Differential Cellular Control by Cotyledon-Derived Phytohormones Involved in Graft Reunion of Arabidopsis Hypocotyls
In this study, we performed morphological and gene expression analyses of graft union in Arabidopsis hypocotyl. We found that removal of the cotyledon and treatment of the cotyledon with the auxin transport inhibitor triiodobenzoic acid (TIBA) suppressed cell proliferation of vascular tissue during graft union formation. These treatments also suppressed expression of IAA5, ANAC071, ANAC096 and CYCB1;1. ANAC071 is involved in the tissue reunion process. The anac071 anac096 double mutant suppressed cell proliferation more so than either of the single mutants. On the other hand, paclobutrazol treatment or deficiency of gibber...
Source: Plant and Cell Physiology - December 15, 2016 Category: Cytology Authors: Matsuoka, K., Sugawara, E., Aoki, R., Takuma, K., Terao-Morita, M., Satoh, S., Asahina, M. Tags: Regular Papers Source Type: research
CCX1, a Putative Cation/Ca2+ Exchanger, Participates in Regulation of Reactive Oxygen Species Homeostasis and Leaf Senescence
The major developmental significance of leaf senescence is the massive recycling of nutrients from senescing leaves to nascent organs, including seeds, to meet the requirement of their rapid development, so-called nutrient remobilization. The efficiency of nutrient remobilization is associated with the activity of diverse transporters. A large number of transporters are up-regulated during leaf senescence in Arabidopsis, many of which participate in regulating leaf senescence via different signaling pathways. Here, we report that a member of the cation/Ca2+ exchanger family, CCX1, is highly induced during leaf senescence i...
Source: Plant and Cell Physiology - December 15, 2016 Category: Cytology Authors: Li, Z., Wang, X., Chen, J., Gao, J., Zhou, X., Kuai, B. Tags: Regular Papers Source Type: research
Efficient and Heritable Targeted Mutagenesis in Mosses Using the CRISPR/Cas9 System
Targeted genome modification by RNA-guided nucleases derived from the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated nuclease 9 (Cas9) system has seen rapid development in many organisms, including several plant species. In the present study, we succeeded in introducing the CRISPR/Cas9 system into the non-model organism Scopelophila cataractae, a moss that exhibits heavy metal tolerance, and the model organism Physcomitrella patens. Utilizing the process by which moss plants regenerate from protoplasts, we conducted targeted mutagenesis by expression of single-chain guide RNA (sgRNA) an...
Source: Plant and Cell Physiology - December 15, 2016 Category: Cytology Authors: Nomura, T., Sakurai, T., Osakabe, Y., Osakabe, K., Sakakibara, H. Tags: Regular Papers Source Type: research
DELAYED GREENING 238, a Nuclear-Encoded Chloroplast Nucleoid Protein, Is Involved in the Regulation of Early Chloroplast Development and Plastid Gene Expression in Arabidopsis thaliana
Chloroplast development is an essential process for plant growth that is regulated by numerous proteins. Plastid-encoded plastid RNA polymerase (PEP) is a large complex that regulates plastid gene transcription and chloroplast development. However, many proteins in this complex remain to be identified. Here, through large-scale screening of Arabidopsis mutants by Chl fluorescence imaging, we identified a novel protein, DELAYED GREENING 238 (DG238), which is involved in regulating chloroplast development and plastid gene expression. Loss of DG238 retards plant growth, delays young leaf greening, affects chloroplast developm...
Source: Plant and Cell Physiology - December 15, 2016 Category: Cytology Authors: Wang, M., Jiang, L., Da, Q., Liu, J., Feng, D., Wang, J., Wang, H.-B., Jin, H.-L. Tags: Regular Papers Source Type: research
Transgenic Tobacco Lines Expressing Sense or Antisense FERROCHELATASE 1 RNA Show Modified Ferrochelatase Activity in Roots and Provide Experimental Evidence for Dual Localization of Ferrochelatase 1
In plants, two genes encode ferrochelatase (FC), which catalyzes iron chelation into protoporphyrin IX at the final step of heme biosynthesis. FERROCHELATASE1 (FC1) is continuously, but weakly expressed in roots and leaves, while FC2 is dominantly active in leaves. As a continuation of previous studies on the physiological consequences of FC2 inactivation in tobacco, we aimed to assign FC1 function in plant organs. While reduced FC2 expression leads to protoporphyrin IX accumulation in leaves, FC1 down-regulation and overproduction caused reduced and elevated FC activity in root tissue, respectively, but were not associate...
Source: Plant and Cell Physiology - December 15, 2016 Category: Cytology Authors: Hey, D., Ortega-Rodes, P., Fan, T., Schnurrer, F., Brings, L., Hedtke, B., Grimm, B. Tags: Regular Papers Source Type: research
Clade IVa Basic Helix-Loop-Helix Transcription Factors Form Part of a Conserved Jasmonate Signaling Circuit for the Regulation of Bioactive Plant Terpenoid Biosynthesis
In this study, we report that promoters of the genes encoding the enzymes involved in the specific terpenoid pathway of one of these species can be transactivated by the orthologous bHLH factor from the other species through recognition of the same cis-regulatory elements. Accordingly, ectopic expression of CrBIS1 in M. truncatula hairy roots up-regulated the expression of all genes required for soyasaponin production, resulting in strongly increased levels of soyasaponins in the transformed roots. Likewise, transient expression of MtTSAR1 and MtTSAR2 in C. roseus petals led to up-regulation of the genes involved in the ir...
Source: Plant and Cell Physiology - December 15, 2016 Category: Cytology Authors: Mertens, J., Van Moerkercke, A., Vanden Bossche, R., Pollier, J., Goossens, A. Tags: Regular Papers Source Type: research
Reactive Carbonyl Species Mediate ABA Signaling in Guard Cells
Drought is responsible for a massive reduction in crop yields. In response to drought, plants synthesize the hormone ABA, which induces stomatal closure, thus reducing water loss. In guard cells, ABA triggers production of reactive oxygen species (ROS), which is mediated by NAD(P)H oxidases. The production of ROS is a key factor for ABA-induced stomatal closure, but it remains to be clarified how the production of ROS is transduced into downstream signaling components in guard cells. We investigated roles of reactive carbonyl species (RCS) in ABA-induced stomatal closure using transgenic tobacco (Nicotiana tabacum) overexp...
Source: Plant and Cell Physiology - December 15, 2016 Category: Cytology Authors: Islam, M. M., Ye, W., Matsushima, D., Munemasa, S., Okuma, E., Nakamura, Y., Biswas, S., Mano, J., Murata, Y. Tags: Regular Papers Source Type: research
Transcription Factor WRKY62 Plays a Role in Pathogen Defense and Hypoxia-Responsive Gene Expression in Rice
WRKY62 is a transcriptional repressor regulated downstream of WRKY45, a central transcription factor of the salicylic acid signaling pathway in rice. Previously, WRKY62 was reported to regulate defense negatively. However, our expressional analysis using WRKY62-knockdown rice indicated that WRKY62 positively regulates defense genes, including diterpenoid phytoalexin biosynthetic genes and their transcriptional regulator DPF. Blast and leaf blight resistance tests also showed that WRKY62 is a positive defense regulator. Yeast two-hybrid, co-immunoprecipitation and gel-shift assays showed that WRKY45 and WRKY62 can form a he...
Source: Plant and Cell Physiology - December 15, 2016 Category: Cytology Authors: Fukushima, S., Mori, M., Sugano, S., Takatsuji, H. Tags: Regular Papers Source Type: research
Oil Biosynthesis in Underground Oil-Rich Storage Vegetative Tissue: Comparison of Cyperus esculentus Tuber with Oil Seeds and Fruits
Cyperus esculentus is unique in that it can accumulate rich oil in its tubers. However, the underlying mechanism of tuber oil biosynthesis is still unclear. Our transcriptional analyses of the pathways from pyruvate production up to triacylglycerol (TAG) accumulation in tubers revealed many distinct species-specific lipid expression patterns from oil seeds and fruits, indicating that in C. esculentus tuber: (i) carbon flux from sucrose toward plastid pyruvate could be produced mostly through the cytosolic glycolytic pathway; (ii) acetyl-CoA synthetase might be an important contributor to acetyl-CoA formation for plastid fa...
Source: Plant and Cell Physiology - December 15, 2016 Category: Cytology Authors: Yang, Z., Ji, H., Liu, D. Tags: Regular Papers Source Type: research
High Silicon Accumulation in the Shoot is Required for Down-Regulating the Expression of Si Transporter Genes in Rice
In conclusion, the Si-induced down-regulation of Si transporter genes is controlled by shoot Si, not root Si, and the region between –327 and –292 in the OsLsi1 promoter is involved in this regulation of OsLsi1 expression in rice. (Source: Plant and Cell Physiology)
Source: Plant and Cell Physiology - December 15, 2016 Category: Cytology Authors: Mitani-Ueno, N., Yamaji, N., Ma, J. F. Tags: Regular Papers Source Type: research
Molecular Characterization of Soybean Pterocarpan 2-Dimethylallyltransferase in Glyceollin Biosynthesis: Local Gene and Whole-Genome Duplications of Prenyltransferase Genes Led to the Structural Diversity of Soybean Prenylated Isoflavonoids
In this study, we identified four genes that encode isoflavonoid PTs, including (–)-glycinol 2-dimethylallyltransferase (G2DT), using homology-based in silico screening and biochemical characterization in yeast expression systems. Transcript analyses illustrated that changes in G2DT gene expression were correlated with the induction of glyceollins II, III, IV and V in elicitor-treated soybean cells and leaves, suggesting its involvement in glyceollin biosynthesis. Moreover, the genomic signatures of these PT genes revealed that G4DT and G2DT are paralogs derived from whole-genome duplications of the soybean genome, w...
Source: Plant and Cell Physiology - December 15, 2016 Category: Cytology Authors: Yoneyama, K., Akashi, T., Aoki, T. Tags: Regular Papers Source Type: research
Allantoin Increases Cadmium Tolerance in Arabidopsis via Activation of Antioxidant Mechanisms
Plants apply various molecular, physiological and morphological strategies in response to undesirable environmental conditions. One of the possible responses which may contribute to surviving stressful conditions is the accumulation of ureides. Ureides are recognized as important nitrogen-rich compounds involved in recycling nitrogen in plants to support growth and reproduction. Amongst them, allantoin not only serves as a transportable nitrogen-rich compound, but has also been suggested to protect plants from abiotic stresses via minimizing oxidative damage. This work focuses on the effect of cadmium (Cd) on ureide metabo...
Source: Plant and Cell Physiology - December 15, 2016 Category: Cytology Authors: Nourimand, M., Todd, C. D. Tags: Regular Papers Source Type: research
NbCZF1, a Novel C2H2-Type Zinc Finger Protein, as a New Regulator of SsCut-Induced Plant Immunity in Nicotiana benthamiana
In this study, we utilized Nicotiana benthamiana and virus-induced gene silencing to decrease the expression of > 2,500 genes individually. Using this forward genetics approach, several genes were identified that, when silenced, compromised SsCut-triggered cell death based on a cell death assay. A C2H2-type zinc finger gene was isolated from N. benthamiana. Sequence analysis indicated that the gene encodes a 27 kDa protein with 253 amino acids containing two typical C2H2-type zinc finger domains; this gene was named NbCZF1. We found that SsCut-induced cell death could be inhibited by virus-induced gene silencing of NbCZ...
Source: Plant and Cell Physiology - December 15, 2016 Category: Cytology Authors: Zhang, H., Zhao, T., Zhuang, P., Song, Z., Du, H., Tang, Z., Gao, Z. Tags: Regular Papers Source Type: research
Sulfoquinovosyldiacylglycerol has an Essential Role in Thermosynechococcus elongatus BP-1 Under Phosphate-Deficient Conditions
In this study, we inactivated the sqdB gene, encoding a UDP-sulfoquinovose synthase and involved in SQDG biosynthesis, in Thermosynechococcus elongatus BP-1. In wild-type cells, PG accounted for only approximately 3.5 mol% of total membrane lipids, but its content was substantially increased along with complete loss of SQDG in the sqdB mutant. Under phosphate (Pi)-sufficient conditions, the growth rate and PSII activity were slightly lower in sqdB than in wild-type cells. In addition, the formation of PSI trimers and PSII dimers and energy transfer in phycobilisomes were perturbed in the mutant. Under Pi-deficient conditio...
Source: Plant and Cell Physiology - December 15, 2016 Category: Cytology Authors: Endo, K., Kobayashi, K., Wada, H. Tags: Regular Papers Source Type: research
Increased Photochemical Efficiency in Cyanobacteria via an Engineered Sucrose Sink
In plants, a limited capacity to utilize or export the end-products of the Calvin–Benson cycle (CB) from photosynthetically active source cells to non-photosynthetic sink cells can result in reduced carbon capture and photosynthetic electron transport (PET), and lowered photochemical efficiency. The down-regulation of photosynthesis caused by reduced capacity to utilize photosynthate has been termed ‘sink limitation’. Recently, several cyanobacterial and algal strains engineered to overproduce target metabolites have exhibited increased photochemistry, suggesting that possible source–sink regulatory...
Source: Plant and Cell Physiology - December 15, 2016 Category: Cytology Authors: Abramson, B. W., Kachel, B., Kramer, D. M., Ducat, D. C. Tags: Regular Papers Source Type: research
