Expression of cadR Enhances its Specific Activity for Cd Detoxification and Accumulation in Arabidopsis
Cadmium (Cd) is a transition metal that is highly toxic in biological systems. Anthropogenic emissions of Cd have increased biogeochemical cycling and the amount of Cd in the biosphere. Here we studied the utility of a bacterial Cd-binding protein, CadR, for the remediation of Cd contamination. CadR was successfully targeted to chloroplasts using a constitutive Cauliflower mosaic virus (CaMV) 35S promoter or a shoot-specific Chl a/b-binding protein 2 gene (CAB2) promoter and an RbcS (small subunit of the Rubisco complex) transit peptide. Under short-term (2 d) exposure to Cd, the cadR transgenic plants showed up to a 2.9-f...
Source: Plant and Cell Physiology - August 1, 2016 Category: Cytology Authors: Li, J., Wei, X., Yu, P., Deng, X., Xu, W., Ma, M., Zhang, H. Tags: Regular Papers Source Type: research
Evolutionary Conservation of Xylan Biosynthetic Genes in Selaginella moellendorffii and Physcomitrella patens
Xylan is a major cross-linking hemicellulose in secondary walls of vascular tissues, and the recruitment of xylan as a secondary wall component was suggested to be a pivotal event for the evolution of vascular tissues. To decipher the evolution of xylan structure and xylan biosynthetic genes, we analyzed xylan substitution patterns and characterized genes mediating methylation of glucuronic acid (GlcA) side chains in xylan of the model seedless vascular plant, Selaginella moellendorffii, and investigated GT43 genes from S. moellendorffii and the model non-vascular plant, Physcomitrella patens, for their roles in xylan bios...
Source: Plant and Cell Physiology - August 1, 2016 Category: Cytology Authors: Haghighat, M., Teng, Q., Zhong, R., Ye, Z.-H. Tags: Regular Papers Source Type: research
HSI2 Repressor Recruits MED13 and HDA6 to Down-Regulate Seed Maturation Gene Expression Directly During Arabidopsis Early Seedling Growth
Arabidopsis HSI2 (HIGH-LEVEL EXPRESSION OF SUGAR-INDUCIBLE GENE 2) which carries a EAR (ERF-associated amphiphilic repression) motif acts as a repressor of seed maturation genes and lipid biosynthesis, whereas MEDIATOR (MED) is a conserved multiprotein complex linking DNA-bound transcription factors to RNA polymerase II transcription machinery. How HSI2 executes its repressive function through MED is hitherto unknown. Here, we show that HSI2 and its homolog, HSI2-lik (HSL1), are able to form homo- and heterocomplexes. Both factors bind to the TRAP240 domain of MED13, a subunit of the MED CDK8 module. Mutant alleles of the ...
Source: Plant and Cell Physiology - August 1, 2016 Category: Cytology Authors: Chhun, T., Chong, S. Y., Park, B. S., Wong, E. C. C., Yin, J.-L., Kim, M., Chua, N.-H. Tags: Regular Papers Source Type: research
Functional Analysis of Amorpha-4,11-Diene Synthase (ADS) Homologs from Non-Artemisinin-Producing Artemisia Species: The Discovery of Novel Koidzumiol and (+)-{alpha}-Bisabolol Synthases
In this study, we examined genes highly homologous to ADS, the first committed gene in the pathway, in 13 Artemisia species. We detected ADS homologs in A. absinthium, A. kurramensis and A. maritima. We analyzed the enzymatic functions of all of the ADS homologs after obtaining their cDNA. We found that the ADS homolog from A. absinthium exhibited novel activity in the cyclization of farnesyl pyrophosphate (FPP) to koidzumiol, a rare natural sesquiterpenoid. Those from A. kurramensis and A. maritima showed similar, but novel, activities in the cyclization of FPP to (+)-α-bisabolol. The unique functions of the novel s...
Source: Plant and Cell Physiology - August 1, 2016 Category: Cytology Authors: Muangphrom, P., Seki, H., Suzuki, M., Komori, A., Nishiwaki, M., Mikawa, R., Fukushima, E. O., Muranaka, T. Tags: Regular Papers Source Type: research
Genome-Wide Identification and Analysis of the MYB Transcription Factor Superfamily in Solanum lycopersicum
MYB proteins constitute one of the largest transcription factor families in the plant kingdom, members of which perform a variety of functions in plant biological processes. However, there are only very limited reports on the characterization of MYB transcription factors in tomato (Solanum lycopersicum). In our study, a total of 127 MYB genes have been identified in the tomato genome. A complete overview of these MYB genes is presented, including the phylogeny, gene structures, protein motifs, chromosome locations and expression patterns. The 127 SlMYB proteins could be classified into 18 subgroups based on domain similari...
Source: Plant and Cell Physiology - August 1, 2016 Category: Cytology Authors: Li, Z., Peng, R., Tian, Y., Han, H., Xu, J., Yao, Q. Tags: Regular Papers Source Type: research
Heterodimer Formation of BnPKSA or BnPKSB with BnACOS5 Constitutes a Multienzyme Complex in Tapetal Cells and is Involved in Male Reproductive Development in Brassica napus
Multienzyme associations localized to specific subcellular sites are involved in several critical functions in cellular metabolism, such as plant survival and reproduction. To date, few multienzyme complexes involved in male fertility have been examined in Brassica napus. Here, we reported that in B. napus, the members of a multienzyme complex work in an interaction pattern different from that in Arabidopsis thaliana for sporopollenin biosynthesis. 7365A, a male-sterile mutant with a relatively smooth anther cuticle, was found to have a dramatic reduction in both cutin monomers and wax composition. Proteomic comparison bet...
Source: Plant and Cell Physiology - August 1, 2016 Category: Cytology Authors: Qin, M., Tian, T., Xia, S., Wang, Z., Song, L., Yi, B., Wen, J., Shen, J., Ma, C., Fu, T., Tu, J. Tags: Regular Papers Source Type: research
The Cotton Mitogen-Activated Protein Kinase Kinase 3 Functions in Drought Tolerance by Regulating Stomatal Responses and Root Growth
Mitogen-activated protein kinase (MAPK) cascades play critical roles in signal transduction processes in eukaryotes. The MAPK kinases (MAPKKs) that link MAPKK kinases (MAPKKKs) and MAPKs are key components of MAPK cascades. However, the intricate regulatory mechanisms that control MAPKKs under drought stress conditions are not fully understood, especially in cotton (Gossypium hirsutum). Here, we isolated and characterized the cotton group B MAPKK gene GhMKK3. Overexpressing GhMKK3 in Nicotiana benthamiana enhanced tolerance to drought, and the results of RNA sequencing (RNA-seq) and quantitative real-time PCR (qRT-PCR) ass...
Source: Plant and Cell Physiology - August 1, 2016 Category: Cytology Authors: Wang, C., Lu, W., He, X., Wang, F., Zhou, Y., Guo, X., Guo, X. Tags: Regular Papers Source Type: research
N-Glycomic and Microscopic Subcellular Localization Analyses of NPP1, 2 and 6 Strongly Indicate that trans-Golgi Compartments Participate in the Golgi to Plastid Traffic of Nucleotide Pyrophosphatase/Phosphodiesterases in Rice
Nucleotide pyrophosphatase/phosphodiesterases (NPPs) are widely distributed N-glycosylated enzymes that catalyze the hydrolytic breakdown of numerous nucleotides and nucleotide sugars. In many plant species, NPPs are encoded by a small multigene family, which in rice are referred to NPP1–NPP6. Although recent investigations showed that N-glycosylated NPP1 is transported from the endoplasmic reticulum (ER)–Golgi system to the chloroplast through the secretory pathway in rice cells, information on N-glycan composition and subcellular localization of other NPPs is still lacking. Computer-assisted analyses of the a...
Source: Plant and Cell Physiology - August 1, 2016 Category: Cytology Authors: Kaneko, K., Takamatsu, T., Inomata, T., Oikawa, K., Itoh, K., Hirose, K., Amano, M., Nishimura, S.-I., Toyooka, K., Matsuoka, K., Pozueta-Romero, J., Mitsui, T. Tags: Regular Papers Source Type: research
Ectopic Expression of DREB Transcription Factor, AtDREB1A, Confers Tolerance to Drought in Transgenic Salvia miltiorrhiza
Drought decreases crop productivity more than any other type of environmental stress. Transcription factors (TFs) play crucial roles in regulating plant abiotic stress responses. The Arabidopsis thaliana gene DREB1A/CBF3, encoding a stress-inducible TF, was introduced into Salvia miltiorrhiza. Ectopic expression of AtDREB1A resulted in increased drought tolerance, and transgenic lines had higher relative water content and Chl content, and exhibited an increased photosynthetic rate when subjected to drought stress. AtDREB1A transgenic plants generally displayed lower malondialdehyde (MDA), but higher superoxide dismutase (S...
Source: Plant and Cell Physiology - August 1, 2016 Category: Cytology Authors: Wei, T., Deng, K., Liu, D., Gao, Y., Liu, Y., Yang, M., Zhang, L., Zheng, X., Wang, C., Song, W., Chen, C., Zhang, Y. Tags: Regular Papers Source Type: research
The SAC51 Family Plays a Central Role in Thermospermine Responses in Arabidopsis
The acaulis5 (acl5) mutant of Arabidopsis thaliana is defective in the biosynthesis of thermospermine and shows a dwarf phenotype associated with excess xylem differentiation. SAC51 was identified from a dominant suppressor of acl5, sac51-d, and encodes a basic helix–loop–helix protein. The sac51-d mutant has a premature termination codon in an upstream open reading frame (uORF) that is conserved among all four members of the SAC51 family, SAC51 and SACL1–SACL3. This suggests that thermospermine cancels the inhibitory effect of the uORF in main ORF translation. Another suppressor, sac57-d, has a mutation ...
Source: Plant and Cell Physiology - August 1, 2016 Category: Cytology Authors: Cai, Q., Fukushima, H., Yamamoto, M., Ishii, N., Sakamoto, T., Kurata, T., Motose, H., Takahashi, T. Tags: Rapid Paper Source Type: research
Interaction Between ABA Signaling and Copper Homeostasis in Arabidopsis thaliana
ABA is involved in plant responses to non-optimal environmental conditions, including nutrient availability. Since copper (Cu) is a very important micronutrient, unraveling how ABA affects Cu uptake and distribution is relevant to ensure adequate Cu nutrition in plants subjected to stress conditions. Inversely, knowledge about how the plant nutritional status can interfere with ABA biosynthesis and signaling mechanisms is necessary to optimize stress tolerance in horticultural crops. Here the reciprocal influence between ABA and Cu content was addressed by using knockout mutants and overexpressing transgenic plants of high...
Source: Plant and Cell Physiology - July 7, 2016 Category: Cytology Authors: Carrio-Segui, A., Romero, P., Sanz, A., Penarrubia, L. Tags: Regular Papers Source Type: research
Regulation and Levels of the Thylakoid K+/H+ Antiporter KEA3 Shape the Dynamic Response of Photosynthesis in Fluctuating Light
Crop canopies create environments of highly fluctuating light intensities. In such environments, photoprotective mechanisms and their relaxation kinetics have been hypothesized to limit photosynthetic efficiency and therefore crop yield potential. Here, we show that overexpression of the Arabidopsis thylakoid K+/H+ antiporter KEA3 accelerates the relaxation of photoprotective energy-dependent quenching after transitions from high to low light in Arabidopsis and tobacco. This, in turn, enhances PSII quantum efficiency in both organisms, supporting that in wild-type plants, residual light energy quenching following a high to...
Source: Plant and Cell Physiology - July 7, 2016 Category: Cytology Authors: Armbruster, U., Leonelli, L., Correa Galvis, V., Strand, D., Quinn, E. H., Jonikas, M. C., Niyogi, K. K. Tags: Regular Papers Source Type: research
Concerted Changes in the Phosphoproteome and Metabolome Under Different CO2/O2 Gaseous Conditions in Arabidopsis Rosettes
Considerable efforts are currently devoted to understanding the regulation of primary carbon metabolism in plant leaves, which is known to change dramatically with environmental conditions, e.g. during light/dark transitions. Protein phosphorylation is believed to be a key factor in such a metabolic control. In fact, some studies have suggested modifications in the phosphorylation status of key enzymes in the dark compared with the light, or when photosynthesis varies. However, a general view of the phosphoproteome and reciprocal alterations in both the phosphoproteome and metabolome under a wide spectrum of CO2 and O2 con...
Source: Plant and Cell Physiology - July 7, 2016 Category: Cytology Authors: Abadie, C., Mainguet, S., Davanture, M., Hodges, M., Zivy, M., Tcherkez, G. Tags: Regular Papers Source Type: research
OsCHX14 is Involved in the K+ Homeostasis in Rice (Oryza sativa) Flowers
Previously we showed in the osjar1 mutants that the lodicule senescence which controls the closing of rice flowers was delayed. This resulted in florets staying open longer when compared with the wild type. The gene OsJAR1 is silenced in osjar1 mutants and is a key member of the jasmonic acid (JA) signaling pathway. We found that K concentrations in lodicules and flowers of osjar1-2 were significantly elevated compared with the wild type, indicating that K+ homeostasis may play a role in regulating the closure of rice flowers. The cation/H+ exchanger (CHX) family from rice was screened for potential K+ transporters involve...
Source: Plant and Cell Physiology - July 7, 2016 Category: Cytology Authors: Chen, Y., Ma, J., Miller, A. J., Luo, B., Wang, M., Zhu, Z., Ouwerkerk, P. B. F. Tags: Regular Papers Source Type: research
Photoprotection vs. Photoinhibition of Photosystem II in Transplastomic Lettuce (Lactuca sativa) Dominantly Accumulating Astaxanthin
In this study, we evaluated the activity and assembly of PSII in CGM lettuce. The maximum quantum yield of PSII in CGM lettuce was <0.6; however, the quantum yield of PSII was comparable with that in control leaves under higher light intensity. CGM lettuce showed a lower ability to induce non-photochemical quenching (NPQ) than the control under various light intensities. The fraction of slowly recovering NPQ in CGM lettuce, which is considered to be photoinhibitory quenching (qI), was less than half that of the control. In fact, 1O2 generation was lower in CGM than in control leaves under high light intensity. CGM lettu...
Source: Plant and Cell Physiology - July 7, 2016 Category: Cytology Authors: Fujii, R., Yamano, N., Hashimoto, H., Misawa, N., Ifuku, K. Tags: Special Focus Issue - Regular Papers Source Type: research
