Carotenoid Biosynthesis in Calothrix sp. 336/3: Composition of Carotenoids on Full Medium, During Diazotrophic Growth and After Long-Term H2 Photoproduction
The carotenoid composition of the filamentous heterocystous N2-fixing cyanobacterium Calothrix sp. 336/3 was investigated under three conditions: in full medium (non-diazotrophic growth); in the absence of combined nitrogen (diazotrophic growth); and after long-term H2 photoproduction (diazotrophic medium and absence of nitrogen in the atmosphere). Anabaena sp. PCC 7120 and its hupL mutant with disrupted uptake hydrogenase were used as reference strains. Analysis of identified carotenoids and enzymes involved in carotenogenesis showed the presence of three distinct biosynthetic pathways in Calothrix sp. 336/3. The first on...
Source: Plant and Cell Physiology - November 3, 2016 Category: Cytology Authors: Kosourov, S., Murukesan, G., Jokela, J., Allahverdiyeva, Y. Tags: Regular Papers Source Type: research
Combination of Synthetic Chemistry and Live-Cell Imaging Identified a Rapid Cell Division Inhibitor in Tobacco and Arabidopsis thaliana
Cell proliferation is crucial to the growth of multicellular organisms, and thus the proper control of cell division is important to prevent developmental arrest or overgrowth. Nevertheless, tools for controlling cell proliferation are still poor in plant. To develop novel tools, we focused on a specific compound family, triarylmethanes, whose members show various antiproliferative activities in animals. By combining organic chemistry to create novel and diverse compounds containing the triarylmethyl moiety and biological screens based on live-cell imaging of a fluorescently labeled tobacco Bright Yellow-2 (BY-2) culture c...
Source: Plant and Cell Physiology - November 3, 2016 Category: Cytology Authors: Nambo, M., Kurihara, D., Yamada, T., Nishiwaki-Ohkawa, T., Kadofusa, N., Kimata, Y., Kuwata, K., Umeda, M., Ueda, M. Tags: Regular Papers Source Type: research
HSP90 Stabilizes Auxin-Responsive Phenotypes by Masking a Mutation in the Auxin Receptor TIR1
Heat shock protein 90 (HSP90) is a molecular chaperone that is required for the function of various substrate proteins, also known as client proteins. It is proposed that HSP90 buffers or hides phenotypic variations in animals and plants by masking mutations in some of its client proteins. However, none of the client proteins with cryptic mutations has been identified to date. Here, we identify the first client protein example by which HSP90 buffers a mutation: the auxin receptor transport inhibitor response 1 (TIR1). TIR1 interacts with HSP90 in the nucleus. An HSP90-specific inhibitor abolished the nuclear localization o...
Source: Plant and Cell Physiology - November 3, 2016 Category: Cytology Authors: Watanabe, E., Mano, S., Nomoto, M., Tada, Y., Hara-Nishimura, I., Nishimura, M., Yamada, K. Tags: Rapid Paper Source Type: research
CyAbrB2 Contributes to the Transcriptional Regulation of Low CO2 Acclimation in Synechocystis sp. PCC 6803
Acclimation to low CO2 conditions in cyanobacteria involves the co-ordinated regulation of genes mainly encoding components of the carbon-concentrating mechanism (CCM). Making use of several independent microarray data sets, a core set of CO2-regulated genes was defined for the model strain Synechocystis sp. PCC 6803. On the transcriptional level, the CCM is mainly regulated by the well-characterized transcriptional regulators NdhR (= CcmR) and CmpR. However, the role of an additional regulatory protein, namely cyAbrB2 belonging to the widely distributed AbrB regulator family that was originally characterized in the genus ...
Source: Plant and Cell Physiology - October 9, 2016 Category: Cytology Authors: Orf, I., Schwarz, D., Kaplan, A., Kopka, J., Hess, W. R., Hagemann, M., Klähn, S. Tags: Regular Papers Source Type: research
Calcium- and Nitric Oxide-Dependent Nuclear Accumulation of Cytosolic Glyceraldehyde-3-Phosphate Dehydrogenase in Response to Long Chain Bases in Tobacco BY-2 Cells
Sphinganine or dihydrosphingosine (d18:0, DHS), one of the most abundant free sphingoid long chain bases (LCBs) in plants, is known to induce a calcium-dependent programmed cell death (PCD) in plants. In addition, in tobacco BY-2 cells, it has been shown that DHS triggers a rapid production of H2O2 and nitric oxide (NO). Recently, in analogy to what is known in the animal field, plant cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPC), a ubiquitous enzyme involved in glycolysis, has been suggested to fulfill other functions associated with its oxidative post-translational modifications such as S-nitrosylation on cys...
Source: Plant and Cell Physiology - October 9, 2016 Category: Cytology Authors: Testard, A., Da Silva, D., Ormancey, M., Pichereaux, C., Pouzet, C., Jauneau, A., Grat, S., Robe, E., Briere, C., Cotelle, V., Mazars, C., Thuleau, P. Tags: Regular Papers Source Type: research
Analysis of Rhizome Development in Oryza longistaminata, a Wild Rice Species
Vegetative reproduction is a form of asexual propagation in plants. A wide range of plants develop rhizomes, modified stems that grow underground horizontally, as a means of vegetative reproduction. In rhizomatous species, despite their distinct developmental patterns, both rhizomes and aerial shoots derive from axillary buds. Therefore, it is of interest to understand the basis of rhizome initiation and development. Oryza longistaminata, a wild rice species, develops rhizomes. We analyzed bud initiation and growth of O. longistaminata rhizomes using various methods of morphological observation. We show that, unlike aerial...
Source: Plant and Cell Physiology - October 9, 2016 Category: Cytology Authors: Yoshida, A., Terada, Y., Toriba, T., Kose, K., Ashikari, M., Kyozuka, J. Tags: Regular Papers Source Type: research
The Pepper RING-Type E3 Ligase, CaAIP1, Functions as a Positive Regulator of Drought and High Salinity Stress Responses
Plant adaptive responses to osmotic stress are co-ordinated by restriction of growth and developmental processes and by molecular and physiological activities. The phytohormone ABA is the primary regulator that induces and responds to osmotic stress, and its sensitivity markedly influences osmotic stress tolerance levels. Several E3 ubiquitin ligases act as positive or negative regulators of ABA, thereby mediating sensitivity to osmotic stress in higher plants. Here, we report that the C3H2C3-type RING finger E3 ligase, CaAIP1, regulates osmotic stress responses via ABA-mediated signaling. CaAIP1 contains a RING finger mot...
Source: Plant and Cell Physiology - October 9, 2016 Category: Cytology Authors: Park, C., Lim, C. W., Lee, S. C. Tags: Regular Papers Source Type: research
Auxin Influx Carrier AUX1 Confers Acid Resistance for Arabidopsis Root Elongation Through the Regulation of Plasma Membrane H+-ATPase
The plant plasma membrane (PM) H+-ATPase regulates pH homeostasis and cell elongation in roots through the formation of an electrochemical H+ gradient across the PM and a decrease in apoplastic pH; however, the detailed signaling for the regulation of PM H+-ATPases remains unclear. Here, we show that an auxin influx carrier, AUXIN RESISTANT1 (AUX1), is required for the maintenance of PM H+-ATPase activity and proper root elongation. We isolated a low pH-hypersensitive 1 (loph1) mutant by a genetic screen of Arabidopsis thaliana on low pH agar plates. The loph1 mutant is a loss-of-function mutant of the AUX1 gene and exhibi...
Source: Plant and Cell Physiology - October 9, 2016 Category: Cytology Authors: Inoue, S.-i., Takahashi, K., Okumura-Noda, H., Kinoshita, T. Tags: Regular Papers Source Type: research
A Gene Encoding Pentatricopeptide Repeat Protein Partially Restores Fertility in RT98-Type Cytoplasmic Male-Sterile Rice
Cytoplasmic male sterility (CMS) lines in rice, which have the cytoplasm of a wild species and the nuclear genome of cultivated rice, are of value for the study of genetic interactions between the mitochondrial and nuclear genomes. The RT98-type CMS line RT98A and the fertility restorer line RT98C carry the cytoplasm of the wild species Oryza rufipogon and the nuclear genome of the Taichung 65 cultivar (Oryza sativa L.). Based on a classical crossing experiment, fertility is reported to be restored gametophytically by the presence of a tentative single gene, designated Rf98, which is derived from the cytoplasm donor. Fine ...
Source: Plant and Cell Physiology - October 9, 2016 Category: Cytology Authors: Igarashi, K., Kazama, T., Toriyama, K. Tags: Regular Papers Source Type: research
The Blue Light-Dependent Polyubiquitination and Degradation of Arabidopsis Cryptochrome2 Requires Multiple E3 Ubiquitin Ligases
Cryptochromes are blue light receptors regulated by light-dependent ubiquitination and degradation in both plant and animal lineages. The Arabidopsis genome encodes two cryptochromes, CRY1 and CRY2, of which CRY2 undergoes blue light-dependent ubiquitination and 26S proteasome-dependent degradation. The molecular mechanism regulating blue light-dependent proteolysis of CRY2 is still not fully understood. We found that the F-box proteins ZEITLUPE (ZTL) and Lov Kelch Protein2 (LKP2), which mediate blue light suppression of degradation of the CRY2 signaling partner CIB1, are not required for the blue light-dependent CRY2 degr...
Source: Plant and Cell Physiology - October 9, 2016 Category: Cytology Authors: Liu, Q., Wang, Q., Liu, B., Wang, W., Wang, X., Park, J., Yang, Z., Du, X., Bian, M., Lin, C. Tags: Regular Papers Source Type: research
Ultrastructural Immunolocalization of Arabinogalactan Protein, Pectin and Hemicellulose Epitopes Through Anther Development in Brassica napus
In this work, we performed an extensive and detailed analysis of the changes in cell wall composition during Brassica napus anther development. We used immunogold labeling to study the spatial and temporal patterns of the composition and distribution of different arabinogalactan protein (AGP), pectin, xyloglucan and xylan epitopes in high-pressure-frozen/freeze-substituted anthers, quantifying and comparing their relative levels in the different anther tissues and developmental stages. We used the following monoclonal antibodies: JIM13, JIM8, JIM14 and JIM16 for AGPs, LM5, LM6, JIM7, JIM5 and LM7 for pectins, CCRC-M1, CCRC...
Source: Plant and Cell Physiology - October 9, 2016 Category: Cytology Authors: Corral-Martinez, P., Garcia-Fortea, E., Bernard, S., Driouich, A., Segui-Simarro, J. M. Tags: Regular Papers Source Type: research
Synergistic Activation of RD29A Via Integration of Salinity Stress and Abscisic Acid in Arabidopsis thaliana
Plants perceive information from the surroundings and elicit appropriate molecular responses. How plants dynamically respond to combinations of external inputs is yet to be revealed, despite the detailed current knowledge of intracellular signaling pathways. We measured dynamics of Response-to-Dehydration 29A (RD29A) expression induced by single or combined NaCl and ABA treatments in Arabidopsis thaliana. RD29A expression in response to a combination of NaCl and ABA leads to unique dynamic behavior that cannot be explained by the sum of responses to individual NaCl and ABA. To explore the potential mechanisms responsible f...
Source: Plant and Cell Physiology - October 9, 2016 Category: Cytology Authors: Lee, S. Y., Boon, N. J., Webb, A. A. R., Tanaka, R. J. Tags: Regular Papers Source Type: research
Metabolic and Transcriptional Analysis of Durum Wheat Responses to Elevated CO2 at Low and High Nitrate Supply
In conclusion, the photosynthetic acclimation in LN plants was associated with an inhibition of leaf NO3– assimilation, whereas up-regulation of N metabolism in roots could have mitigated the acclimatory effect of eCO2 in HN plants. (Source: Plant and Cell Physiology)
Source: Plant and Cell Physiology - October 9, 2016 Category: Cytology Authors: Vicente, R., Perez, P., Martinez-Carrasco, R., Feil, R., Lunn, J. E., Watanabe, M., Arrivault, S., Stitt, M., Hoefgen, R., Morcuende, R. Tags: Regular Papers Source Type: research
CHLORORESPIRATORY REDUCTION 9 is a Novel Factor Required for Formation of Subcomplex A of the Chloroplast NADH Dehydrogenase-Like Complex
In vascular plants, the chloroplast NADH dehydrogenase-like (NDH) complex, a homolog of respiratory NADH:quinone oxidoreductase (Complex I), mediates plastoquinone reduction using ferredoxin as an electron donor in cyclic electron transport around PSI in the thylakoid membrane. In angiosperms, chloroplast NDH is composed of five subcomplexes and forms a supercomplex with PSI. The modular assembly of stroma-protruded subcomplex A, which corresponds to the Q module of Complex I, was recently reported. However, the factors involved in the specific assembly steps have not been completely identified. Here, we isolated an Arabid...
Source: Plant and Cell Physiology - October 9, 2016 Category: Cytology Authors: Yamamoto, H., Fan, X., Sugimoto, K., Fukao, Y., Peng, L., Shikanai, T. Tags: Regular Papers Source Type: research
Enhanced Ascorbate Regeneration Via Dehydroascorbate Reductase Confers Tolerance to Photo-Oxidative Stress in Chlamydomonas reinhardtii
The role of ascorbate (AsA) recycling via dehydroascorbate reductase (DHAR) in the tolerance of Chlamydomonas reinhardtii to photo-oxidative stress was examined. The activity of DHAR and the abundance of the CrDHAR1 (Cre10.g456750) transcript increased after moderate light (ML; 750 µmol m–2 s–1) or high light (HL; 1,800 µmol m–2 s–1) illumination, accompanied by dehydroascorbate (DHA) accumulation, decreased AsA redox state, photo-inhibition, lipid peroxidation, H2O2 overaccumulation, growth inhibition and cell death. It suggests that DHAR and AsA recycling is limiting under high-intensi...
Source: Plant and Cell Physiology - October 9, 2016 Category: Cytology Authors: Lin, S.-T., Chiou, C.-W., Chu, Y.-L., Hsiao, Y., Tseng, Y.-F., Chen, Y.-C., Chen, H.-J., Chang, H.-Y., Lee, T.-M. Tags: Regular Papers Source Type: research
