitochondrial-specific scavenger MitoTEMPO suppressed these changes, whereas pre-treatment of seeds with methyl viologen (MV) had the opposite effect. Furthermore, voltage-dependent anion channels (VDAC) were found to increase both in abundance and carbonylation level, accompanied by increased cytochrome c (cyt c) release from mitochondria to cytosol, indicating the profound effect of ROS and VDAC on mitochondria-dependent cell death. Carbonylation detection revealed the specific target proteins of oxidative modification in mitochondria during ageing. Notably, membrane proteins accounted for a large proportion of these targets. An in vitro assay demonstrated that the oxidative modification was concomitant with a change of VDAC function and a loss of activity in malate dehydrogenase. Our data suggested that ROS eruption induced alteration and modification of specific mitochondrial proteins that may be involved in the process of mitochondrial deterioration, which eventually led to loss of seed viability.

      PubDate: 2017-03-10T09:18:47Z
      DOI: 10.1016/j.plaphy.2017.02.023
      Issue No: Vol. 114 (2017)
       
  • Phosphite shifts physiological and hormonal profile of Monterey pine and
           delays Fusarium circinatum progression
    • Authors: Andreia Cerqueira; Artur Alves; Helder Berenguer; Barbara Correia; Aurelio Gómez-Cadenas; Julio Javier Diez; Pedro Monteiro; Glória Pinto
      Pages: 88 - 99
      Abstract: Publication date: May 2017
      Source:Plant Physiology and Biochemistry, Volume 114
      Author(s): Andreia Cerqueira, Artur Alves, Helder Berenguer, Barbara Correia, Aurelio Gómez-Cadenas, Julio Javier Diez, Pedro Monteiro, Glória Pinto
      Fusarium circinatum is the causal agent of pitch canker disease affecting Pinus spp. and Pseudotsuga menziesii worldwide. Under strict quarantine measures, alternative approaches for disease control are necessary. Phosphite (Phi) salts are known for their fungicidal activity and as plant resistance elicitors; however, its potential is yet to be acknowledged in the Pinus-F. circinatum model. The main aim of this study was to assess whether the application of a Phi-based commercial formulation would delay the progression of the pitch canker on Pinus radiata plants, and on the in vitro fungal growth. In vitro assays were performed using different Phi concentrations (1% and 4%) and a non-treated control (0%), and repeated in vivo using inoculated and non-inoculated plants. Plant physiological parameters and hormonal content were evaluated. Phi was effective at inhibiting in vitro mycelial growth in a dose dependent manner. Regardless of fungal inoculation, Phi application induced positive effects on plant performance, despite phytotoxic effects found at 4%. Fusarium circinatum infection led to a reduction in gas exchange and chlorophyll fluorescence (Fv/Fm and φPSII), while proline and hormone (JA, ABA and SA) levels increased. Phi was effective in delaying disease symptom development in a dose dependent manner, concurrent with in vitro observations: gas exchange and chlorophyll fluorescence (Fv/Fm) were unaffected; proline, MDA and ABA decreased; electrolyte leakage and total soluble sugars increased. This suggests a direct (pathogen growth inhibition) and indirect (host defense priming) action of Phi, showing that Phi represents a potential strategy to control F. circinatum infection.

      PubDate: 2017-03-10T09:18:47Z
      DOI: 10.1016/j.plaphy.2017.02.020
      Issue No: Vol. 114 (2017)
       
  • A salt-stress-regulator from the Poplar R2R3 MYB family integrates the
           regulation of lateral root emergence and ABA signaling to mediate salt
           stress tolerance in Arabidopsis
    • Authors: Qing Fang; Tianzhi Jiang; Liangxiang Xu; Hai Liu; Hui Mao; Xianqiang Wang; Bo Jiao; Yanjiao Duan; Qiong Wang; Qiannan Dong; Li Yang; Guozheng Tian; Chi Zhang; Yifeng Zhou; Xiaopeng Liu; Haiyang Wang; Di Fan; Bangjun Wang; Keming Luo
      Pages: 100 - 110
      Abstract: Publication date: May 2017
      Source:Plant Physiology and Biochemistry, Volume 114
      Author(s): Qing Fang, Tianzhi Jiang, Liangxiang Xu, Hai Liu, Hui Mao, Xianqiang Wang, Bo Jiao, Yanjiao Duan, Qiong Wang, Qiannan Dong, Li Yang, Guozheng Tian, Chi Zhang, Yifeng Zhou, Xiaopeng Liu, Haiyang Wang, Di Fan, Bangjun Wang, Keming Luo
      The roles of most MYB transcription factors (TFs) in the poplar remain unclear. Here, we demonstrate that PtrSSR1, a salt-stress-regulator in the Populus trichocarpa R2R3 MYB gene family, mediates the tolerance of transgenic Arabidopsis plants to salt stress. The transcripts of PtrSSR1 could be induced by salt stress rapidly in poplar. Subcellular localization and yeast assays indicated that PtrSSR1 encoded a nuclear protein with transactivation activity. The Arabidopsis transformants overexpressing PtrSSR1 clearly displayed lateral root emergence (LRE) inhibition compared with wild-type (Wt) under normal conditions; while upon NaCl treatment, the transformants showed improved tolerance, and the LRs emerged faster from salt-induced inhibition. A strong correlation could exist between the LRE mediated by PtrSSR1 and abscisic acid (ABA), mainly because the transformants displayed more sensitivity to exogenous ABA during both seed germination and LRE, and had a distinctly increased level of endogenous ABA. Furthermore, several ABA- and salt-related genes, such as NCED3, ABI1 and CBL1, were up-regulated. Thus, our results suggest that elevation in the endogenous ABA content bring alteration of plant LR development, and that the poplar R2R3 MYB TF PtrSSR1 vitally improve salt stress tolerance by integrating the regulation of LRE and ABA signaling in Arabidopsis.

      PubDate: 2017-03-10T09:18:47Z
      DOI: 10.1016/j.plaphy.2017.02.018
      Issue No: Vol. 114 (2017)
       
  • Silencing of the FRO1 gene and its effects on iron partition in Nicotiana
           benthamiana
    • Authors: Florinda Gama; Teresa Saavedra; Susana Dandlen; Amarilis de Varennes; Pedro J. Correia; Maribela Pestana; Gustavo Nolasco
      Pages: 111 - 118
      Abstract: Publication date: May 2017
      Source:Plant Physiology and Biochemistry, Volume 114
      Author(s): Florinda Gama, Teresa Saavedra, Susana Dandlen, Amarilis de Varennes, Pedro J. Correia, Maribela Pestana, Gustavo Nolasco
      To evaluate the dynamic role of the ferric-chelate reductase enzyme (FCR) and to identify possible pathways of regulation of its activity in different plant organs an investigation was conducted by virus-induced gene silencing (VIGS) using tobacco rattle virus (TRV) to silence the ferric reductase oxidase gene (FRO1) that encodes the FCR enzyme. Half of Nicotiana benthamiana plants received the VIGS vector and the rest remained as control. Four treatments were imposed: two levels of Fe in the nutrient solution (0 or 2.5 μM of Fe), each one with silenced or non-silenced (VIGS-0; VIGS-2.5) plants. Plants grown without iron (0; VIGS-0) developed typical symptoms of iron deficiency in the youngest leaves. To prove that FRO1 silencing had occurred, resupply of Fe (R) was done by adding 2.5 μM of Fe to the nutrient solution in a subset of chlorotic plants (0-R; VIGS-R). Twelve days after resupply, 0-R plants had recovered from Fe deficiency while plants containing the VIGS vector (VIGS-R) remained chlorotic and both FRO1 gene expression and FCR activity were considerably reduced, consequently preventing Fe uptake. With the VIGS technique we were able to silence the FRO1 gene in N. benthamiana and point out its importance in chlorophyll synthesis and Fe partition.

      PubDate: 2017-03-10T09:18:47Z
      DOI: 10.1016/j.plaphy.2017.03.004
      Issue No: Vol. 114 (2017)
       
  • Water use efficiency and shoot biomass production under water limitation
           is negatively correlated to the discrimination against 13C in the C3
           grasses Dactylis glomerata, Festuca arundinacea and Phalaris arundinacea
    • Authors: Linda-Maria Mårtensson; Georg Carlsson; Thomas Prade; Kirsten Kørup; Poul Erik Lærke; Erik Steen Jensen
      Pages: 1 - 5
      Abstract: Publication date: April 2017
      Source:Plant Physiology and Biochemistry, Volume 113
      Author(s): Linda-Maria Mårtensson, Georg Carlsson, Thomas Prade, Kirsten Kørup, Poul Erik Lærke, Erik Steen Jensen
      Climate change impacts rainfall patterns which may lead to drought stress in rain-fed agricultural systems. Crops with higher drought tolerance are required on marginal land with low precipitation or on soils with low water retention used for biomass production. It is essential to obtain plant breeding tools, which can identify genotypes with improved drought tolerance and water use efficiency (WUE). In C3 plant species, the variation in discrimination against 13C (Δ13C) during photosynthesis has been shown to be a potential indicator for WUE, where discrimination against 13C and WUE were negatively correlated. The aim of this study was to determine the variation in the discrimination against 13C between species and cultivars of three perennial C3 grasses (Dactylis glomerata (cocksfoot), Festuca arundinacea (tall fescue) and Phalaris arundinacea (reed canary grass)) and test the relationships between discrimination against 13C, season-long water use WUEB, shoot and root biomass production in plants grown under well-watered and water-limited conditions. The grasses were grown in the greenhouse and exposed to two irrigation regimes, which corresponded to 25% and 60% water holding capacity, respectively. We found negative relationships between discrimination against 13C and WUEB and between discrimination against 13C and shoot biomass production, under both the well-watered and water-limited growth conditions (p < 0.001). Discrimination against 13C decreased in response to water limitation (p < 0.001). We found interspecific differences in the discrimination against 13C, WUEB, and shoot biomass production, where the cocksfoot cultivars showed lowest and the reed canary grass cultivars highest values of discrimination against 13C. Cocksfoot cultivars also showed highest WUEB, shoot biomass production and potential tolerance to water limitation. We conclude that discrimination against 13C appears to be a useful indicator, when selecting C3 grass crops for biomass production under drought conditions.

      PubDate: 2017-02-05T11:37:43Z
      DOI: 10.1016/j.plaphy.2017.01.021
      Issue No: Vol. 113 (2017)
       
  • Physiological highlights of manganese toxicity symptoms in soybean plants:
           Mn toxicity responses
    • Authors: Elcio Ferreira Santos; José Mateus Kondo Santini; Amanda Pereira Paixão; Enes Furlani Júnior; José Lavres; Marcelo Campos; André Rodrigues dos Reis
      Pages: 6 - 19
      Abstract: Publication date: April 2017
      Source:Plant Physiology and Biochemistry, Volume 113
      Author(s): Elcio Ferreira Santos, José Mateus Kondo Santini, Amanda Pereira Paixão, Enes Furlani Júnior, José Lavres, Marcelo Campos, André Rodrigues dos Reis
      Manganese (Mn) is an essential element for plants; however, high concentrations in certain soil conditions can cause toxicity symptoms in the plant tissue. Here, we describe Mn toxicity symptoms and Mn toxicity responses in soybean plants. Soybean plants exposed to excess Mn showed reductions in the CO2 assimilation rate and stomatal conductance, which in turn resulted in decreased shoot biomass. Furthermore, peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activity were higher in plants grown with the highest Mn concentration. The Mn doses increased the activity of antioxidant enzymes such as CAT, POD, and SOD. The toxicity symptoms presented by the leaves included hypertrophying of the adaxial epidermis and the formation of necrotic areas with purple-colored veins. Dramatic movement of calcium from the healthy region to the purple-colored necrotic region was observed, as was the exit of potassium from the necrotic area to the healthy region of the tissue. The high activities of POD and SOD in the presence of high Mn compartmented in the roots was the main physiological responses at high Mn uptake by soybean plants.
      Graphical abstract image

      PubDate: 2017-02-05T11:37:43Z
      DOI: 10.1016/j.plaphy.2017.01.022
      Issue No: Vol. 113 (2017)
       
  • Glucose and sucrose differentially modify cell proliferation in maize
           during germination
    • Authors: Aurora Lara-Núñez; Brendy B. García-Ayala; Sara M. Garza-Aguilar; Jesús Flores-Sánchez; Victor A. Sánchez-Camargo; Carlos E. Bravo-Alberto; Sonia Vázquez-Santana; Jorge M. Vázquez-Ramos
      Pages: 20 - 31
      Abstract: Publication date: April 2017
      Source:Plant Physiology and Biochemistry, Volume 113
      Author(s): Aurora Lara-Núñez, Brendy B. García-Ayala, Sara M. Garza-Aguilar, Jesús Flores-Sánchez, Victor A. Sánchez-Camargo, Carlos E. Bravo-Alberto, Sonia Vázquez-Santana, Jorge M. Vázquez-Ramos
      Glucose and sucrose play a dual role: as carbon and energy sources and as signaling molecules. In order to address the impact that sugars may have on maize seeds during germination, embryo axes were incubated with or without either of the two sugars. Expression of key cell cycle markers and protein abundance, cell patterning and de novo DNA synthesis in root meristem zones were analyzed. Embryo axes without added sugars in imbibition medium were unable to grow after 7 days; in sucrose, embryo axes developed seminal and primary roots with numerous root hairs, whereas in glucose axes showed a twisted morphology, no root hair formation but callus-like structures on adventitious and primary seminal roots. More and smaller cells were observed with glucose treatment in root apical meristems. de novo DNA synthesis was stimulated more by glucose than by sucrose. At 24 h of imbibition, expression of ZmCycD2;2a and ZmCycD4;2 was increased by sucrose and reduced by glucose. CDKA1;1 and CDKA2;1 expression was stimulated equally by both sugars. Protein abundance patterns were modified by sugars: ZmCycD2 showed peaks on glucose at 12 and 36 h of imbibition whereas sucrose promoted ZmCycD3 protein accumulation. In presence of glucose ZmCycD3, ZmCycD4 and ZmCycD6 protein abundance was reduced after 24 h. Finally, both sugars stimulated ZmCDKA protein accumulation but at different times. Overall, even though glucose appears to act as a stronger mitogen stimulator, sucrose stimulated the expression of more cell cycle markers during germination. This work provides evidence of a differential response of cell cycle markers to sucrose and glucose during maize germination that may affect the developmental program during plantlet establishment.

      PubDate: 2017-02-05T11:37:43Z
      DOI: 10.1016/j.plaphy.2017.01.018
      Issue No: Vol. 113 (2017)
       
  • Adjustments in CAM and enzymatic scavenging of H2O2 in juvenile plants of
           the epiphytic bromeliad Guzmania monostachia as affected by drought and
           rewatering
    • Authors: Victória Carvalho; Maria E. Abreu; Helenice Mercier; Catarina C. Nievola
      Pages: 32 - 39
      Abstract: Publication date: April 2017
      Source:Plant Physiology and Biochemistry, Volume 113
      Author(s): Victória Carvalho, Maria E. Abreu, Helenice Mercier, Catarina C. Nievola
      Juvenile plants of epiphytes such as bromeliads are highly prone to dehydration under drought conditions. It is likely that young epiphytes evolved mostly metabolic strategies to resist drought, which may include the plastic modulation of the enzymatic antioxidant system and crassulacean acid metabolism (CAM). Few studies have investigated such strategies in juvenile epiphytes, although such research is important to understand how these plants might face drought intensification derived from potential climatic alterations. The epiphytic CAM bromeliad Guzmania monostachia (L.) Rusby ex Mez var. monostachia is known to have plastic responses to drought, but no reports have focused on the metabolism of juvenile plants to drought and recovery. Hence, we aimed to verify how juvenile G. monostachia plants adjust malate (indicative of CAM), H2O2 content and enzymatic scavenging in response to drought (eight days without irrigation) and rewatering (six days of irrigation post-drought). Interestingly, drought decreased H2O2 content and activities of superoxide dismutase, catalase (CAT) and ascorbate peroxidase (APX) in the pre-dusk period, although glutathione reductase (GR) and CAM activity increased. Rewatering restored H2O2, but activities of APX, CAT and GR exceeded pre-stress levels in the pre-dusk and/or pre-dawn periods. Results suggest that recovery from a first drought redefines the homeostatic balance of H2O2 scavenging, in which rewatered plants stimulate the enzymatic antioxidant system while drought-exposed plants intensify CAM activity to regulate H2O2 content, a photosynthetic pathway known to prevent oxidative stress. Such data show that young G. monostachia plants adjust CAM and H2O2 scavenging to adapt to water availability.

      PubDate: 2017-02-05T11:37:43Z
      DOI: 10.1016/j.plaphy.2017.01.024
      Issue No: Vol. 113 (2017)
       
  • Characterization of a small GTP-binding protein gene TaRab18 from wheat
           involved in the stripe rust resistance
    • Authors: Zhengning Jiang; Hui Wang; Guoqin Zhang; Renhui Zhao; Tongde Bie; Ruiqi Zhang; Derong Gao; Liping Xing; Aizhong Cao
      Pages: 40 - 50
      Abstract: Publication date: April 2017
      Source:Plant Physiology and Biochemistry, Volume 113
      Author(s): Zhengning Jiang, Hui Wang, Guoqin Zhang, Renhui Zhao, Tongde Bie, Ruiqi Zhang, Derong Gao, Liping Xing, Aizhong Cao
      The stripe rust resistance gene, Yr26, is commonly used in wheat production. Identification of Yr26 resistance related genes is important for better understanding of the resistance mechanism. TaRab18, a putative small GTP-binding protein, was screened as a resistance regulated gene as it showed differential expression between the Yr26-containing resistant wheat and the susceptible wheat at different time points after Pst inoculation. TaRab18 contains four typical domains (GI to GIV) of the small GTP-binding proteins superfamily and five domains (RabF1 to RabF5) specific to the Rab subfamily. From the phylogenetic tree that TaRab18 was identified as belonging to the RABC1 subfamily. Chromosome location analysis indicated that TaRab18 and its homeoalles were on the homeologous group 7 chromosomes, and the Pst induced TaRab18 was on the 7 B chromosome. Functional analysis by virus induced gene silencing (VIGS) indicated that TaRab18 was positively involved in the stripe rust resistance through regulating the hypersensitive response, and Pst can develop on the leaves of TaRab18 silenced 92R137. However, over-expression of TaRab18 in susceptible Yangmai158 did not enhance its resistance dramatically, only from 9 grade in Yangmai158 to 8 grade in the transgenic plant. However, histological observation indicated that the transgenic plants with over-expressed TaRab18 showed a strong hypersensitive response at the early infection stage. The research herein, will improve our understanding of the roles of Rab in wheat resistance.

      PubDate: 2017-02-12T07:09:07Z
      DOI: 10.1016/j.plaphy.2017.01.025
      Issue No: Vol. 113 (2017)
       
  • The suppression of tomato defence response genes upon potato cyst nematode
           infection indicates a key regulatory role of miRNAs
    • Authors: Magdalena Święcicka; Waldemar Skowron; Piotr Cieszyński; Joanna Dąbrowska-Bronk; Mateusz Matuszkiewicz; Marcin Filipecki; Marek Daniel Koter
      Pages: 51 - 55
      Abstract: Publication date: April 2017
      Source:Plant Physiology and Biochemistry, Volume 113
      Author(s): Magdalena Święcicka, Waldemar Skowron, Piotr Cieszyński, Joanna Dąbrowska-Bronk, Mateusz Matuszkiewicz, Marcin Filipecki, Marek Daniel Koter
      Potato cyst nematode Globodera rostochiensis is an obligate parasite of solanaceous plants, triggering metabolic and morphological changes in roots which may result in substantial crop yield losses. Previously, we used the cDNA-AFLP to study the transcriptional dynamics in nematode infected tomato roots. Now, we present the rescreening of already published, upregulated transcript-derived fragment dataset using the most current tomato transcriptome sequences. Our reanalysis allowed to add 54 novel genes to 135, already found as upregulated in tomato roots upon G. rostochiensis infection (in total - 189). We also created completely new catalogue of downregulated sequences leading to the discovery of 76 novel genes. Functional classification of candidates showed that the ‘wound, stress and defence response’ category was enriched in the downregulated genes. We confirmed the transcriptional dynamics of six genes by qRT-PCR. To place our results in a broader context, we compared the tomato data with Arabidopsis thaliana, revealing similar proportions of upregulated and downregulated genes as well as similar enrichment of defence related transcripts in the downregulated group. Since transcript suppression is quite common in plant–nematode interactions, we assessed the possibility of miRNA-mediated inverse correlation on several tomato sequences belonging to NB-LRR and receptor-like kinase families. The qRT-PCR of miRNAs and putative target transcripts showed an opposite expression pattern in 9 cases. These results together with in silico analyses of potential miRNA targeting to the full repertoire of tomato R-genes show that miRNA mediated gene suppression may be a key regulatory mechanism during nematode parasitism.

      PubDate: 2017-02-12T07:09:07Z
      DOI: 10.1016/j.plaphy.2017.01.026
      Issue No: Vol. 113 (2017)
       
  • Genome-wide characterization and expression profiling of the NAC genes
           under abiotic stresses in Cucumis sativus
    • Authors: Xiao Meng Zhang; Hong Jun Yu; Chao Sun; Jie Deng; Xue Zhang; Peng Liu; Yun Yun Li; Qiang Li; Wei Jie Jiang
      Pages: 98 - 109
      Abstract: Publication date: April 2017
      Source:Plant Physiology and Biochemistry, Volume 113
      Author(s): Xiao Meng Zhang, Hong Jun Yu, Chao Sun, Jie Deng, Xue Zhang, Peng Liu, Yun Yun Li, Qiang Li, Wei Jie Jiang
      The NAC (standing for no apical meristem [NAM], Arabidopsis transcription activation factor [ATAF] and cup-shaped cotyledon [CUC]) proteins pertain to one of the plant-specific transcription factor families that play important roles in plant development, abiotic stress resistance and signalling transduction. In the present study, the genomic features of the NAC genes in cucumber were analysed in depth using in silico tools. To reveal a tissue-specific, abiotic stress and hormone-responsive expression profile of CsNAC genes, RT-qPCR was performed under different treatments. Phylogenetic analyses and genome-wide annotation indicated that 82 high-confidence CsNAC genes were clustered into 13 sub-groups with uneven distribution in the cucumber genome. Furthermore, the CsNAC genes exhibited different tissue-specific expression patterns in 10 tissues under normal growth conditions, while 13 (16%) and 28 (34%) genes displayed preferential expression in roots and flowers, respectively. Moreover, CsNAC genes were more sensitive to salinity than other stresses; however, their responses were relatively rapid and transient to nutrition deprivation. Several CsNAC genes, including CsNAC35, which is an orthologue of the known stress-responsive Arabidopsis RD26, were identified as highly responsive to abiotic stresses and hormones. Overall, our findings revealed the genomic landscape and expression profiling of the CsNAC genes in response to multiple stresses and hormones, offering clues for further function analyses and molecular breeding.

      PubDate: 2017-02-12T07:09:07Z
      DOI: 10.1016/j.plaphy.2017.01.023
      Issue No: Vol. 113 (2017)
       
  • Effects of low sink demand on leaf photosynthesis under potassium
           deficiency
    • Authors: Yonghui Pan; Zhifeng Lu; Jianwei Lu; Xiaokun Li; Rihuan Cong; Tao Ren
      Pages: 110 - 121
      Abstract: Publication date: April 2017
      Source:Plant Physiology and Biochemistry, Volume 113
      Author(s): Yonghui Pan, Zhifeng Lu, Jianwei Lu, Xiaokun Li, Rihuan Cong, Tao Ren
      The interaction between low sink demand and potassium (K) deficiency in leaf photosynthesis was not intensively investigated, therefore this interaction was investigated in winter oilseed rape (Brassica napus L.). Plants subjected to sufficient (+K) or insufficient (−K) K supply treatments were maintained or removed their flowers and pods; these conditions were defined as high sink demand (HS) or low sink demand (LS), respectively. The low sink demand induced a lower photosynthetic rate (Pn), especially in the −K treatment during the first week. A negative relationship between Pn and carbohydrate concentration was observed in the −K treatment but not in the +K treatment, suggesting that the decrease in Pn in the −K treatment was the result of sink feedback regulation under low sink demand. Longer sink removal duration increased carbohydrate concentration, but the enhanced assimilate did not influence Pn. On the contrary, low sink demand resulted in a high K concentration, slower chloroplast degradation rate and better PSII activity, inducing a higher Pn compared with HS. Consequently, low sink demand decreased leaf photosynthesis over the short term due to sink feedback regulation, and potassium deficiency enhanced the photosynthetic decrease through carbohydrate accumulation and a lower carbohydrate concentration threshold for initiating photosynthesis depression. A longer duration of limited sink demand and sufficient potassium supply resulted in a higher photosynthesis rate because of delayed chloroplast degradation. This finding indicates that the nutritional status plays a role in leaf photosynthesis variations due to sink-source manipulation.

      PubDate: 2017-02-12T07:09:07Z
      DOI: 10.1016/j.plaphy.2017.01.027
      Issue No: Vol. 113 (2017)
       
  • Biochemical composition of symplastic sap from sugarcane genetically
           modified to overproduce proline
    • Authors: Graciele Carraro Balestro; Bruna Higashi; Sheila Mara Sanches Lopes; José Eduardo Gonçalves; Luiz Gonzaga Esteves Vieira; Arildo José Braz de Oliveira; Regina Aparecida Correia Gonçalves
      Pages: 133 - 140
      Abstract: Publication date: April 2017
      Source:Plant Physiology and Biochemistry, Volume 113
      Author(s): Graciele Carraro Balestro, Bruna Higashi, Sheila Mara Sanches Lopes, José Eduardo Gonçalves, Luiz Gonzaga Esteves Vieira, Arildo José Braz de Oliveira, Regina Aparecida Correia Gonçalves
      Global interest in sugarcane has increased significantly in recent years because of its economic impact on sustainable energy production. The purpose of the present study was to evaluate changes in the concentrations of total sugars, amino acids, free proline, and total proteins by colorimetric analyses and nuclear magnetic resonance (NMR) to perform a metabolic profiling of a water-soluble fraction of symplastic sap in response to the constitutive expression of a mutant Δ1-pyrroline-5-carboxylate synthetase (P5CS) gene from Vigna aconitifolia. However, there was not a significant increase in the free proline content in the sap of transgenic plants compared to the non-transformed control plants. The most noticeable difference between the two genotypes was an almost two-fold increase in the accumulation of sucrose in the stem internodes of P5CS transgenic sugarcane plants. The results presented in this work showed that transgenic sugarcane plants with increased levels of free proline accumulates high soluble sugar content and, therefore, may represent a novel genotype for improving sugarcane cultivars.
      Graphical abstract image

      PubDate: 2017-02-18T07:13:24Z
      DOI: 10.1016/j.plaphy.2017.02.010
      Issue No: Vol. 113 (2017)
       
  • A new strategy to enhance the biosynthesis of trans-resveratrol by
           overexpressing stilbene synthase gene in elicited Vitis vinifera cell
           cultures
    • Authors: Mingyu Chu; M.A. Pedreño; Nuria Alburquerque; Lydia Faize; Lorenzo Burgos; Lorena Almagro
      Pages: 141 - 148
      Abstract: Publication date: April 2017
      Source:Plant Physiology and Biochemistry, Volume 113
      Author(s): Mingyu Chu, M.A. Pedreño, Nuria Alburquerque, Lydia Faize, Lorenzo Burgos, Lorena Almagro
      In this work, transgenic lines of suspension cultured cells of Vitis vinifera cv. Monastrell containing the plasmid pMOG800-sts have been obtained. The cell growth of these transgenic cell lines decreased slightly as compared to non-transgenic suspension cultured cells, while cell viability was not affected. In addition, the elicitation with cyclodextrins and methyl jasmonate enhanced the production of trans-resveratrol, observing the highest levels of this compound in sts-expressing transgenic Vitis suspension cultured cells with the sts expression cassette in the forwards orientation. Moreover, the forwards 2 (F2) transgenic cell line produced the greater levels of trans-resveratrol in comparison with the non-transgenic cell line. In fact, when suspension cultured cells were treated with both elicitors, the accumulation of trans-resveratrol outside the cells in the F2 transgenic suspension cultured cells increased twice (1458 mg.L−1) as compared to non-transgenic cell lines (724 mg.L−1). In both cases, the levels of trans-resveratrol detected in the treatment with cyclodextrins and methyl jasmonate were greater than the sum of the individual treatments, and therefore we observed a synergistic effect in the presence of both elicitors. Moreover, the expression profile of sts gene in transgenic V. vinifera cell lines was similar to the expression profile detected for the endogenous sts gene in non-transgenic V. vinifera cell lines, being the expression levels greater in the treatment with methyl jasmonate and cyclodextrins, which was related to the high levels of trans-resveratrol found in the presence of both elicitors.

      PubDate: 2017-02-18T07:13:24Z
      DOI: 10.1016/j.plaphy.2017.02.006
      Issue No: Vol. 113 (2017)
       
  • Lipid signalling mediated by PLD/PA modulates proline and H2O2 levels in
           barley seedlings exposed to short- and long-term chilling stress
    • Authors: Micaela Peppino Margutti; Matias Reyna; María Verónica Meringer; Graciela E. Racagni; Ana Laura Villasuso
      Pages: 149 - 160
      Abstract: Publication date: April 2017
      Source:Plant Physiology and Biochemistry, Volume 113
      Author(s): Micaela Peppino Margutti, Matias Reyna, María Verónica Meringer, Graciela E. Racagni, Ana Laura Villasuso
      Phospholipase D (PLD) hydrolyses phospholipids to yield phosphatidic acid (PA) and a head group, and is involved in responses to a variety of environmental stresses, including chilling and freezing stress. Barley responses to chilling stress (induced by incubating seedlings at 4 °C) are dynamic and the duration of stress, either short (0–180 min) or long-term (24–36 h) had a significant impact on the response. We investigated the roles of PLD/PA in responses of barley (Hordeum vulgare) seedlings to short and long-term chilling stress, based on regulation of proline and reactive oxygen species (ROS) levels. Short-term chilling stress caused rapid and transient increases in PLD activity, proline level, and ROS levels in young leaves. PLD has the ability to catalyse the transphosphatidylation reaction leading to formation of phosphatidylalcohol (preferentially, to PA). Pre-treatment of seedlings with 1-butanol significantly increased proline synthesis but decreased ROS (H2O2) formation. These observations suggest that PLD is a negative regulator of proline synthesis, whereas PA/PLD promote ROS signals. Exogenous PA pre-treatment reduced the proline synthesis but enhanced H2O2 formation. Effects of long-term chilling stress on barley seedlings differed from those of short-term chilling stress. E.g., PLD activity was significantly reduced in young leaves and roots, whereas proline synthesis and ROS signals were increased in roots. Exogenous ROS application enhanced proline level while exogenous proline application reduced ROS level and modulated some effects of long-term chilling stress. Our findings suggest that PLD contributes to signalling pathways in responses to short-term chilling stress in barley seedling, through regulation of the balance between proline and ROS levels. In contrast, reduced PLD activity in the response to long-term chilling stress did not affect proline level. Increased ROS levels may reflect an antioxidant system that is affected by chilling stress and positively compensated by changes in proline level. Implications of our findings are discussed in regard to adaptation strategies of barley seedlings to low temperatures.

      PubDate: 2017-02-18T07:13:24Z
      DOI: 10.1016/j.plaphy.2017.02.008
      Issue No: Vol. 113 (2017)
       
  • Improved tolerance to transplanting injury and chilling stress in rice
           seedlings treated with orysastrobin
    • Authors: Naoto Takahashi; Yukari Sunohara; Masami Fujiwara; Hiroshi Matsumoto
      Pages: 161 - 167
      Abstract: Publication date: April 2017
      Source:Plant Physiology and Biochemistry, Volume 113
      Author(s): Naoto Takahashi, Yukari Sunohara, Masami Fujiwara, Hiroshi Matsumoto
      In addition to their fungicidal activity, strobilurin-type fungicides are reported to show enhancing effects on crop growth and yield. Previous studies suggested that the fungicide has a mitigating effect on abiotic stresses. However, there are few reports about growth enhancement through abiotic stress alleviation by strobilurin-type fungicides, but the mechanism of action of the growth enhancement is still not clear. The present study revealed that orysastrobin enhanced rice seedling growth after root cutting injury and chilling stress. We also found that orysastrobin decreased the transpiration rate and increased ascorbate peroxidase and glutathione reductase activities. This stress alleviation was eliminated by the application of naproxen, a putative abscisic acid biosynthesis inhibitor. These results suggested that orysastrobin improved tolerance against transplanting injury and chilling stress in rice seedlings by inducing water-retaining activity through the suppression of transpiration, and also by inducing reactive oxygen scavenging activity thus inhibiting reactive oxygen species accumulation.

      PubDate: 2017-02-18T07:13:24Z
      DOI: 10.1016/j.plaphy.2017.02.004
      Issue No: Vol. 113 (2017)
       
  • Light intensity dependent photosynthetic electron transport in eelgrass
           (Zostera marina L.)
    • Authors: Xiao Qi Yang; Quan Sheng Zhang; Di Zhang; Zi Tong Sheng
      Pages: 168 - 176
      Abstract: Publication date: April 2017
      Source:Plant Physiology and Biochemistry, Volume 113
      Author(s): Xiao Qi Yang, Quan Sheng Zhang, Di Zhang, Zi Tong Sheng
      Responses of electron transport to three levels of irradiation (20, 200, and 1200 μmol photons m−2 s−1 PAR; exposures called LL, ML and HL, respectively) were investigated in eelgrass (Zostera marina L.) utilizing the chlorophyll a fluorescence technique. Exposure to ML and HL reduced the maximum quantum yield of photosystem II (PSII) (Fv/Fm) and the maximum slope decrease of MR/MRO (V PSI), indicating the occurrence of photoinhibition of both PSII and photosystem I (PSI). A comparatively slow recovery rate of Fv/Fm due to longer half-life recovery time of PSII and 40% lower descending amplitude compared to other higher plants implied the poor resilience of the PSII. Comparatively, PSI demonstrated high resilience and cyclic electron transport (CEF) around PSI maintained high activity. With sustained exposure, the amplitudes of the kinetic components (L 1 and L 2), the probability of electron transfer from PSII to plastoquinone pool (ψ ET2o), and the connectivity among PSII units decreased, accompanied by an enhancement of energy dissipation. Principle component analysis revealed that both V PSI and Fv/Fm contributed to the same component, which was consistent with high connectivity between PSII and PSI, suggesting close coordination between both photosystems. Such coordination was likely beneficial for the adaption of high light. Exposure to LL significantly increased the activity of both PSI and CEF, which could lead to increased light harvesting. Moreover, smooth electron transport as indicated by the enhancement of L 1, L 2, ψ ET2o and the probability of electron transport to the final PSI acceptor sides, could contribute to an increase in light utilization efficiency.

      PubDate: 2017-02-25T08:41:30Z
      DOI: 10.1016/j.plaphy.2017.02.011
      Issue No: Vol. 113 (2017)
       
  • Aldo-keto reductase-1 (AKR1) protect cellular enzymes from salt stress by
           detoxifying reactive cytotoxic compounds
    • Authors: Ramu S. Vemanna; K.C. Babitha; Jayant K. Solanki; V. Amarnatha Reddy; S.K. Sarangi; M. Udayakumar
      Pages: 177 - 186
      Abstract: Publication date: April 2017
      Source:Plant Physiology and Biochemistry, Volume 113
      Author(s): Ramu S. Vemanna, K.C. Babitha, Jayant K. Solanki, V. Amarnatha Reddy, S.K. Sarangi, M. Udayakumar
      Cytotoxic compounds like reactive carbonyl compounds such as methylglyoxal (MG), melandialdehyde (MDA), besides the ROS accumulate significantly at higher levels under salinity stress conditions and affect lipids and proteins that inhibit plant growth and productivity. The detoxification of these cytotoxic compounds by overexpression of NADPH-dependent Aldo-ketoreductase (AKR1) enzyme enhances the salinity stress tolerance in tobacco. The PsAKR1 overexpression plants showed higher survival and chlorophyll content and reduced MDA, H2O2, and MG levels under NaCl stress. The transgenic plants showed reduced levels of Na+ levels in both root and shoot due to reduced reactive carbonyl compounds (RCCs) and showed enhanced membrane stability resulted in higher root growth and biomass. The increased levels of antioxidant glutathione and enhanced activity of superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione reductase (GR) suggest AKR1 could protect these enzymes from the RCC induced protein carbonylation by detoxification process. The transgenics also showed higher activity of delta 1-pyrroline-5- carboxylate synthase (P5CS) enzyme resulted in increasedproline levels to maintain osmotic homeostasis. The results demonstrates that the AKR1 protects proteins or enzymes that are involved in scavenging of cytotoxic compounds by detoxifying RCCs generated under salinity stress.

      PubDate: 2017-02-25T08:41:30Z
      DOI: 10.1016/j.plaphy.2017.02.012
      Issue No: Vol. 113 (2017)
       
  • A ThDREB gene from Tamarix hispida improved the salt and drought tolerance
           of transgenic tobacco and T. hispida
    • Authors: Guiyan Yang; Lili Yu; Kaimin Zhang; Yulin Zhao; Yucong Guo; Caiqiu Gao
      Pages: 187 - 197
      Abstract: Publication date: April 2017
      Source:Plant Physiology and Biochemistry, Volume 113
      Author(s): Guiyan Yang, Lili Yu, Kaimin Zhang, Yulin Zhao, Yucong Guo, Caiqiu Gao
      Dehydration-responsive element-binding (DREB) transcription factors are important abiotic stress tolerance related genes, and some reports on the roles of DREB have primarily addressed herbal plants. To explore the abiotic stress tolerance role of DREB (ThDREB) from Tamarix hispida, a ThDREB gene with a complete ORF of 783 bp that encodes a 28.74 kDa protein with 260 amino acids, was isolated and functionally annotated. ThDREB expression was highly induced by NaCl, PEG, NaHCO3 and CdCl2 treatments, and the highest expression level (369.2-fold of control) was found for the roots that were under NaCl stress for 6 h. The tobacco plants that were transformed by ThDREB were conferred with higher germination rates, fresh weights and root lengths than the wild type (WT) tobacco plants under NaCl and mannitol treatments. The total chlorophyll content (tcc), superoxide dismutase (SOD) and peroxidase (POD) activities were also higher in the transgenic lines in comparison with the WT, and the malondialdehyde (MDA) and H2O2 content, electrolyte leakage (EL) rate and ROS as tracked by staining were generated to a lesser degree in ThDREB transgenic plants than in the WT under NaCl and mannitol stress. Furthermore, the transient overexpression analysis of ThDREB in T. hispida also improved plant salt and drought tolerance in comparison with the empty vector-transformed lines. Our results indicated that ThDREB expression could effectively improve tolerance to salt and drought stress by enhancing the antioxidase activity that keeps the ROS at a low accumulation level and makes them easy to scavenge.

      PubDate: 2017-02-25T08:41:30Z
      DOI: 10.1016/j.plaphy.2017.02.007
      Issue No: Vol. 113 (2017)
       
  • Salt stress reduces kernel number of corn by inhibiting plasma membrane
           H+-ATPase activity
    • Authors: Stephan Jung; Birgit W. Hütsch; Sven Schubert
      Pages: 198 - 207
      Abstract: Publication date: April 2017
      Source:Plant Physiology and Biochemistry, Volume 113
      Author(s): Stephan Jung, Birgit W. Hütsch, Sven Schubert
      Salt stress affects yield formation of corn (Zea mays L.) at various physiological levels resulting in an overall grain yield decrease. In this study we investigated how salt stress affects kernel development of two corn cultivars (cvs. Pioneer 3906 and Fabregas) at and shortly after pollination. In an earlier study, we found an accumulation of hexoses in the kernel tissue. Therefore, it was hypothesized that hexose uptake into developing endosperm and embryo might be inhibited. Hexoses are transported into the developing endosperm by carriers localized in the plasma membrane (PM). The transport is driven by the pH gradient which is built up by the PM H+-ATPase. It was investigated whether the PM H+-ATPase activity in developing corn kernels was inhibited by salt stress, which would cause a lower pH gradient resulting in impaired hexose import and finally in kernel abortion. Corn grown under control and salt stress conditions was harvested 0 and 2 days after pollination (DAP). Under salt stress sucrose and hexose concentrations in kernel tissue were higher 0 and 2 DAP. Kernel PM H+-ATPase activity was not affected at 0 DAP, but it was reduced at 2 DAP. This is in agreement with the finding, that kernel growth and thus kernel setting was not affected in the salt stress treatment at pollination, but it was reduced 2 days later. It is concluded that inhibition of PM H+-ATPase under salt stress impaired the energization of hexose transporters into the cells, resulting in lower kernel growth and finally in kernel abortion.

      PubDate: 2017-02-25T08:41:30Z
      DOI: 10.1016/j.plaphy.2017.02.009
      Issue No: Vol. 113 (2017)
       
  • Simultaneous knock-down of six β-galactosidase genes in petunia petals
           prevents loss of pectic galactan but decreases petal strength
    • Authors: Erin M. O'Donoghue; Sheryl D. Somerfield; Simon C. Deroles; Paul W. Sutherland; Ian C. Hallett; Zoë A. Erridge; David A. Brummell; Donald A. Hunter
      Pages: 208 - 221
      Abstract: Publication date: April 2017
      Source:Plant Physiology and Biochemistry, Volume 113
      Author(s): Erin M. O'Donoghue, Sheryl D. Somerfield, Simon C. Deroles, Paul W. Sutherland, Ian C. Hallett, Zoë A. Erridge, David A. Brummell, Donald A. Hunter
      Galactose (Gal) is incorporated into cell wall polysaccharides as flowers open, but then is lost because of β-galactosidase activity as flowers mature and wilt. The significance of this for flower physiology resides in the role of galactan-containing polysaccharides in the cell wall, which is still largely unresolved. To investigate this, transcript accumulation of six cell wall-associated β-galactosidases was simultaneously knocked down in ‘Mitchell’ petunia (Petunia axillaris x (P. axillaris x P. hybrida)) flower petals. The multi-PhBGAL RNAi construct targeted three bud- and three senescence-associated β-galactosidase genes. The petals of the most down-regulated line (GA19) were significantly disrupted in galactose turnover during flower opening, and at the onset of senescence had retained 86% of their galactose compared with 20% in the controls. The Gal content of Na2CO3-soluble cell wall extracts and the highly insoluble polysaccharides associated with cellulose were particularly affected. Immunodetection with the antibody LM5 showed that much of the cell wall Gal in GA19 was retained as galactan, presumably the side-chains of rhamnogalacturonan-I. The flowers of GA19, despite having retained substantially more galactan, were no different from controls in their internal cell arrangement, dimensions, weight or timing of opening and senescence. However, the GA19 petals had less petal integrity (as judged by force required to cause petal fracture) after opening and showed a greater decline in this integrity with time than controls, raising the possibility that galactan loss is a mechanism for helping to maintain petal tissue cohesion after flower opening.

      PubDate: 2017-03-04T09:07:29Z
      DOI: 10.1016/j.plaphy.2017.02.005
      Issue No: Vol. 113 (2017)
       
  • Evaluation of buffers toxicity in tobacco cells: Homopiperazine-1,4-bis
           (2-ethanesulfonic acid) is a suitable buffer for plant cells studies at
           low pH
    • Authors: Borgo
      Abstract: Publication date: Available online 19 March 2017
      Source:Plant Physiology and Biochemistry
      Author(s): Lucélia Borgo
      Low pH is an important environmental stressor of plant root cells. Understanding the mechanisms of stress and tolerance to acidity is critical; however, there is no widely accepted pH buffer for studies of plant cells at low pH. Such a buffer might also benefit studies of Al toxicity, in which buffering at low pH is also important. The challenge is to find a buffer with minimal cellular effects. We examined the cytotoxicity and possible metabolic disturbances of four buffers that have adequate pKa values and potential use for studies in the pH range of 4.0–5.0. These were homopipes (homopiperazine-1,4-bis (2-ethanesulfonic acid); pKa1 4.4), 3,3-dimethylglutaric acid (pKa1 3.73), β-alanine (pKa1 3.70) and potassium biphthalate (pKa1 2.95; pKa2 5.41). First, tobacco BY-2 cells were grown in a rich medium containing 10 mM of each buffer or MES (2-(N-morpholino) ethanesulfonic acid) as a control, with the pH initially adjusted to 5.7. β-alanine was clearly toxic and dimethylgluturate and biphthalate were found to be cytostatic, in which no culture growth occurred but cell viability was either unaffected or decreased only after 5 days. Only homopipes allowed normal culture growth and cell viability. Homopipes (10 mM) was then tested in cell cultures with an initial pH of 4.3 ± 0.17 in minimal medium to examine whether its undissociated species (H2A) displayed any cellular effects and no cytotoxic effects were observed. It is possible to conclude that among tested buffers, homopipes is the most suitable for studies at low pH, and may be especially useful for aluminum toxicity experiments.

      PubDate: 2017-03-21T19:17:30Z
       
  • Proteomics analysis of maize (Zea mays L.) grain based on iTRAQ reveals
           molecular mechanisms of poor grain filling in inferior grains
    • Authors: Tao Geng; Peng Liu Shuting Dong Jiwang Zhang Bin Zhao
      Abstract: Publication date: Available online 11 March 2017
      Source:Plant Physiology and Biochemistry
      Author(s): Tao Yu, Geng Li, Peng Liu, Shuting Dong, Jiwang Zhang, Bin Zhao
      In maize, inferior grains (IG) located on the upper part of the ear have poor grain filling process compared to superior grains (SG) located on the middle and lower parts of the ear. This difference limits satisfactory yield and quality; however, the underlying molecular mechanisms remain unknown. Here, using the isobaric tag for relative and absolute quantification (iTRAQ) technology, the proteomes of IG and SG during early and middle grain filling stages were investigated. In total, 4720 proteins were identified in maize grain and 305 differentially accumulated proteins (DiAPs) were detected between IG and SG. These DiAPs were involved in diverse cellular and metabolic processes with preferred distribution in protein synthesis/destination and metabolism. Compared to SG, DiAPs related to cell growth/division and starch synthesis were lag-accumulated and down-regulated in IG, respectively, resulting in smaller sink sizes and lower sink activities in IG. Meanwhile, impediment of the glycolysis pathway in IG may lead to reduce energy supply and building materials for substance synthesis. Additionally, reactive oxygen species (ROS) homeostasis and the defense system were disturbed in IG, which might lead to reduce protection against various environmental stresses. The present study provides new information on the proteomic differences between IG and SG, and explains possible molecular mechanisms for poor grain filling in IG.

      PubDate: 2017-03-17T10:05:08Z
       
  • Transcriptional and computational study of expansins differentially
           expressed in response to inclination in radiata pine
    • Authors: Patricio Mateluna; Felipe Valenzuela-Riffo; Luis Morales-Quintana; Raúl Herrera; Patricio Ramos
      Abstract: Publication date: Available online 9 March 2017
      Source:Plant Physiology and Biochemistry
      Author(s): Patricio Mateluna, Felipe Valenzuela-Riffo, Luis Morales-Quintana, Raúl Herrera, Patricio Ramos
      Plants have the ability to reorient their vertical growth when exposed to inclination. This response can be as quick as 2 h in inclined young pine (Pinus radiata D. Don) seedlings, with over accumulation of lignin observed after 9 days s. Several studies have identified expansins involved in cell expansion among other developmental processes in plants. Six putative expansin genes were identified in cDNA libraries isolated from inclined pine stems. A differential transcript abundance was observed by qPCR analysis over a time course of inclination. Five genes changed their transcript accumulation in both stem sides in a spatial and temporal manner compared with non-inclined stem. To compare these expansin genes, and to suggest a possible mechanism of action at molecular level, the structures of the predicted proteins were built by comparative modeling methodology. An open groove on the surface of the proteins composed of conserved residues was observed. Using a cellulose polymer as ligand the protein-ligand interaction was evaluated, with the results showing differences in the protein-ligand interaction mode. Differences in the binding energy interaction can be explained by changes in some residues that generate differences in electrostatic surface in the open groove region, supporting the participation of six members of multifamily proteins in this specific process. The data suggests participation of different expansin proteins in the dissembling and remodeling of the complex cell wall matrix during the reorientation response to inclination.
      Graphical abstract image

      PubDate: 2017-03-10T09:18:47Z
      DOI: 10.1016/j.plaphy.2017.03.005
       
  • In vivo transport of three radioactive [18F]-fluorinated deoxysucrose
           analogs by the maize sucrose transporter ZmSUT1
    • Authors: Thu M. Tran; Carissa S. Hampton; Tom W. Brossard; Michael Harmata; J. David Robertson; Silvia S. Jurisson; David M. Braun
      Abstract: Publication date: Available online 8 March 2017
      Source:Plant Physiology and Biochemistry
      Author(s): Thu M. Tran, Carissa S. Hampton, Tom W. Brossard, Michael Harmata, J. David Robertson, Silvia S. Jurisson, David M. Braun
      Sucrose transporter (SUT) proteins translocate sucrose across cell membranes; however, mechanistic aspects of sucrose binding by SUTs are not well resolved. Specific hydroxyl groups in sucrose participate in hydrogen bonding with SUT proteins. We previously reported that substituting a radioactive fluorine-18 [18F] at the C-6′ position within the fructosyl moiety of sucrose did not affect sucrose transport by the maize (Zea mays) ZmSUT1 protein. To determine how 18F substitution of hydroxyl groups at two other positions within sucrose, the C-1′ in the fructosyl moiety or the C-6 in the glucosyl moiety, impact sucrose transport, we synthesized 1′-[F18]fluoro-1′-deoxysucrose and 6-[F18]fluoro-6-deoxysucrose ([18F]FDS) analogs. Each [18F]FDS derivative was independently introduced into wild-type or sut1 mutant plants, which are defective in sucrose phloem loading. All three (1′-, 6′-, and 6-) [18F]FDS derivatives were efficiently and equally translocated, similarly to carbon-14 [14C]-labeled sucrose. Hence, individually replacing the hydroxyl groups at these positions within sucrose does not interfere with substrate recognition, binding, or membrane transport processes, and hydroxyl groups at these three positions are not essential for hydrogen bonding between sucrose and ZmSUT1. [18F]FDS imaging afforded several advantages compared to [14C]-sucrose detection. We calculated that 1′-[18F]FDS was transported at approximately a rate of 0.90 ± 0.15 m.h-1 in wild-type leaves, and at 0.68 ± 0.25 m.h-1 in sut1 mutant leaves. Collectively, our data indicated that [18F]FDS analogs are valuable tools to probe sucrose-SUT interactions and to monitor sucrose transport in plants.

      PubDate: 2017-03-10T09:18:47Z
      DOI: 10.1016/j.plaphy.2017.03.006
       
  • Nitrogen use strategies of seedlings from neotropical tree species of
           distinct successional groups
    • Authors: Halley Caixeta Oliveira; Ligia Maria Inocêncio da Silva; Letícia Dias de Freitas; Tatiane Viegas Debiasi; Nidia Mara Marchiori; Marcos Pereira Marinho Aidar; Edmilson Bianchini; José Antonio Pimenta; Renata Stolf-Moreira
      Abstract: Publication date: Available online 6 March 2017
      Source:Plant Physiology and Biochemistry
      Author(s): Halley Caixeta Oliveira, Ligia Maria Inocêncio da Silva, Letícia Dias de Freitas, Tatiane Viegas Debiasi, Nidia Mara Marchiori, Marcos Pereira Marinho Aidar, Edmilson Bianchini, José Antonio Pimenta, Renata Stolf-Moreira
      Few studies have analyzed the strategies of neotropical tree seedlings for absorbing, translocating and assimilating the nitrogen. Here, we compared the nitrogen use strategies of seedlings from six tree species that are native to the Brazilian Atlantic Forest and that belong to different successional groups: Trema micrantha, Heliocarpus popayanensis and Cecropia pachystachya (pioneers), Cariniana estrellensis, Eugenia brasiliensis and Guarea kunthiana (non-pioneers). The effects of cultivating seedlings with nitrate or ammonium on the growth, physiology and nitrogen metabolism were analyzed. Nitrate-grown pioneer species had much higher leaf nitrate reductase activity than non-pioneer ones, but non-pioneer seedlings were also able to use nitrate as a nitrogen source. In addition to this remarkable difference between the groups in the capacity for leaf nitrate assimilation, substantial variations in the nitrogen use strategies were observed within the successional classes. Differently from the other non-pioneers, the canopy species C. estrellensis seemed to assimilate nitrate mainly in the leaves. Morphophysiological analyses showed a gradient of ammonium toxicity response, with E. brasiliensis as the most tolerant species, and T. micrantha and H. popayanensis as the most sensitive ones. Guarea kunthiana showed a relatively low tolerance to ammonium and an unusual high translocation of this cation in the xylem sap. In contrast to the other pioneers, C. pachystachya had a high plasticity in the use of nitrogen sources. Overall, these results suggest that nitrogen use strategies of neotropical tree seedlings were not determined solely by their successional position.

      PubDate: 2017-03-10T09:18:47Z
      DOI: 10.1016/j.plaphy.2017.03.003
       
  • Dioscorea alata tuber proteome analysis shows over thirty dioscorin
           isoforms and novel tuber proteins
    • Authors: Shruti Sharma; Ravi Gupta; Renu Deswal
      Abstract: Publication date: Available online 6 March 2017
      Source:Plant Physiology and Biochemistry
      Author(s): Shruti Sharma, Ravi Gupta, Renu Deswal
      In Dioscorea, dioscorin (31 kDa) is the major storage protein constituting 85% of the total tuber proteins. An integrated proteomic and biochemical approach was used to understand the physiological role of dioscorin in the two contrasting growth stages (germinating and mature tuber). HPLC analysis showed 3 fold reduction in mannitol and 12.88 and 1.24 fold increase in sucrose and maltose in the germinating tuber. A 1.8 and 3 fold increase in sucrose phosphate synthase and mannitol dehydrogenase activity respectively was observed in the germinating tuber while a 2 fold higher invertase probably lowers the sucrose accumulation in the mature tuber. SDS-PAGE and 2-D maps of the mature and germinating tubers confirmed depletion (more than 50%) of dioscorin on germination. Dioscorin was purified using ion exchange and gel filtration chromatography with 43.32 fold purification and 38.16 yield. Out of a trail of 35 spots at 31 kDa only 12 spots (identified as dioscorin isoforms) were present in the 2D gel of the purified fraction. To search for other tuber proteins besides dioscorin, the unbound fractions of DEAE column were analysed by 2DGE. DREB 1A, caffeic acid 3-O-methyltransferase and Rab-1 small GTP binding protein were identified perhaps for the first time in the Dioscorea proteome. The interactome analysis revealed these to be involved in oxidative stress, carotenoid synthesis and vesicular transport. This is perhaps the first attempt to identify tuber proteome (although limited) and to understand the physiological significance of these proteins.

      PubDate: 2017-03-10T09:18:47Z
      DOI: 10.1016/j.plaphy.2017.03.001
       
  • TeA is a key virulence factor for Alternaria alternata (Fr.) Keissler
           infection of its host
    • Authors: Ye Kang; Hongwei Feng; Jingxu Zhang; Shiguo Chen; Bernal E. Valverde; Sheng Qiang
      Abstract: Publication date: Available online 4 March 2017
      Source:Plant Physiology and Biochemistry
      Author(s): Ye Kang, Hongwei Feng, Jingxu Zhang, Shiguo Chen, Bernal E. Valverde, Sheng Qiang
      A toxin-deficient mutant strain, HP001 mutant of Alternaria alternata, whose mycelium is unable to infect its host, produces little tenuazonic acid (TeA) toxin. How TeA plays a role in initiating host infection by A. alternata remains unclear. In this research we use Imaging-PAM based on chlorophyll fluorescence parameters and transmission electron microscopy to explore the role of TeA toxin during the infection process of A. alternata. Photosystem II damage began even before wild type mycelium infected the leaves of its host, croftonweed (Ageratina adenophora). Compared with the wild type, HP001 mutant produces morphologically different colonies, hyphae with thinner cell walls, has higher reactive oxygen species (ROS) content and lower peroxidase activity, and fails to form appressoria on the host surface. Adding TeA toxin allows the mutant to partially recover these characters and more closely resemble the wild type. Additionally, we found that the mutant is able to elicit disease symptoms when its mycelium is placed on leaves whose epidermis has been manually removed, which indicates that TeA may be determinant in the fungus recognition of its plant host. Lack of TeA toxin appears responsible for the loss of pathogenicity of the HP001 mutant. As a key virulence factor, TeA toxin not only damages the host plant but also is involved in maintaining ROS content, host recognition, inducing appressoria to infect the host and for allowing completion of the infection process.

      PubDate: 2017-03-10T09:18:47Z
      DOI: 10.1016/j.plaphy.2017.03.002
       
  • A novel Zea mays ssp. mexicana L. MYC-type ICE-like transcription factor
           gene ZmmICE1, enhances freezing tolerance in transgenic Arabidopsis
           thaliana
    • Authors: Xiang Lu; Lei Yang; Mengyuan Yu; Jianbin Lai; Chao Wang; David McNeil; Meixue Zhou; Chengwei Yang
      Abstract: Publication date: Available online 5 February 2017
      Source:Plant Physiology and Biochemistry
      Author(s): Xiang Lu, Lei Yang, Mengyuan Yu, Jianbin Lai, Chao Wang, David McNeil, Meixue Zhou, Chengwei Yang
      The annual Zea mays ssp. mexicana L., a member of the teosinte group, is a close wild relative of maize and thus can be effectively used in maize improvement. In this study, an ICE-like gene, ZmmICE1, was isolated from a cDNA library of RNA-Seq from cold-treated seedling tissues of Zea mays ssp. mexicana L. The deduced protein of ZmmICE1 contains a highly conserved basic helix-loop-helix (bHLH) domain and C-terminal region of ICE-like proteins. The ZmmICE1 protein localizes to the nucleus and shows sumoylation when expressed in an Escherichia coli reconstitution system. In addition, yeast one hybrid assays indicated that ZmmICE1 has transactivation activities. Moreover, ectopic expression of ZmmICE1 in the Arabidopsis ice1-2 mutant increased freezing tolerance. The ZmmICE1 overexpressed plants showed lower electrolyte leakage (EL), reduced contents of malondialdehyde (MDA). The expression of downstream cold related genes of Arabidopsis C-repeat-binding factors (AtCBF1, AtCBF2 and AtCBF3), cold-responsive genes (AtCOR15A and AtCOR47), kinesin-1 member gene (AtKIN1) and responsive to desiccation gene (AtRD29A) was significantly induced when compared with wild type under low temperature treatment. Taken together, these results indicated that ZmmICE1 is the homolog of Arabidopsis inducer of CBF expression genes (AtICE1/2) and plays an important role in the regulation of freezing stress response.

      PubDate: 2017-02-05T11:37:43Z
      DOI: 10.1016/j.plaphy.2017.02.002
       
  • Physiological and biochemical responses to manganese toxicity in ryegrass
           (Lolium perenne L.) genotypes
    • Authors: Claudio Inostroza-Blancheteau; Marjorie Reyes-Díaz; Graciela Berríos; Acácio Rodrigues-Salvador; Adriano Nunes-Nesi; Mariana Deppe; Rolando Demanet; Zed Rengel; Miren Alberdi
      Abstract: Publication date: Available online 3 February 2017
      Source:Plant Physiology and Biochemistry
      Author(s): Claudio Inostroza-Blancheteau, Marjorie Reyes-Díaz, Graciela Berríos, Acácio Rodrigues-Salvador, Adriano Nunes-Nesi, Mariana Deppe, Rolando Demanet, Zed Rengel, Miren Alberdi
      We studied resistance to manganese (Mn) toxicity under acidic conditions and its relationship with nutrients such as calcium (Ca) and magnesium (Mg) in new perennial ryegrass (Lolium perenne L.) genotypes (One-50, Banquet-II and Halo-AR1) introduced in southern Chile, using the Nui genotype as the reference. Plants were grown in nutrient solution at increased Mn concentrations (0–750 μM) at pH 4.8, and physiological and biochemical features were determined. Under higher Mn concentration, the One-50 genotype had a significantly lower relative growth rate (RGR) of shoots and roots, whereas in the other cultivars this parameter did not change under variable Mn treatments. Increasing the Mn concentration led to an increased Mn concentration in roots and shoots, with Banquet-II and Halo-AR1 having higher Mn in roots than shoots. Shoot Mg and Ca concentrations in all genotypes (except Banquet-II) decreased concomitantly with increasing Mn applications. In contrast to the other genotypes, Banquet-II and Halo-AR1 maintained their net CO2 assimilation rate regardless of Mn treatment, whereas the chlorophyll concentration decreased in all genotypes with the exception of Banquet-II. In addition, lipid peroxidation in Banquet-II roots increased at 150 μM Mn, but decreased at higher Mn concentrations. This decrease was associated with an increase in antioxidant capacity as well as total phenol concentration. Banquet-II and Halo-AR1 appear to be the most Mn-resistant genotypes based on RGR and CO2 assimilation rate. In addition, Mn excess provoked a strong decrease in Ca and Mg concentrations in shoots of the Mn-sensitive genotype, whereas only slight variations in the Mn-resistant genotype were noted. When other evaluated parameters were taken into account, we concluded that among the perennial ryegrass genotypes introduced recently into southern Chile Banquet-II appears to be the most Mn-resistant, followed by Halo-AR1, with One-50 being the most sensitive.
      Graphical abstract image

      PubDate: 2017-02-05T11:37:43Z
      DOI: 10.1016/j.plaphy.2017.02.003
       
  • Overexpression of the carbohydrate binding module from Solanum
           lycopersicum expansin 1 (Sl-EXP1) modifies tomato fruit firmness and
           Botrytis cinerea susceptibility
    • Authors: M.A. Perini; I.N. Sin; N.M. Villarreal; M. Marina; A.L.T. Powell; G.A. Martínez; P.M. Civello
      Abstract: Publication date: Available online 2 February 2017
      Source:Plant Physiology and Biochemistry
      Author(s): M.A. Perini, I.N. Sin, N.M. Villarreal, M. Marina, A.L.T. Powell, G.A. Martínez, P.M. Civello
      Firmness, one of the major determinants of postharvest quality and shelf life of fruits is determined by the mechanical resistance imposed by the plant cell wall. Expansins (EXP) are involved in the non-hydrolytic metabolic disassembly of plant cell walls, particularly in processes where relaxation of the wall is necessary, such as fruit development and ripening. As many carbohydrate-associated proteins, expansins have a putative catalytic domain and a carbohydrate-binding module (CBM). Several strategies have been pursued to control the loss of fruit firmness during storage. Most of the approaches have been to suppress the expression of key enzymes involved in the cell wall metabolism, but this is the first time that a CBM was overexpressed in a fruit aimed to control cell wall degradation and fruit softening. We report the constitutive overexpression of the CBM of Solanum lycopersicum expansin 1 (CBM-SlExp1) in the cell wall of tomato plants, and its effects on plant and fruit phenotype. Overexpression of CBM-SlExp1 increased the mechanical resistance of leaves, whereas it did not modify plant growth and general phenotype. However, transgenic plants showed delayed softening and firmer fruits. In addition, fruits were less susceptible to Botrytis cinerea infection, and the “in vitro” growth of the fungus on media containing AIR from the pericarp of transgenic fruits was lower than controls. The possibility of overexpressing a CBM of a fruit-specific expansin to control cell wall degradation and fruit softening is discussed.

      PubDate: 2017-02-05T11:37:43Z
      DOI: 10.1016/j.plaphy.2017.01.029
       
  • Changes in root hydraulic conductivity facilitate the overall hydraulic
           response of rice (Oryza sativa L.) cultivars to salt and osmotic stress
    • Authors: Delong Meng; Wieland Fricke
      Abstract: Publication date: Available online 2 February 2017
      Source:Plant Physiology and Biochemistry
      Author(s): Delong Meng, Wieland Fricke
      The aim of the present work was to assess the significance of changes in root AQP gene expression and hydraulic conductivity (Lp) in the regulation of water balance in two hydroponically-grown rice cultivars (Azucena, Bala) which differ in root morphology, stomatal regulation and aquaporin (AQP) isoform expression. Plants were exposed to NaCl (25 mM, 50 mM) and osmotic stress (5%, 10% PEG6000). Root Lp was determined for exuding root systems (osmotic forces driving water uptake; ‘exudation Lp’) and transpiring plants (hydrostatic forces dominating; ‘transpiration-Lp’). Gene expression was analysed by qPCR. Stress treatments caused a consistent and significant decrease in plant growth, transpirational water loss, stomatal conductance, shoot-to-root surface area ratio and root Lp. Comparison of exudation-with transpiration-Lp supported a significant contribution of AQP-facilitated water flow to root water uptake. Changes in root Lp in response to treatments were correlated much stronger with root morphological characteristics, such as the number of main and lateral roots, surface area ratio of root to shoot and plant transpiration rate than with AQP gene expression. Changes in root Lp, involving AQP function, form an integral part of the plant hydraulic response to stress and facilitate changes in the root-to-shoot surface area ratio, transpiration and stomatal conductance.

      PubDate: 2017-02-05T11:37:43Z
      DOI: 10.1016/j.plaphy.2017.02.001
       
  • Protein tyrosine nitration in plants: Present knowledge, computational
           prediction and future perspectives
    • Authors: Zsuzsanna Kolbert; Gábor Feigl; Ádám Bordé; Árpád Molnár; László Erdei
      Abstract: Publication date: Available online 2 February 2017
      Source:Plant Physiology and Biochemistry
      Author(s): Zsuzsanna Kolbert, Gábor Feigl, Ádám Bordé, Árpád Molnár, László Erdei
      Nitric oxide (NO) and related molecules (reactive nitrogen species) regulate diverse physiological processes mainly through posttranslational modifications such as protein tyrosine nitration (PTN). PTN is a covalent and specific modification of tyrosine (Tyr) residues resulting in altered protein structure and function. In the last decade, great efforts have been made to reveal candidate proteins, target Tyr residues and functional consequences of nitration in plants. This review intends to evaluate the accumulated knowledge about the biochemical mechanism, the structural and functional consequences and the selectivity of plants’ protein nitration and also about the decomposition or conversion of nitrated proteins. At the same time, this review emphasizes yet unanswered or uncertain questions such as the reversibility/irreversibility of tyrosine nitration, the involvement of proteasomes in the removal of nitrated proteins or the effect of nitration on Tyr phosphorylation. The different NO producing systems of algae and higher plants raise the possibility of diversely regulated protein nitration. Therefore studying PTN from an evolutionary point of view would enrich our present understanding with novel aspects. Plant proteomic research can be promoted by the application of computational prediction tools such as GPS-YNO2 and iNitro-Tyr software. Using the reference Arabidopsis proteome,
      Authors performed in silico analysis of tyrosine nitration in order to characterize plant tyrosine nitroproteome. Nevertheless, based on the common results of the present prediction and previous experiments the most likely nitrated proteins were selected thus recommending candidates for detailed future research.

      PubDate: 2017-02-05T11:37:43Z
      DOI: 10.1016/j.plaphy.2017.01.028
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs
Your IP address: 54.167.191.50
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2016