Overexpressed Superoxide Dismutase and Catalase Act Synergistically to Protect the Repair of PSII during Photoinhibition in Synechococcus elongatus PCC 7942
The repair of PSII under strong light is particularly sensitive to reactive oxygen species (ROS), such as the superoxide radical and hydrogen peroxide, and these ROS are efficiently scavenged by superoxide dismutase (SOD) and catalase. In the present study, we generated transformants of the cyanobacterium Synechococcus elongatus PCC 7942 that overexpressed an iron superoxide dismutase (Fe-SOD) from Synechocystis sp. PCC 6803; a highly active catalase (VktA) from Vibrio rumoiensis; and both enzymes together. Then we examined the sensitivity of PSII to photoinhibition in the three strains. In cells that overexpressed either ...
Source: Plant and Cell Physiology - September 7, 2016 Category: Cytology Authors: Sae-Tang, P., Hihara, Y., Yumoto, I., Orikasa, Y., Okuyama, H., Nishiyama, Y. Tags: Regular Papers Source Type: research
Impact of Sulfur Starvation in Autotrophic and Heterotrophic Cultures of the Extremophilic Microalga Galdieria phlegrea (Cyanidiophyceae)
This study reports the effects of S deprivation in autotrophic and heterotrophic cultures of Galdieria phlegrea (Cyanidiophyceae), a unicellular red alga isolated in the Solfatara crater located in Campi Flegrei (Naples, Italy), where H2S is the prevalent form of gaseous S in the fumarolic fluids and S is widespread in the soils near the fumaroles. This is the first report on the effects of S deprivation on a sulfurous microalga that is also able to grow heterotrophically in the dark. The removal of S from the culture medium of illuminated cells caused a decrease in the soluble protein content and a significant decrease in...
Source: Plant and Cell Physiology - September 7, 2016 Category: Cytology Authors: Carfagna, S., Bottone, C., Cataletto, P. R., Petriccione, M., Pinto, G., Salbitani, G., Vona, V., Pollio, A., Ciniglia, C. Tags: Regular Papers Source Type: research
Role of Transcription Factor HAT1 in Modulating Arabidopsis thaliana Response to Cucumber mosaic virus
Arabidopsis thaliana homeodomain-leucine zipper protein 1 (HAT1) belongs to the homeodomain-leucine zipper (HD-Zip) family class II that plays important roles in plant growth and development as a transcription factor. To elucidate further the role of HD-Zip II transcription factors in plant defense, the A. thaliana hat1, hat1hat3 and hat1hat2hat3 mutants and HAT1 overexpression plants (HAT1OX) were challenged with Cucumber mosaic virus (CMV). HAT1OX displayed more susceptibility, while loss-of-function mutants of HAT1 exhibited less susceptibility to CMV infection. HAT1 and its close homologs HAT2 and HAT3 function redunda...
Source: Plant and Cell Physiology - September 7, 2016 Category: Cytology Authors: Zou, L.-J., Deng, X.-G., Han, X.-Y., Tan, W.-R., Zhu, L.-J., Xi, D.-H., Zhang, D.-W., Lin, H.-H. Tags: Regular Papers Source Type: research
The miR396b of Poncirus trifoliata Functions in Cold Tolerance by Regulating ACC Oxidase Gene Expression and Modulating Ethylene-Polyamine Homeostasis
MicroRNAs (miRNAs) are non-coding regulatory molecules that play important roles in a variety of biological processes. Although a number of cold-responsive miRNAs have been computationally identified, functions and mechanisms of most miRNAs are not well understood. Herein, the function of trifoliate orange [Poncirus trifoliata (L.) Raf.] miRNA396b (ptr-miR396b) in cold tolerance and its potential regulatory module were investigated. Compared with the wild type (WT), transgenic lemon (Citrus limon) plants overexpressing ptr-MIR396b, the precursor of ptr-miR396b, displayed enhanced cold tolerance. Ptr-miR396b was experimenta...
Source: Plant and Cell Physiology - September 7, 2016 Category: Cytology Authors: Zhang, X., Wang, W., Wang, M., Zhang, H.-Y., Liu, J.-H. Tags: Regular Papers Source Type: research
Modulation of Plant RAB GTPase-Mediated Membrane Trafficking Pathway at the Interface Between Plants and Obligate Biotrophic Pathogens
RAB5 is a small GTPase that acts in endosomal trafficking. In addition to canonical RAB5 members that are homologous to animal RAB5, land plants harbor a plant-specific RAB5, the ARA6 group, which regulates trafficking events distinct from canonical RAB5 GTPases. Here, we report that plant RAB5, both canonical and plant-specific members, accumulate at the interface between host plants and biotrophic fungal and oomycete pathogens. Biotrophic fungi and oomycetes colonize living plant tissues by establishing specialized infection hyphae, the haustorium, within host plant cells. We found that Arabidopsis thaliana ARA6/RABF1, a...
Source: Plant and Cell Physiology - September 7, 2016 Category: Cytology Authors: Inada, N., Betsuyaku, S., Shimada, T. L., Ebine, K., Ito, E., Kutsuna, N., Hasezawa, S., Takano, Y., Fukuda, H., Nakano, A., Ueda, T. Tags: Regular Papers Source Type: research
Response and Defense Mechanisms of Taxus chinensis Leaves Under UV-A Radiation are Revealed Using Comparative Proteomics and Metabolomics Analyses
Taxus chinensis var. mairei is a species endemic to south-eastern China and one of the natural sources for the anticancer medicine paclitaxel. To investigate the molecular response and defense mechanisms of T. chinensis leaves to enhanced ultraviolet-A (UV-A) radiation, gel-free/label-free and gel-based proteomics and gas chromatography–mass spectrometry (GC-MS) analyses were performed. The transmission electron microscopy results indicated damage to the chloroplast under UV-A radiation. Proteomics analyses in leaves and chloroplasts showed that photosynthesis-, glycolysis-, secondary metabolism-, stress-, and protei...
Source: Plant and Cell Physiology - September 7, 2016 Category: Cytology Authors: Zheng, W., Komatsu, S., Zhu, W., Zhang, L., Li, X., Cui, L., Tian, J. Tags: Regular Papers Source Type: research
Hd18, Encoding Histone Acetylase Related to Arabidopsis FLOWERING LOCUS D, is Involved in the Control of Flowering Time in Rice
Flowering time is one of the most important agronomic traits in rice (Oryza sativa L.), because it defines harvest seasons and cultivation areas, and affects yields. We used a map-based strategy to clone Heading date 18 (Hd18). The difference in flowering time between the Japanese rice cultivars Koshihikari and Hayamasari was due to a single nucleotide polymorphism within the Hd18 gene, which encodes an amine oxidase domain-containing protein and is homologous to Arabidopsis FLOWERING LOCUS D (FLD). The Hayamasari Hd18 allele and knockdown of Hd18 gene expression delayed the flowering time of rice plants regardless of the ...
Source: Plant and Cell Physiology - September 7, 2016 Category: Cytology Authors: Shibaya, T., Hori, K., Ogiso-Tanaka, E., Yamanouchi, U., Shu, K., Kitazawa, N., Shomura, A., Ando, T., Ebana, K., Wu, J., Yamazaki, T., Yano, M. Tags: Regular Papers Source Type: research
Overexpression of OsMYC2 Results in the Up-Regulation of Early JA-Rresponsive Genes and Bacterial Blight Resistance in Rice
JASMONATE ZIM-domain (JAZ) proteins act as transcriptional repressors of jasmonic acid (JA) responses and play a crucial role in the regulation of host immunity in plants. Here, we report that OsMYC2, a JAZ-interacting transcription factor in rice (Oryza sativa L.), plays an important role in the resistance response against rice bacterial blight, which is one of the most serious diseases in rice, caused by Xanthomonas oryzae pv. oryzae (Xoo). The results showed that OsMYC2 interacted with some OsJAZ proteins in a JAZ-interacting domain (JID)-dependent manner. The up-regulation of OsMYC2 in response to JA was regulated by O...
Source: Plant and Cell Physiology - September 7, 2016 Category: Cytology Authors: Uji, Y., Taniguchi, S., Tamaoki, D., Shishido, H., Akimitsu, K., Gomi, K. Tags: Regular Papers Source Type: research
The Arabidopsis Iron-Sulfur Protein GRXS17 is a Target of the Ubiquitin E3 Ligases RGLG3 and RGLG4
The stability of signaling proteins in eukaryotes is often controlled by post-translational modifiers. For polyubiquitination, specificity is assured by E3 ubiquitin ligases. Although plant genomes encode hundreds of E3 ligases, only few targets are known, even in the model Arabidopsis thaliana. Here, we identified the monothiol glutaredoxin GRXS17 as a substrate of the Arabidopsis E3 ubiquitin ligases RING DOMAIN LIGASE 3 (RGLG3) and RGLG4 using a substrate trapping approach involving tandem affinity purification of RING-dead versions. Simultaneously, we used a ubiquitin-conjugating enzym (UBC) panel screen to pinpoint UB...
Source: Plant and Cell Physiology - September 7, 2016 Category: Cytology Authors: Nagels Durand, A., Inigo, S., Ritter, A., Iniesto, E., De Clercq, R., Staes, A., Van Leene, J., Rubio, V., Gevaert, K., De Jaeger, G., Pauwels, L., Goossens, A. Tags: Rapid Paper Source Type: research
Effector-Triggered Immunity Determines Host Genotype-Specific Incompatibility in Legume-Rhizobium Symbiosis
This study revealed a common molecular mechanism underlying both plant–pathogen and plant–symbiont interactions, and suggests that establishment of a root nodule symbiosis requires the evasion or suppression of plant immune responses triggered by rhizobial effectors. (Source: Plant and Cell Physiology)
Source: Plant and Cell Physiology - August 1, 2016 Category: Cytology Authors: Yasuda, M., Miwa, H., Masuda, S., Takebayashi, Y., Sakakibara, H., Okazaki, S. Tags: Regular Papers Source Type: research
Involvement of OST1 Protein Kinase and PYR/PYL/RCAR Receptors in Methyl Jasmonate-Induced Stomatal Closure in Arabidopsis Guard Cells
Methyl jasmonate (MeJA) induces stomatal closure. It has been shown that stomata of many ABA-insensitive mutants are also insensitive to MeJA, and a low amount of ABA is a prerequisite for the MeJA response. However, the molecular mechanisms of the interaction between ABA and MeJA signaling remain to be elucidated. Here we studied the interplay of signaling of the two hormones in guard cells using the quadruple ABA receptor mutant pyr1 pyl1 pyl2 pyl4 and ABA-activated protein kinase mutants ost1-2 and srk2e. In the quadruple mutant, MeJA-induced stomatal closure, H2O2 production, nitric oxide (NO) production, cytosolic alk...
Source: Plant and Cell Physiology - August 1, 2016 Category: Cytology Authors: Yin, Y., Adachi, Y., Nakamura, Y., Munemasa, S., Mori, I. C., Murata, Y. Tags: Regular Papers Source Type: research
Characterization of the AtSPX3 Promoter Elucidates its Complex Regulation in Response to Phosphorus Deficiency
AtSPX3, responding to phosphate (Pi) deficiency by its expression, is an important gene involved in Pi homeostasis in Arabidopsis. To understand its transcriptional regulation, we characterized the AtSPX3 promoter by distal truncation, internal deletion and mutation of the predicted cis-elements, and identified multiple cis-elements responsive to Pi status. The P1BS (AtPHR-binding site) and AtMyb4 (putative MYB4-binding site) elements were two main cis-elements in the AtSPX3 promoter. P1BS is essential and has a dosage effect for activating expression of the gene under Pi deficiency, while the element AtMyb4 possesses a du...
Source: Plant and Cell Physiology - August 1, 2016 Category: Cytology Authors: Li, Y., Wu, H., Fan, H., Zhao, T., Ling, H.-Q. Tags: Regular Papers Source Type: research
Carbon Isotope Composition of Carbohydrates and Polyols in Leaf and Phloem Sap of Phaseolus vulgaris L. Influences Predictions of Plant Water Use Efficiency
The use of carbon isotope abundance (13C) to assess plant carbon acquisition and water use has significant potential for use in crop management and plant improvement programs. Utilizing Phaseolus vulgaris L. as a model system, this study demonstrates the occurrence and sensitivity of carbon isotope fractionation during the onset of abiotic stresses between leaf and phloem carbon pools. In addition to gas exchange data, compound-specific measures of carbon isotope abundance and concentrations of soluble components of phloem sap were compared with major carbohydrate and sugar alcohol pools in leaf tissue. Differences in both...
Source: Plant and Cell Physiology - August 1, 2016 Category: Cytology Authors: Smith, M., Wild, B., Richter, A., Simonin, K., Merchant, A. Tags: Regular Papers Source Type: research
Identification of Phosphoinositide-Binding Protein PATELLIN2 as a Substrate of Arabidopsis MPK4 MAP Kinase during Septum Formation in Cytokinesis
The phosphorylation of proteins by protein kinases controls many cellular and physiological processes, which include intracellular signal transduction. However, the underlying molecular mechanisms of such controls and numerous substrates of protein kinases remain to be characterized. The mitogen-activated protein kinase (MAPK) cascade is of particular importance in a variety of extracellular and intracellular signaling processes. In plant cells, the progression of cytokinesis is an excellent example of an intracellular phenomenon that requires the MAPK cascade. However, the way in which MAPKs control downstream processes d...
Source: Plant and Cell Physiology - August 1, 2016 Category: Cytology Authors: Suzuki, T., Matsushima, C., Nishimura, S., Higashiyama, T., Sasabe, M., Machida, Y. Tags: Regular Papers Source Type: research
Myosin XI-I is Mechanically and Enzymatically Unique Among Class-XI Myosins in Arabidopsis
Arabidopsis possesses 13 genes encoding class-XI myosins. Among these, myosin XI-I is phylogenetically distant. To examine the molecular properties of Arabidopsis thaliana myosin XI-I (At myosin XI-I), we performed in vitro mechanical and enzymatic analyses using recombinant constructs of At myosin XI-I. Unlike other biochemically studied class-XI myosins, At myosin XI-I showed extremely low actin-activated ATPase activity (Vmax = 3.7 Pi s–1 head–1). The actin-sliding velocity of At myosin XI-I was 0.25 µm s–1, >10 times lower than those of other class-XI myosins. The ADP dissociation rate from a...
Source: Plant and Cell Physiology - August 1, 2016 Category: Cytology Authors: Haraguchi, T., Tominaga, M., Nakano, A., Yamamoto, K., Ito, K. Tags: Regular Papers Source Type: research
