Non-damaging ultraviolet B(UV-B)light promotes photomorphogenic development and stress acclimation through UV-B-specific signal transduction in Arabidopsis.UV-B irradiation induces monomerization and nuclear transloca...Non-damaging ultraviolet B(UV-B)light promotes photomorphogenic development and stress acclimation through UV-B-specific signal transduction in Arabidopsis.UV-B irradiation induces monomerization and nuclear translocation of the UV-B photoreceptor UV RESISTANCE LOCUS 8(UVR8).However,it is not clear how the nuclear localization of UVR8 leads to changes in global gene expression.Here,we reveal that nuclear UVR8 governs UV-B-responsive transcriptional networks in concert with several previously known transcription factors,including ELONGATED HYPOCOTYL 5(HY5)and PHYTOCHROME INTERACTING FACTOR 4(PIF4).Based on the transcriptomic analysis,we identify MYB13 as a novel positive regulator in UV-B-induced cotyledon expansion and stress acclimation.MYB13 is UV-B inducible and is predominantly expressed in the cotyledons.Our results demonstrate that MYB13 protein functions as a transcription factor to regulate the expression of genes involved in auxin response and flavonoid biosynthesis through direct binding with their promoters.In addition,photoactivated UVR8 interacts with MYB13 in a UV-B-dependent manner and differentially modulates the affinity of MYB13 with its targets.Taken together,our results elucidate the cooperative function of the UV-B photoreceptor UVR8 with various transcription factors in the nucleus to orchestrate the expression of specific sets of downstream genes and,ultimately,mediate plant responses to UV-B light.展开更多
Light serves as the source of energy as well as an information signal for photosynthetic plants. During evolution, plants have acquired the ability to monitor environmental light radiation and adjust their development...Light serves as the source of energy as well as an information signal for photosynthetic plants. During evolution, plants have acquired the ability to monitor environmental light radiation and adjust their developmental patterns to optimally utilize light energy for photosynthesis. The mechanisms of light perception and signal transduction have been comprehensively studied in past decades, mostly in a few model plants, including Arabidopsis thaliana. However, systematic analyses of the origin and evolution of core components involved in light perception and signaling are still lacking. In this study, we took advantage of the recently sequenced genomes and transcriptomes covering all the main Archaeplastida clades in the public domain to identify orthologous genes of core components involved in light perception and signaling and to reconstruct their evolutionary history. Our analyses suggested that acclimation to different distribution of light quality in new environments led to the origination of specific light signaling pathways in plants. The UVR8 (UV Resistance Locus 8) signaling pathway originated during the movement of plants from the deeper sea to shallow water and enabled plants to deal with ultraviolet B light (UV-B). After acquisition of UV-B adaptation, origination of the phytochrome signaling pathway helped plants to colonize water surface where red light became the prominent light energy source. The seedling emergence pathway, which is mediated by a combination of light and phytohormone signals that orchestrate plant growth pattern transitions, originated before the emergence of seed plants. Although cryptochromes and some key components of E3 ubiquitin ligase systems already existed before the divergence of the plant and animal kingdoms, the coevolution and optimization of light perception and downstream signal transduction components, including key transcription factors and E3 ubiquitin ligase systems, are evident during plant terrestrialization.展开更多
Plants reorient their growth towards light to optimize photosynthetic light capture--a process known as phototropism. Phototropins are the photoreceptors essential for phototropic growth towards blue and ultraviolet-A...Plants reorient their growth towards light to optimize photosynthetic light capture--a process known as phototropism. Phototropins are the photoreceptors essential for phototropic growth towards blue and ultraviolet-A （UV- A） light. Here we detail a phototropic response towards UV-B in etiolated Arabidopsis seedlings. We report that early differential growth is mediated by phototropins but clear phototropic bending to UV-B is maintained in photl phot2 double mutants. We further show that this phototropin-independent phototropic response to UV-B requires the UVoB photoreceptor UVR8. Broad UV-B-mediated repression of auxin-responsive genes suggests that UVR8 regulates directional bending by affecting auxin signaling. Kinetic analysis shows that UVR8-dependent directional bending occurs later than the phototropin response. We conclude that plants may use the full short-wavelength spectrum of sunlight to efficiently reorient photosynthetic tissue with incoming light.展开更多
The phytohormone jasmonate(JA)coordinates stress and growth responses to increase plant survival in unfavorable environments.Although JA can enhance plant UV-B stress tolerance,the mechanisms underlying the interactio...The phytohormone jasmonate(JA)coordinates stress and growth responses to increase plant survival in unfavorable environments.Although JA can enhance plant UV-B stress tolerance,the mechanisms underlying the interaction of UV-B and JA in this response remain unknown.In this study,we demonstrate that the UV RESISTANCE LOCUS 8-TEOSINTE BRANCHED1,Cycloidea and PCF 4-LIPOXYGENASE2(UVR8-TCP4-LOX2)module regulates UV-B tolerance dependent on JA signaling pathway in Arabidopsis thaliana.We show that the nucleus-localized UVR8 physically interacts with TCP4 to increase the DNA-binding activity of TCP4 and upregulate the JA biosynthesis gene LOX2.Furthermore,UVR8 activates the expression of LOX2 in a TCP4-dependent manner.Our genetic analysis also provides evidence that TCP4 acts downstream of UVR8 and upstream of LOX2 to mediate plant responses to UV-B stress.Our results illustrate that the UV-B-dependent interaction of UVR8 and TCP4 serves as an important UVR8-TCP4-LOX2 module,which integrates UV-B radiation and JA signaling and represents a new UVR8 signaling mechanism in plants.展开更多
As one of the most important environmental signals for plants,light plays a profound role in regulating virtually every aspect of plant growth and development.Light signals are perceived by plants via several families...As one of the most important environmental signals for plants,light plays a profound role in regulating virtually every aspect of plant growth and development.Light signals are perceived by plants via several families of photoreceptors,among which phytochromes are responsible for absorbing the red(R)and far-red(FR)wavelengths(600–750 nm),cryptochromes(CRYs)perceive the blue(B)/ultraviolet-A(UV-A)wavelengths(320–500 nm),and UV RESISTANCE LOCUS 8(UVR8)is a recently-characterized UV-B(280–320 nm)photoreceptor.展开更多
Plant UV-B responses are mediated by the photoreceptor UV RESISTANCE LOCUS 8 (UVR8). In re-sponse to UV-B irradiation, UVR8 homodimers dissociate into monomers that bind to the E3 ubiquitin ligase CONSTITUTIVE PHOTOMO...Plant UV-B responses are mediated by the photoreceptor UV RESISTANCE LOCUS 8 (UVR8). In re-sponse to UV-B irradiation, UVR8 homodimers dissociate into monomers that bind to the E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1). The in-teraction of the C27 domain in the C-terminal tail of UVR8 with the WD40 domain of COP1 is critical for UV-B sig-naling. However, the function of the last 17 amino acids (C17) of the C-terminus of UVR8, which are adjacent to C27, is unknown, although they are largely conserved in land plants. In this study, we established that Arabidopsis thaliana UVR8 C17 binds to full-length UVR8, but not to COP1, and reduces COP1 binding to the remaining portion of UVR8, including C27. We hypothesized that overexpression of C17 in a wild-type background would have a dominant negative effect on UVR8 activity;however, C17 overexpression caused strong silencing of endogenous UVR8, precluding a detailed analysis. We therefore generated YFP-UVR8N423 transgenic lines, in which C17 was deleted, to examine C17 function in-directly. YFP-UVR8N423 was more active than YFP-UVR8, suggesting that C17 inhibits UV-B signaling by attenuating binding between C27 and COP1. Our study reveals an inhibitory role for UVR8 C17 in fine-tuning UVR8–COP1 interactions during UV-B signaling.展开更多
The plant UV-B photoreceptor UV RESISTANCE LOCUS 8(UVR8)exists as a homodimer in its inactive ground state.Upon UV-B exposure,UVR8monomerizes and interacts with a downstreamkey regulator,theCONSTITUTIVE PHOTOMORPHOGEN...The plant UV-B photoreceptor UV RESISTANCE LOCUS 8(UVR8)exists as a homodimer in its inactive ground state.Upon UV-B exposure,UVR8monomerizes and interacts with a downstreamkey regulator,theCONSTITUTIVE PHOTOMORPHOGENIC 1/SUPPRESSOR OF PHYA(COP1/SPA)E3 ubiquitin ligase complex,to initiate UV-B signaling.Two WD40 proteins,REPRESSOR OF UV-B PHOTOMORPHOGENESIS 1(RUP1)and RUP2 directly interact with monomeric UVR8 and facilitate UVR8 ground state reversion,completing the UVR8 photocycle.Here,we reconstituted the RUP-mediated UVR8 redimerization process in vitro and reported the structure of the RUP2-UVR8^(W285A) complex(2.0A).RUP2 and UVR8^(W285A) formed a heterodimer via two distinct interfaces,designated Interface 1 and 2.The previously characterized Interface 1 is found between the RUP2 WD40 domain and the UVR8 C27 subregion.The newly identified Interface 2 is formed through interactions between the RUP2 WD40 domain and the UVR8 core domain.Disruption of Interface 2 impairedUV-B induced photomorphogenic development in Arabidopsis thaliana.Further biochemical analysis indicated that both interfaces are important for RUP2-UVR8 interactions and RUP2-mediated facilitation of UVR8 redimerization.Our findings suggest that the two-interface-interaction mode is adopted by both RUP2 and COP1 when they interact with UVR8,marking a step forward in understanding the molecular basis that underpins the interactions between UVR8 and its photocycle regulators.展开更多
Ultraviolet-B(UV-B)light is an intrinsic part of sunlight that reaches the earth’s surface,and affects plant survival and adaptation.How plants respond to UV-B light is regulated by the wavelength,intensity and durat...Ultraviolet-B(UV-B)light is an intrinsic part of sunlight that reaches the earth’s surface,and affects plant survival and adaptation.How plants respond to UV-B light is regulated by the wavelength,intensity and duration of UV-B radiation,and is also regulated by photosynthetically active radiation perceived by phytochrome and cryptochrome photore-ceptors.Non-damaging UV-B light promotes plant photomorphogenesis and UV-B acclimation which enhances plant tolerance against UV-B stress.However,high-level UV-B radiation induces DNA damage,generates reactive oxygen species(ROS)and impairs photosynthesis.Plants have evolved efficient mechanisms to utilize informational UV-B signal,and protect themselves from UV-B stress.UV RESISTANCE LOCUS8(UVR8)is a conserved plant-specific UV-B photoreceptor.It interacts with CONSTITUTIVELY PHOTOMORPHOGENIC1(COP1)to initiate UV-B-specific light signal-ing and regulate UV-B responsive gene expression.A set of transcription factors such as ELONGATED HYPOCOTYL5(HY5)function downstream of the UVR8-COP1 module to promote seedling de-etiolation for photomorphogenic development and biosynthesis of sunscreen flavonoids for UV-B stress tolerance.In addition to UVR8 signaling path-ways,plants subjected to damaging UV-B radiation initiate stress protection and repair mechanisms through UVR8-independent pathways.In this review,we summarize the emerging mechanisms underlying UV-B stress acclimation and protection in plants,primarily revealed in the model plant Arabidopsis thaliana.展开更多
Plants have evolved and perfected a series of light receptors to feel the light at different bands and regulate the expression, modification and interaction of related genes in plants through signal transduction. So f...Plants have evolved and perfected a series of light receptors to feel the light at different bands and regulate the expression, modification and interaction of related genes in plants through signal transduction. So far, many photoreceptors have been identified in plants, UVR8 has recently been identified as a receptor for UV-B light. This paper cloned a WD40 gene related to UVR8 protein subunit, named RrRUP2, based on the Rosa rugose transcriptome data, using Rosa rugose “Zi zhi” as experimental materials. The full length of cDNA of the gene was obtained by RT-PCR and RACE methods. The total length of this gene is 1173 bp, and it encodes 390 amino acids. After bioinformatics analysis, the molecular formula C3415H5659N1173O1434S313 was predicted;the relative molecular weight was 96129.27 Da;the theoretical isoelectric point PI value was 5.00;and its instability index was 47.06. The total average hydrophobic index was 0.750. In the secondary structure of RrRUP2 protein, there are 10 α-helix, 45 β-helix, 181 Random coil, and 154 Extended strand. Gene Bank Blast results showed that the amino acid sequence encoded by RrRUP2 was more than 90% homologous with the RUP2 protein of Rosa chinensis, Fragaria, Malus, Pyrus, Prunus, Juglans, Arabidopsis and Tobacco, so it can be inferred that the RrRUP2 gene is a WD repeat-containing protein. Regarding to fluorescence quantitative expression analysis of RrRUP2, we find its experssion pattern is corresponded with the accumulation of anthocyanins.展开更多
Decades of genetic,molecular and biochemical studies in plants have provided foundational knowledge about light sensory proteins and led to their application in synthetic biology.Optogenetic tools take advantage of th...Decades of genetic,molecular and biochemical studies in plants have provided foundational knowledge about light sensory proteins and led to their application in synthetic biology.Optogenetic tools take advantage of the light switchable activity of plant photoreceptors to control intracellular signaling pathways.The recent discovery of the UV-B photoreceptor UV RESISTANCE LOCUS 8 in the model plant Arabidopsis thaliana opens up new avenues for light-controllable methodologies.In this review,we discuss current developments in optogenetic control by UV-B light and its signaling components,as well as rational considerations in the design and applications of UV-B-based optogenetic tools.展开更多
【目的】获得雨生红球藻中紫外抗性蛋白(Uvresistance locus 8,UVR8)的cDNA序列全长,并进行生物信息分析。【方法】以雨生红球藻为研究对象,通过同源克隆方法获得紫外抗性蛋白UVR8的cDNA序列全长,并通过生物信息手段对其理化性质、蛋白...【目的】获得雨生红球藻中紫外抗性蛋白(Uvresistance locus 8,UVR8)的cDNA序列全长,并进行生物信息分析。【方法】以雨生红球藻为研究对象,通过同源克隆方法获得紫外抗性蛋白UVR8的cDNA序列全长,并通过生物信息手段对其理化性质、蛋白结构及系统进化进行分析。【结果】序列分析表明,HaeUVR8的编码区全长为1554 bp,共编码517个氨基酸,预测理论等电点为5.56,理论分子量为54.31 kD。通过BLASTp分析,与拟南芥中UVR8的相似性达到51%,与莱菌衣藻中UVR8的相似性达到59%。通过蛋白保守结构域分析,HaeUVR8蛋白中存在UVR8蛋白的典型结构域,包括7个叶片螺旋结构和保守的色氨酸残基。系统进化分析表明,高等植物和真核绿藻来源UVR8s有共同祖先。【结论】本研究首次获得雨生红球藻中编码UVR8的基因序列,发现其结构与高等植物UVR8相似,暗示二者可能有相似的作用机制,为雨生红球藻中UVR8的表达、功能研究奠定基础,同时为解析雨生红球藻适应紫外光的分子机制提供线索。展开更多
基金grants from the National Key R&D Program of China(2017YFA0506100 and 2016YFA0502900)the National Natural Science Foundation of China(31771347 and 31671378)+1 种基金the National Natural Science Foundation of Fujian(2018J06009)the Fundamental Transcriptional Regulation by UVR8 and TFs Research Funds for the Central Universities(20720190085 and 20720170068).
文摘Non-damaging ultraviolet B(UV-B)light promotes photomorphogenic development and stress acclimation through UV-B-specific signal transduction in Arabidopsis.UV-B irradiation induces monomerization and nuclear translocation of the UV-B photoreceptor UV RESISTANCE LOCUS 8(UVR8).However,it is not clear how the nuclear localization of UVR8 leads to changes in global gene expression.Here,we reveal that nuclear UVR8 governs UV-B-responsive transcriptional networks in concert with several previously known transcription factors,including ELONGATED HYPOCOTYL 5(HY5)and PHYTOCHROME INTERACTING FACTOR 4(PIF4).Based on the transcriptomic analysis,we identify MYB13 as a novel positive regulator in UV-B-induced cotyledon expansion and stress acclimation.MYB13 is UV-B inducible and is predominantly expressed in the cotyledons.Our results demonstrate that MYB13 protein functions as a transcription factor to regulate the expression of genes involved in auxin response and flavonoid biosynthesis through direct binding with their promoters.In addition,photoactivated UVR8 interacts with MYB13 in a UV-B-dependent manner and differentially modulates the affinity of MYB13 with its targets.Taken together,our results elucidate the cooperative function of the UV-B photoreceptor UVR8 with various transcription factors in the nucleus to orchestrate the expression of specific sets of downstream genes and,ultimately,mediate plant responses to UV-B light.
基金National Key R&D Program of China (2017YFA0503800)National Natural Science Foundation of China (31330048, 31621001 and 31570219)+3 种基金Peking-Tsinghua Center for Life Sciences, US NIH grant (GM-47850)the Jiangsu Province Key Project for Scientific Research (16KJA180002)the Young 日ite Scientists Sponsorship Program and Qing Lan project of Jiangsu Provincethe Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).
文摘Light serves as the source of energy as well as an information signal for photosynthetic plants. During evolution, plants have acquired the ability to monitor environmental light radiation and adjust their developmental patterns to optimally utilize light energy for photosynthesis. The mechanisms of light perception and signal transduction have been comprehensively studied in past decades, mostly in a few model plants, including Arabidopsis thaliana. However, systematic analyses of the origin and evolution of core components involved in light perception and signaling are still lacking. In this study, we took advantage of the recently sequenced genomes and transcriptomes covering all the main Archaeplastida clades in the public domain to identify orthologous genes of core components involved in light perception and signaling and to reconstruct their evolutionary history. Our analyses suggested that acclimation to different distribution of light quality in new environments led to the origination of specific light signaling pathways in plants. The UVR8 (UV Resistance Locus 8) signaling pathway originated during the movement of plants from the deeper sea to shallow water and enabled plants to deal with ultraviolet B light (UV-B). After acquisition of UV-B adaptation, origination of the phytochrome signaling pathway helped plants to colonize water surface where red light became the prominent light energy source. The seedling emergence pathway, which is mediated by a combination of light and phytohormone signals that orchestrate plant growth pattern transitions, originated before the emergence of seed plants. Although cryptochromes and some key components of E3 ubiquitin ligase systems already existed before the divergence of the plant and animal kingdoms, the coevolution and optimization of light perception and downstream signal transduction components, including key transcription factors and E3 ubiquitin ligase systems, are evident during plant terrestrialization.
文摘Plants reorient their growth towards light to optimize photosynthetic light capture--a process known as phototropism. Phototropins are the photoreceptors essential for phototropic growth towards blue and ultraviolet-A （UV- A） light. Here we detail a phototropic response towards UV-B in etiolated Arabidopsis seedlings. We report that early differential growth is mediated by phototropins but clear phototropic bending to UV-B is maintained in photl phot2 double mutants. We further show that this phototropin-independent phototropic response to UV-B requires the UVoB photoreceptor UVR8. Broad UV-B-mediated repression of auxin-responsive genes suggests that UVR8 regulates directional bending by affecting auxin signaling. Kinetic analysis shows that UVR8-dependent directional bending occurs later than the phototropin response. We conclude that plants may use the full short-wavelength spectrum of sunlight to efficiently reorient photosynthetic tissue with incoming light.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0502)the National Natural Science Foundation of China(No.32370405).
文摘The phytohormone jasmonate(JA)coordinates stress and growth responses to increase plant survival in unfavorable environments.Although JA can enhance plant UV-B stress tolerance,the mechanisms underlying the interaction of UV-B and JA in this response remain unknown.In this study,we demonstrate that the UV RESISTANCE LOCUS 8-TEOSINTE BRANCHED1,Cycloidea and PCF 4-LIPOXYGENASE2(UVR8-TCP4-LOX2)module regulates UV-B tolerance dependent on JA signaling pathway in Arabidopsis thaliana.We show that the nucleus-localized UVR8 physically interacts with TCP4 to increase the DNA-binding activity of TCP4 and upregulate the JA biosynthesis gene LOX2.Furthermore,UVR8 activates the expression of LOX2 in a TCP4-dependent manner.Our genetic analysis also provides evidence that TCP4 acts downstream of UVR8 and upstream of LOX2 to mediate plant responses to UV-B stress.Our results illustrate that the UV-B-dependent interaction of UVR8 and TCP4 serves as an important UVR8-TCP4-LOX2 module,which integrates UV-B radiation and JA signaling and represents a new UVR8 signaling mechanism in plants.
文摘As one of the most important environmental signals for plants,light plays a profound role in regulating virtually every aspect of plant growth and development.Light signals are perceived by plants via several families of photoreceptors,among which phytochromes are responsible for absorbing the red(R)and far-red(FR)wavelengths(600–750 nm),cryptochromes(CRYs)perceive the blue(B)/ultraviolet-A(UV-A)wavelengths(320–500 nm),and UV RESISTANCE LOCUS 8(UVR8)is a recently-characterized UV-B(280–320 nm)photoreceptor.
文摘Plant UV-B responses are mediated by the photoreceptor UV RESISTANCE LOCUS 8 (UVR8). In re-sponse to UV-B irradiation, UVR8 homodimers dissociate into monomers that bind to the E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1). The in-teraction of the C27 domain in the C-terminal tail of UVR8 with the WD40 domain of COP1 is critical for UV-B sig-naling. However, the function of the last 17 amino acids (C17) of the C-terminus of UVR8, which are adjacent to C27, is unknown, although they are largely conserved in land plants. In this study, we established that Arabidopsis thaliana UVR8 C17 binds to full-length UVR8, but not to COP1, and reduces COP1 binding to the remaining portion of UVR8, including C27. We hypothesized that overexpression of C17 in a wild-type background would have a dominant negative effect on UVR8 activity;however, C17 overexpression caused strong silencing of endogenous UVR8, precluding a detailed analysis. We therefore generated YFP-UVR8N423 transgenic lines, in which C17 was deleted, to examine C17 function in-directly. YFP-UVR8N423 was more active than YFP-UVR8, suggesting that C17 inhibits UV-B signaling by attenuating binding between C27 and COP1. Our study reveals an inhibitory role for UVR8 C17 in fine-tuning UVR8–COP1 interactions during UV-B signaling.
基金supported by funds from the National Key R&D Program of China(2018YFA0507700 and 2017YFA0506100)the National Natural Science Foundation of China(31722017,31870753,and 32122011)+1 种基金the Foundation of Hubei Hongshan Laboratory(2021hszd010)the China Postdoctoral Science Foundation(2020M682437 for Ling Ma).
文摘The plant UV-B photoreceptor UV RESISTANCE LOCUS 8(UVR8)exists as a homodimer in its inactive ground state.Upon UV-B exposure,UVR8monomerizes and interacts with a downstreamkey regulator,theCONSTITUTIVE PHOTOMORPHOGENIC 1/SUPPRESSOR OF PHYA(COP1/SPA)E3 ubiquitin ligase complex,to initiate UV-B signaling.Two WD40 proteins,REPRESSOR OF UV-B PHOTOMORPHOGENESIS 1(RUP1)and RUP2 directly interact with monomeric UVR8 and facilitate UVR8 ground state reversion,completing the UVR8 photocycle.Here,we reconstituted the RUP-mediated UVR8 redimerization process in vitro and reported the structure of the RUP2-UVR8^(W285A) complex(2.0A).RUP2 and UVR8^(W285A) formed a heterodimer via two distinct interfaces,designated Interface 1 and 2.The previously characterized Interface 1 is found between the RUP2 WD40 domain and the UVR8 C27 subregion.The newly identified Interface 2 is formed through interactions between the RUP2 WD40 domain and the UVR8 core domain.Disruption of Interface 2 impairedUV-B induced photomorphogenic development in Arabidopsis thaliana.Further biochemical analysis indicated that both interfaces are important for RUP2-UVR8 interactions and RUP2-mediated facilitation of UVR8 redimerization.Our findings suggest that the two-interface-interaction mode is adopted by both RUP2 and COP1 when they interact with UVR8,marking a step forward in understanding the molecular basis that underpins the interactions between UVR8 and its photocycle regulators.
基金supported by the National Natural Science Foundation of China(32122011)the Fundamental Research Funds for the Central Universities(20720220142).
文摘Ultraviolet-B(UV-B)light is an intrinsic part of sunlight that reaches the earth’s surface,and affects plant survival and adaptation.How plants respond to UV-B light is regulated by the wavelength,intensity and duration of UV-B radiation,and is also regulated by photosynthetically active radiation perceived by phytochrome and cryptochrome photore-ceptors.Non-damaging UV-B light promotes plant photomorphogenesis and UV-B acclimation which enhances plant tolerance against UV-B stress.However,high-level UV-B radiation induces DNA damage,generates reactive oxygen species(ROS)and impairs photosynthesis.Plants have evolved efficient mechanisms to utilize informational UV-B signal,and protect themselves from UV-B stress.UV RESISTANCE LOCUS8(UVR8)is a conserved plant-specific UV-B photoreceptor.It interacts with CONSTITUTIVELY PHOTOMORPHOGENIC1(COP1)to initiate UV-B-specific light signal-ing and regulate UV-B responsive gene expression.A set of transcription factors such as ELONGATED HYPOCOTYL5(HY5)function downstream of the UVR8-COP1 module to promote seedling de-etiolation for photomorphogenic development and biosynthesis of sunscreen flavonoids for UV-B stress tolerance.In addition to UVR8 signaling path-ways,plants subjected to damaging UV-B radiation initiate stress protection and repair mechanisms through UVR8-independent pathways.In this review,we summarize the emerging mechanisms underlying UV-B stress acclimation and protection in plants,primarily revealed in the model plant Arabidopsis thaliana.
文摘Plants have evolved and perfected a series of light receptors to feel the light at different bands and regulate the expression, modification and interaction of related genes in plants through signal transduction. So far, many photoreceptors have been identified in plants, UVR8 has recently been identified as a receptor for UV-B light. This paper cloned a WD40 gene related to UVR8 protein subunit, named RrRUP2, based on the Rosa rugose transcriptome data, using Rosa rugose “Zi zhi” as experimental materials. The full length of cDNA of the gene was obtained by RT-PCR and RACE methods. The total length of this gene is 1173 bp, and it encodes 390 amino acids. After bioinformatics analysis, the molecular formula C3415H5659N1173O1434S313 was predicted;the relative molecular weight was 96129.27 Da;the theoretical isoelectric point PI value was 5.00;and its instability index was 47.06. The total average hydrophobic index was 0.750. In the secondary structure of RrRUP2 protein, there are 10 α-helix, 45 β-helix, 181 Random coil, and 154 Extended strand. Gene Bank Blast results showed that the amino acid sequence encoded by RrRUP2 was more than 90% homologous with the RUP2 protein of Rosa chinensis, Fragaria, Malus, Pyrus, Prunus, Juglans, Arabidopsis and Tobacco, so it can be inferred that the RrRUP2 gene is a WD repeat-containing protein. Regarding to fluorescence quantitative expression analysis of RrRUP2, we find its experssion pattern is corresponded with the accumulation of anthocyanins.
基金supported by grants from the National Key R&D Program of China(2016YFA0502900 and 2017YFA0506100)the National Natural Science Foundation(32070266)the Fundamental Research Funds for the Central Universities(20720190085).
文摘Decades of genetic,molecular and biochemical studies in plants have provided foundational knowledge about light sensory proteins and led to their application in synthetic biology.Optogenetic tools take advantage of the light switchable activity of plant photoreceptors to control intracellular signaling pathways.The recent discovery of the UV-B photoreceptor UV RESISTANCE LOCUS 8 in the model plant Arabidopsis thaliana opens up new avenues for light-controllable methodologies.In this review,we discuss current developments in optogenetic control by UV-B light and its signaling components,as well as rational considerations in the design and applications of UV-B-based optogenetic tools.
文摘【目的】获得雨生红球藻中紫外抗性蛋白(Uvresistance locus 8,UVR8)的cDNA序列全长,并进行生物信息分析。【方法】以雨生红球藻为研究对象,通过同源克隆方法获得紫外抗性蛋白UVR8的cDNA序列全长,并通过生物信息手段对其理化性质、蛋白结构及系统进化进行分析。【结果】序列分析表明,HaeUVR8的编码区全长为1554 bp,共编码517个氨基酸,预测理论等电点为5.56,理论分子量为54.31 kD。通过BLASTp分析,与拟南芥中UVR8的相似性达到51%,与莱菌衣藻中UVR8的相似性达到59%。通过蛋白保守结构域分析,HaeUVR8蛋白中存在UVR8蛋白的典型结构域,包括7个叶片螺旋结构和保守的色氨酸残基。系统进化分析表明,高等植物和真核绿藻来源UVR8s有共同祖先。【结论】本研究首次获得雨生红球藻中编码UVR8的基因序列,发现其结构与高等植物UVR8相似,暗示二者可能有相似的作用机制,为雨生红球藻中UVR8的表达、功能研究奠定基础,同时为解析雨生红球藻适应紫外光的分子机制提供线索。
