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Xing Wang Deng - One of the best experts on this subject based on the ideXlab platform.
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photobiology light signal transduction and Photomorphogenesis
Journal of Integrative Plant Biology, 2020Co-Authors: Xing Wang DengAbstract:Light is crucial for plants, not only because of photosynthesis, but also because of Photomorphogenesis. As one of the most important environmental cues, light influences multiple responses in plants, including seed germination, seedling de-etiolation, shade avoidance, phototropism, stomata and chloroplast movement, circadian rhythms, and flowering time. This article is protected by copyright. All rights reserved.
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arabidopsis pp6 phosphatases dephosphorylate pif proteins to repress Photomorphogenesis
Proceedings of the National Academy of Sciences of the United States of America, 2019Co-Authors: Xiaodan Yu, Jie Dong, William Terzaghi, Haodong Chen, Zhaoguo Deng, Yaping Jiang, Chong Wu, Xing Wang DengAbstract:The PHYTOCHROME-INTERACTING FACTORs (PIFs) play a central role in repressing Photomorphogenesis, and phosphorylation mediates the stability of PIF proteins. Although the kinases responsible for PIF phosphorylation have been extensively studied, the phosphatases that dephosphorylate PIFs remain largely unknown. Here, we report that seedlings with mutations in FyPP1 and FyPP3, 2 genes encoding the catalytic subunits of protein phosphatase 6 (PP6), exhibited short hypocotyls and opened cotyledons in the dark, which resembled the photomorphogenic development of dark-grown pifq mutants. The hypocotyls of dark-grown sextuple mutant fypp1 fypp3 (f1 f3) pifq were shorter than those of parental mutants f1 f3 and pifq, indicating that PP6 phosphatases and PIFs function synergistically to repress Photomorphogenesis in the dark. We showed that FyPPs directly interacted with PIF3 and PIF4, and PIF3 and PIF4 proteins exhibited mobility shifts in f1 f3 mutants, consistent with their hyperphosphorylation. Moreover, PIF4 was more rapidly degraded in f1 f3 mutants than in wild type after light exposure. Whole-genome transcriptomic analyses indicated that PP6 and PIFs coregulated many genes, and PP6 proteins may positively regulate PIF transcriptional activity. These data suggest that PP6 phosphatases may repress Photomorphogenesis by controlling the stability and transcriptional activity of PIF proteins via regulating PIF phosphorylation.
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cop1 suppressor 4 promotes seedling Photomorphogenesis by repressing cca1 and pif4 expression in arabidopsis
Proceedings of the National Academy of Sciences of the United States of America, 2018Co-Authors: Xianhai Zhao, Xing Wang Deng, Yan Jiang, Jian Li, Jeffrey Z Chen, Dongqing XuAbstract:CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) and DE-ETIOLATED 1 (DET1) are founding components of two central repressor complexes of Photomorphogenesis that trigger the degradation of a larger number of photomorphogenic-promoting factors in darkness. Here, we identify COP1 SUPPRESSOR 4 (CSU4) as a genetic suppressor of the cop1-6 mutation. Mutations in CSU4 largely rescued the constitutively photomorphogenic phenotype of cop1-6 and det1-1 in darkness. Loss of CSU4 function resulted in significantly longer hypocotyl in the light. Further biochemical studies revealed that CSU4 physically interacts with CIRCADIAN CLOCK-ASSOCIATED 1 (CCA1) and negatively regulates its transcriptional repression activity toward its targets. CSU4 represses the expression of CCA1 in the early morning and of PHYTOCHROME INTERACTING FACTOR 4 (PIF4) in the early evening. Our study suggests that CSU4 acts as a negative regulator of CCA1 via physically associating with CCA1, which in turn, likely serves to repress expression of CCA1 and PIF4 to promote Photomorphogenesis.
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beyond repression of Photomorphogenesis role switching of cop det fus in light signaling
Current Opinion in Plant Biology, 2014Co-Authors: Xi Huang, Xing Wang Deng, Xinhao OuyangAbstract:Light is a pivotal environmental stimulus that promotes plant Photomorphogenesis. Substantial progress has been achieved in defining the central repressors of Photomorphogenesis, the CONSTITUTIVE PHOTOMORPHOGENIC / DE-ETIOLATED / FUSCA ( COP / DET / FUS ) loci, in the past 20 years. COP/DET/FUS proteins are well-conserved, and regulate a variety of biological processes in plants and animals. The fact that these proteins contribute to the repression of plant Photomorphogenesis by regulating the ubiquitin-proteasome-dependent pathway has been well established. Recently, molecular insight has been gained into the functional diversity of COP/DET/FUS. Here, we review the current research on the roles of COP/DET/FUS, with a focus on the functional conversion of COP1 in Photomorphogenesis.
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arabidopsis de etiolated1 represses Photomorphogenesis by positively regulating phytochrome interacting factors in the dark
The Plant Cell, 2014Co-Authors: Jie Dong, Dafang Tang, Renbo Yu, Kunlun Li, Hang He, William Terzaghi, Xing Wang Deng, Haodong ChenAbstract:Arabidopsis thaliana seedlings undergo photomorphogenic development even in darkness when the function of DE-ETIOLATED1 (DET1), a repressor of Photomorphogenesis, is disrupted. However, the mechanism by which DET1 represses Photomorphogenesis remains unclear. Our results indicate that DET1 directly interacts with a group of transcription factors known as the phytochrome-interacting factors (PIFs). Furthermore, our results suggest that DET1 positively regulates PIF protein levels primarily by stabilizing PIF proteins in the dark. Genetic analysis showed that each pif single mutant could enhance the det1-1 phenotype, and ectopic expression of each PIF in det1-1 partially suppressed the det1-1 phenotype, based on hypocotyl elongation and cotyledon opening angles observed in darkness. Genomic analysis also revealed that DET1 may modulate the expression of light-regulated genes to mediate Photomorphogenesis partially through PIFs. The observed interaction and regulation between DET1 and PIFs not only reveal how DET1 represses Photomorphogenesis, but also suggest a possible mechanism by which two groups of photomorphogenic repressors, CONSTITUTIVE Photomorphogenesis/DET/FUSCA and PIFs, work in concert to repress Photomorphogenesis in darkness.
Shuhsing Wu - One of the best experts on this subject based on the ideXlab platform.
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hua enhancer1 is involved in posttranscriptional regulation of positive and negative regulators in arabidopsis Photomorphogenesis
The Plant Cell, 2014Co-Authors: Huanglung Tsai, Yi Hang Li, Wenping Hsieh, Shuhsing WuAbstract:Light regulates growth and developmental processes in plants via global transcriptome adjustment, translational control, and multilayered posttranslational modification of proteins. The transcriptional activation and repression of light-responsive genes has been well documented; however, the impact of posttranscriptional regulation on conveying light signals has been less addressed. Here, we examined whether optimal Photomorphogenesis in Arabidopsis thaliana requires the proper biogenesis of small regulatory RNAs that play pivotal roles in the posttranscriptional regulation of gene expression. Arabidopsis carrying a mutation in HUA ENHANCER1 (HEN1), required for stabilization of small regulatory RNAs, showed defects in multiple aspects of photomorphogenic and skotomorphogenic development. HEN1 negatively regulated Arabidopsis Photomorphogenesis. Light-activated HEN1 expression depended on the photoreceptors phytochrome A (phyA), phyB, cryptochrome 1 (cry1), and cry2 and key transcriptional regulators ELONGATED HYPOCOTYL5 (HY5) and HY5-HOMOLOG. We also demonstrate the involvement of the small regulatory RNAs miR157d and miR319 in modulating the expression of a positive regulator, HY5, and negative regulators TEOSINTE BRANCHED1, CYCLOIDEA AND PCF family proteins, respectively, for optimal photomorphogenic development in Arabidopsis.
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widespread translational control contributes to the regulation of arabidopsis Photomorphogenesis
Molecular Systems Biology, 2012Co-Authors: Szuhsien Wu, Homing Chen, Shuhsing WuAbstract:Environmental ‘light' has a vital role in regulating plant growth and development. Transcriptomic profiling has been widely used to examine how light regulates mRNA levels on a genome-wide scale, but the global role of translational regulation in the response to light is unknown. Through a transcriptomic comparison of steady-state and polysome-bound mRNAs, we reveal a clear impact of translational control on thousands of genes, in addition to transcriptomic changes, during Photomorphogenesis. Genes encoding ribosomal protein are preferentially regulated at the translational level, which possibly contributes to the enhanced translation efficiency. We also reveal that mRNAs regulated at the translational level share characteristics of longer half-lives and shorter cDNA length, and that transcripts with a cis-element, TAGGGTTT, in their 5′ untranslated region have higher translatability. We report a previously neglected aspect of gene expression regulation during Arabidopsis Photomorphogenesis. The identities and molecular signatures associated with mRNAs regulated at the translational level also offer new directions for mechanistic studies of light-triggered translational enhancement in Arabidopsis.
Xi Huang - One of the best experts on this subject based on the ideXlab platform.
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beyond repression of Photomorphogenesis role switching of cop det fus in light signaling
Current Opinion in Plant Biology, 2014Co-Authors: Xi Huang, Xing Wang Deng, Xinhao OuyangAbstract:Light is a pivotal environmental stimulus that promotes plant Photomorphogenesis. Substantial progress has been achieved in defining the central repressors of Photomorphogenesis, the CONSTITUTIVE PHOTOMORPHOGENIC / DE-ETIOLATED / FUSCA ( COP / DET / FUS ) loci, in the past 20 years. COP/DET/FUS proteins are well-conserved, and regulate a variety of biological processes in plants and animals. The fact that these proteins contribute to the repression of plant Photomorphogenesis by regulating the ubiquitin-proteasome-dependent pathway has been well established. Recently, molecular insight has been gained into the functional diversity of COP/DET/FUS. Here, we review the current research on the roles of COP/DET/FUS, with a focus on the functional conversion of COP1 in Photomorphogenesis.
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Beyond repression of Photomorphogenesis: role switching of COP/DET/FUS in light signaling.
Current Opinion in Plant Biology, 2014Co-Authors: Xi Huang, Xinhao Ouyang, Xing Wang DengAbstract:Light is a pivotal environmental stimulus that promotes plant Photomorphogenesis. Substantial progress has been achieved in defining the central repressors of Photomorphogenesis, the CONSTITUTIVE PHOTOMORPHOGENIC / DE-ETIOLATED / FUSCA ( COP / DET / FUS ) loci, in the past 20 years. COP/DET/FUS proteins are well-conserved, and regulate a variety of biological processes in plants and animals. The fact that these proteins contribute to the repression of plant Photomorphogenesis by regulating the ubiquitin-proteasome-dependent pathway has been well established. Recently, molecular insight has been gained into the functional diversity of COP/DET/FUS. Here, we review the current research on the roles of COP/DET/FUS, with a focus on the functional conversion of COP1 in Photomorphogenesis.
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phytochrome interacting factor1 enhances the e3 ligase activity of constitutive photomorphogenic1 to synergistically repress Photomorphogenesis in arabidopsis
The Plant Cell, 2014Co-Authors: Xiaosa Xu, Xing Wang Deng, Xi Huang, Inyup Paik, Qingyun BuAbstract:CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) is a RING/WD40 repeat–containing ubiquitin E3 ligase that is conserved from plants to humans. COP1 forms complexes with SUPPRESSOR OF PHYTOCHROME A (SPA) proteins, and these complexes degrade positively acting transcription factors in the dark to repress Photomorphogenesis. Phytochrome-interacting basic helix-loop-helix transcription factors (PIFs) also repress Photomorphogenesis in the dark. In response to light, the phytochrome family of sensory photoreceptors simultaneously inactivates COP1-SPA complexes and induces the rapid degradation of PIFs to promote Photomorphogenesis. However, the functional relationship between PIFs and COP1-SPA complexes is still unknown. Here, we present genetic evidence that the pif and cop1/spa Arabidopsis thaliana mutants synergistically promote Photomorphogenesis in the dark. LONG HYPOCOTYL5 (HY5) is stabilized in the cop1 pif1, spa123 pif1, and pif double, triple, and quadruple mutants in the dark. Moreover, the hy5 mutant suppresses the constitutive photomorphogenic phenotypes of the pifq mutant in the dark. PIF1 forms complexes with COP1, HY5, and SPA1 and enhances the substrate recruitment and autoubiquitylation and transubiquitylation activities of COP1. These data uncover a novel function of PIFs as the potential cofactors of COP1 and provide a genetic and biochemical model of how PIFs and COP1-SPA complexes synergistically repress Photomorphogenesis in the dark.
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arabidopsis cullin4 damaged dna binding protein 1 interacts with constitutively photomorphogenic1 suppressor of phya complexes to regulate Photomorphogenesis and flowering time
The Plant Cell, 2010Co-Authors: William Terzaghi, Haodong Chen, Xi Huang, Giuliana Gusmaroli, Yuki Yanagawa, Yu Zhang, Jigang LiAbstract:CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1) possesses E3 ligase activity and promotes degradation of key factors involved in the light regulation of plant development. The finding that CULLIN4 (CUL4)-Damaged DNA Binding Protein1 (DDB1) interacts with DDB1 binding WD40 (DWD) proteins to act as E3 ligases implied that CUL4-DDB1 may associate with COP1-SUPPRESSOR OF PHYA (SPA) protein complexes, since COP1 and SPAs are DWD proteins. Here, we demonstrate that CUL4-DDB1 physically associates with COP1-SPA complexes in vitro and in vivo, likely via direct interaction of DDB1 with COP1 and SPAs. The interactions between DDB1 and COP1, SPA1, and SPA3 were disrupted by mutations in the WDXR motifs of MBP-COP1, His-SPA1, and His-SPA3. CUL4 cosuppression mutants enhanced weak cop1 Photomorphogenesis and flowered early under short days. Early flowering of short day–grown cul4 mutants correlated with increased FLOWERING LOCUS T transcript levels, whereas CONSTANS transcript levels were not altered. De-etiolated1 and COP1 can bind DDB1 and may work with CUL4-DDB1 in distinct complexes, but they mediate Photomorphogenesis in concert. Thus, a series of CUL4-DDB1-COP1-SPA E3 ligase complexes may mediate the repression of Photomorphogenesis and, possibly, of flowering time.
Sourav Datta - One of the best experts on this subject based on the ideXlab platform.
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the b box containing microprotein mip1a bbx31 regulates Photomorphogenesis and uv b protection
Plant Physiology, 2019Co-Authors: Arpita Yadav, Premachandran Yadukrishnan, Souvika Bakshi, Maneesh Lingwan, Ulla Dolde, Stephan Wenkel, Shyam K Masakapalli, Sourav DattaAbstract:The bZIP transcription factor ELONGATED HYPOCOTYL5 (HY5) represents a major hub in the light-signaling cascade both under visible and UV-B light. The mode of transcriptional regulation of HY5, especially under UV-B light, is not well characterized. B-BOX (BBX) transcription factors regulate HY5 transcription and also posttranscriptionally modulate HY5 to control Photomorphogenesis under white light. Here, we identify BBX31 as a key signaling intermediate in visible and UV-B light signal transduction in Arabidopsis (Arabidopsis thaliana). BBX31 expression is induced by UV-B radiation in a fluence-dependent manner. HY5 directly binds to the promoter of BBX31 and regulates its transcript levels. Loss- and gain-of-function mutants of BBX31 indicate that it acts as a negative regulator of Photomorphogenesis under white light but is a positive regulator of UV-B signaling. Genetic interaction studies suggest that BBX31 regulates Photomorphogenesis independent of HY5. We found no evidence for a direct BBX31-HY5 interaction, and they primarily regulate different sets of genes in white light. Under high doses of UV-B radiation, BBX31 promotes the accumulation of UV-protective flavonoids and phenolic compounds. It enhances tolerance to UV-B radiation by regulating genes involved in photoprotection and DNA repair in a HY5-dependent manner. Under UV-B radiation, overexpression of BBX31 enhances HY5 transcriptional levels in a UV RESISTANCE LOCUS8-dependent manner, suggesting that BBX31 might regulate HY5 transcription.
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The B-Box-Containing MicroProtein miP1a/BBX31 Regulates Photomorphogenesis and UV-B Protection.
Plant Physiology, 2019Co-Authors: Arpita Yadav, Premachandran Yadukrishnan, Souvika Bakshi, Maneesh Lingwan, Ulla Dolde, Stephan Wenkel, Shyam K Masakapalli, Sourav DattaAbstract:The bZIP transcription factor ELONGATED HYPOCOTYL5 (HY5) represents a major hub in the light-signaling cascade both under visible and UV-B light. The mode of transcriptional regulation of HY5, especially under UV-B light, is not well characterized. B-BOX (BBX) transcription factors regulate HY5 transcription and also posttranscriptionally modulate HY5 to control Photomorphogenesis under white light. Here, we identify BBX31 as a key signaling intermediate in visible and UV-B light signal transduction in Arabidopsis (Arabidopsis thaliana). BBX31 expression is induced by UV-B radiation in a fluence-dependent manner. HY5 directly binds to the promoter of BBX31 and regulates its transcript levels. Loss- and gain-of-function mutants of BBX31 indicate that it acts as a negative regulator of Photomorphogenesis under white light but is a positive regulator of UV-B signaling. Genetic interaction studies suggest that BBX31 regulates Photomorphogenesis independent of HY5. We found no evidence for a direct BBX31-HY5 interaction, and they primarily regulate different sets of genes in white light. Under high doses of UV-B radiation, BBX31 promotes the accumulation of UV-protective flavonoids and phenolic compounds. It enhances tolerance to UV-B radiation by regulating genes involved in photoprotection and DNA repair in a HY5-dependent manner. Under UV-B radiation, overexpression of BBX31 enhances HY5 transcriptional levels in a UV RESISTANCE LOCUS8-dependent manner, suggesting that BBX31 might regulate HY5 transcription.
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two b box proteins regulate Photomorphogenesis by oppositely modulating hy5 through their diverse c terminal domains
Plant Physiology, 2018Co-Authors: Premachandran Yadukrishnan, Katharina Bursch, Sourav Datta, Henrik JohanssonAbstract:The Arabidopsis (Arabidopsis thaliana) BBX family comprises several positive and negative regulators of Photomorphogenesis. BBX24, a member of BBX structural group IV, acts as a negative regulator of Photomorphogenesis, whereas another member from the same group, BBX21, is a positive regulator. The molecular basis for the functional diversity shown by these related BBX family members is unknown. Using domain-swap lines, we show that the C-terminal regions of BBX24 and BBX21 specify their function. Because both BBX21 and BBX24 work in close association with HY5, we hypothesized that these proteins differentially regulate the levels or activity of HY5 to fulfill their opposite roles. We show that BBX21 can regulate HY5 post-transcriptionally and the two proteins can coordinate to promote Photomorphogenesis. By contrast, BBX24 interferes with the binding of HY5 to the promoter of an anthocyanin biosynthetic gene, possibly by heterodimerizing with HY5 and preventing it from binding DNA. Our finding that both BBX21 and BBX24 regulate HY5 activity post-transcriptionally, in opposite ways, suggests that closely related B-box proteins execute contrasting functions through differential regulation of HY5.
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the arabidopsis b box protein bbx25 interacts with hy5 negatively regulating bbx22 expression to suppress seedling Photomorphogenesis
The Plant Cell, 2013Co-Authors: Sreeramaiah N Gangappa, Magnus Holm, Sourav Datta, Henrik Johansson, Carlos Daniel Crocco, Chamari Hettiarachchi, Javier Francisco BottoAbstract:ELONGATED HYPOCOTYL5 (HY5) is a basic domain/leucine zipper (bZIP) transcription factor, central for the regulation of seedling Photomorphogenesis. Here, we identified a B-BOX (BBX)–containing protein, BBX25/SALT TOLERANCE HOMOLOG, as an interacting partner of HY5, which has been previously found to physically interact with CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1). BBX25 physically interacts with HY5 both in vitro and in vivo. By physiological and genetic approaches, we showed that BBX25 is a negative regulator of seedling Photomorphogenesis. BBX25 and its homolog BBX24 regulate deetiolation processes and hypocotyl shade avoidance response in an additive manner. Moreover, genetic relationships of bbx25 and bbx24 with hy5 and cop1 revealed that BBX25 and BBX24 additively enhance COP1 and suppress HY5 functions. BBX25 accumulates in a light-dependent manner and undergoes COP1-mediated degradation in dark and light conditions. Furthermore, a protoplast cotransfection assay showed that BBX24 and BBX25 repress BBX22 expression by interfering with HY5 transcriptional activity. As HY5 binds to the BBX22 promoter and promotes its expression, our results identify a direct mechanism through which the expression of BBX22 is regulated. We suggest that BBX25 and BBX24 function as transcriptional corepressors, probably by forming inactive heterodimers with HY5, downregulating BBX22 expression for the fine-tuning of light-mediated seedling development.
Edward J. Oakeley - One of the best experts on this subject based on the ideXlab platform.
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Interaction of COP1 and UVR8 regulates UV-B-induced Photomorphogenesis and stress acclimation in Arabidopsis
EMBO Journal, 2009Co-Authors: Jean Jacques Favory, Agnieszka Stec, Luca Rizzini, C. Cloix, Gareth I. Jenkins, Andreas Albert, H. Gruber, Markus Funk, Attila Oravecz, Edward J. OakeleyAbstract:The ultraviolet-B (UV-B) portion of the solar radiation functions as an environmental signal for which plants have evolved specific and sensitive UV-B perception systems. The UV-B-specific UV RESPONSE LOCUS 8 (UVR8) and the multifunctional E3 ubiquitin ligase CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) are key regulators of the UV-B response. We show here that uvr8-null mutants are deficient in UV-B-induced Photomorphogenesis and hypersensitive to UV-B stress, whereas overexpression of UVR8 results in enhanced UV-B Photomorphogenesis, acclimation and tolerance to UV-B stress. By using sun simulators, we provide evidence at the physiological level that UV-B acclimation mediated by the UV-B-specific photoregulatory pathway is indeed required for survival in sunlight. At the molecular level, we demonstrate that the wild type but not the mutant UVR8 and COP1 proteins directly interact in a UV-B-dependent, rapid manner in planta. These data collectively suggest that UV-B-specific interaction of COP1 and UVR8 in the nucleus is a very early step in signalling and responsible for the plant's coordinated response to UV-B ensuring UV-B acclimation and protection in the natural environment.