Plant shoot phototropism is triggered by the formation of a light-driven auxin gradient leading to bending growth.The blue light receptor phototropin 1(phot1)senses light direction,but how this leads to auxin gradient...Plant shoot phototropism is triggered by the formation of a light-driven auxin gradient leading to bending growth.The blue light receptor phototropin 1(phot1)senses light direction,but how this leads to auxin gradient formation and growth regulation remains poorly understood.Previous studies have suggested phot1’s role for regulated apoplastic acidification,but its relation to phototropin and hypocotyl phototropism is unclear.Herein,we show that blue light can cause phot1 to interact with and phosphorylate FERONIA(FER),a known cell growth regulator,and trigger downstream phototropic bending growth in Arabidopsis hypocotyls.fer mutants showed defects in phototropic growth,similar to phot1/2 mutant.FER also interacts with and phosphorylates phytochrome kinase substrates,the phot1 downstream substrates.The phot1-FER pathway acts upstream of apoplastic acidification and the auxin gradient formation in hypocotyl under lateral blue light,both of which are critical for phototropic bending growth in hypocotyls.Our study highlights a pivotal role of FER in the phot1-mediated phototropic cell growth regulation in plants.展开更多
The phototropins phot1 and phot2 are plant blue-light receptors that mediate phototropism, chloroplast movements, stomatal opening, leaf expansion, the rapid Inhibition of hypocotyl growth in etiolated seedlings, and ...The phototropins phot1 and phot2 are plant blue-light receptors that mediate phototropism, chloroplast movements, stomatal opening, leaf expansion, the rapid Inhibition of hypocotyl growth in etiolated seedlings, and possibly solar tracking by leaves in those species in which It occurs. The phototroplns are plasma membrane-associated hydrophilic proteins with two chromophore domains （designated LOV1 and LOV2 for their resemblance to domains In other signaling proteins that detect light, oxygen, or voltage） in their Nterminal half and a classic serine/threonlne kinase domain in their C-terminal half. Both chromophore domains bind flavin mononucleotide （FMN） and both undergo light-activated formation of a covalent bond between a nearby cystelne and the C（4a） carbon of the FMN to form the signaling state. LOV2-cystelnyl adduct formation leads to the release downstream of a tightly bound amphlpathlc α-helix, a step required for activation of the klnase function. This cysteinyl adduct then slowly decays over a matter of seconds or minutes to return the photoreceptor chromophore modules to their ground state. Functional LOV2 is required for light-activated phosphorylation and for various blue-light responses mediated by the phototroplns. The function of LOV1 is still unknown, although It may serve to modulate the signal generated by LOV2. The LOV domain Is an ancient chromophore module found In a wide range of otherwise unrelated proteins In fungi and prokaryotes, the latter Including cyanobacterla, eubacterla, and archaea. Further general reviews on the phototropins are those by Celaya and Liscum （2005） and Christie and Briggs （2005）.展开更多
To cope with fluctuating light conditions,terrestrial plants have evolved precise regulation mechanisms to help optimize light capture and increase photosynthetic efficiency.Upon blue light-triggered autophosphorylati...To cope with fluctuating light conditions,terrestrial plants have evolved precise regulation mechanisms to help optimize light capture and increase photosynthetic efficiency.Upon blue light-triggered autophosphorylation,acti-vated phototropin(PHOT1 and PHOT2)photoreceptors function solely or redundantly to regulate diverse responses,including phototropism,chloroplast movement,stomatal opening,and leaf positioning and flattening in plants.These responses enhance light capture under low-light conditions and avoid photodamage under high-light conditions.NON-PHOTOTROPIC HYPOCOTYL 3(NPH3)and ROOT PHOTOTROPISM 2(RPT2)are signal transducers that function in the PHOT1-and PHOT2-mediated response.NPH3 is required for phototropism,leaf expansion and positioning.RPT2 regulates chloroplast accumulation as well as NPH3-mediated responses.NRL PROTEIN FOR CHLOROPLAST MOVE-MENT 1(NCH1)was recently identified as a PHOT1-interacting protein that functions redundantly with RPT2 to medi-ate chloroplast accumulation.The PHYTOCHROME KINASE SUBSTRATE(PKS)proteins(PKS1,PKS2,and PKS4)interact with PHOT1 and NPH3 and mediate hypocotyl phototropic bending.This review summarizes advances in phototropic growth and chloroplast movement induced by light.We also focus on how crosstalk in signaling between phototro-pism and chloroplast movement enhances weak light capture,providing a basis for future studies aiming to delineate the mechanism of light-trapping plants to improve light-use efficiency.展开更多
基金supported by grants from the National Natural Science Foundation of China(NSFC-31571444,31871396,31900392,31972913,82101246)Hunan Provincial Natural Science Foundation of China(2021JJ30799,2021JJ40813)+2 种基金the China Postdoctoral Science Foundation(2019M652793,2021T140753)the Open Research Fund(2016KF03)of the State Key Laboratory of Hybrid Rice(Hunan Hybrid Rice Research Center)the Fundamental Research Funds for the Central Universities of China(Hunan University,No.531107050967)。
文摘Plant shoot phototropism is triggered by the formation of a light-driven auxin gradient leading to bending growth.The blue light receptor phototropin 1(phot1)senses light direction,but how this leads to auxin gradient formation and growth regulation remains poorly understood.Previous studies have suggested phot1’s role for regulated apoplastic acidification,but its relation to phototropin and hypocotyl phototropism is unclear.Herein,we show that blue light can cause phot1 to interact with and phosphorylate FERONIA(FER),a known cell growth regulator,and trigger downstream phototropic bending growth in Arabidopsis hypocotyls.fer mutants showed defects in phototropic growth,similar to phot1/2 mutant.FER also interacts with and phosphorylates phytochrome kinase substrates,the phot1 downstream substrates.The phot1-FER pathway acts upstream of apoplastic acidification and the auxin gradient formation in hypocotyl under lateral blue light,both of which are critical for phototropic bending growth in hypocotyls.Our study highlights a pivotal role of FER in the phot1-mediated phototropic cell growth regulation in plants.
基金Supported by the National Science Foundation, USA, grants MCB 0091384 and 0444504 to WRB, MCB0444390 to RAB, and by the UK Biotechnology and Biological Sciences Research Council, grant BB/C000366/1 to JMC. Publication of this paper is supported by the National Natural Science Foundation of China （30624808） and Science Publication Foundation of the Chinese Academy of Sciences.
文摘The phototropins phot1 and phot2 are plant blue-light receptors that mediate phototropism, chloroplast movements, stomatal opening, leaf expansion, the rapid Inhibition of hypocotyl growth in etiolated seedlings, and possibly solar tracking by leaves in those species in which It occurs. The phototroplns are plasma membrane-associated hydrophilic proteins with two chromophore domains （designated LOV1 and LOV2 for their resemblance to domains In other signaling proteins that detect light, oxygen, or voltage） in their Nterminal half and a classic serine/threonlne kinase domain in their C-terminal half. Both chromophore domains bind flavin mononucleotide （FMN） and both undergo light-activated formation of a covalent bond between a nearby cystelne and the C（4a） carbon of the FMN to form the signaling state. LOV2-cystelnyl adduct formation leads to the release downstream of a tightly bound amphlpathlc α-helix, a step required for activation of the klnase function. This cysteinyl adduct then slowly decays over a matter of seconds or minutes to return the photoreceptor chromophore modules to their ground state. Functional LOV2 is required for light-activated phosphorylation and for various blue-light responses mediated by the phototroplns. The function of LOV1 is still unknown, although It may serve to modulate the signal generated by LOV2. The LOV domain Is an ancient chromophore module found In a wide range of otherwise unrelated proteins In fungi and prokaryotes, the latter Including cyanobacterla, eubacterla, and archaea. Further general reviews on the phototropins are those by Celaya and Liscum （2005） and Christie and Briggs （2005）.
文摘【目的】本文旨在获得雨生红球藻中蓝光受体向光素(Phototropin,PHOT)的全长序列并进行生物信息分析。【方法】采用同源克隆和RACE结合的方法获得雨生红球藻中编码HaePHOT的c DNA序列全长,并对HaePHOT进行生物信息分析。【结果】HaePHOT的开放阅读框全长为2139 bp,编码712个氨基酸,预测的等电点8.66,理论分子量78.73 k D。经BLASTP程序分析,与拟南芥来源PHOT的相似性达到58%,与莱茵衣藻来源PHOT的相似性达到68%。通过序列比对和结构域分析,PHOT蛋白的典型结构域存在于HaePHOT中,包括发色团结合和激酶结构域。系统进化分析表明,高等植物和真核绿藻来源PHOTs来自共同祖先。【结论】首次从雨生红球藻中获得编码PHOT的基因序列,为下一步雨生红球藻中PHOT的表达和功能研究奠定基础,同时为解析蓝光调控雨生红球藻虾青素合成的分子机制提供线索。
基金support from the National Natural Science Foundation of China(grant nos.31871419,and 31570294)Central Plain Talent Scheme(Grants.ZYYCYU202012164)by the Program for Innovative Research Team(in Science and Technology)in University of Henan Province(Grants.21IRTSTHN019).
文摘To cope with fluctuating light conditions,terrestrial plants have evolved precise regulation mechanisms to help optimize light capture and increase photosynthetic efficiency.Upon blue light-triggered autophosphorylation,acti-vated phototropin(PHOT1 and PHOT2)photoreceptors function solely or redundantly to regulate diverse responses,including phototropism,chloroplast movement,stomatal opening,and leaf positioning and flattening in plants.These responses enhance light capture under low-light conditions and avoid photodamage under high-light conditions.NON-PHOTOTROPIC HYPOCOTYL 3(NPH3)and ROOT PHOTOTROPISM 2(RPT2)are signal transducers that function in the PHOT1-and PHOT2-mediated response.NPH3 is required for phototropism,leaf expansion and positioning.RPT2 regulates chloroplast accumulation as well as NPH3-mediated responses.NRL PROTEIN FOR CHLOROPLAST MOVE-MENT 1(NCH1)was recently identified as a PHOT1-interacting protein that functions redundantly with RPT2 to medi-ate chloroplast accumulation.The PHYTOCHROME KINASE SUBSTRATE(PKS)proteins(PKS1,PKS2,and PKS4)interact with PHOT1 and NPH3 and mediate hypocotyl phototropic bending.This review summarizes advances in phototropic growth and chloroplast movement induced by light.We also focus on how crosstalk in signaling between phototro-pism and chloroplast movement enhances weak light capture,providing a basis for future studies aiming to delineate the mechanism of light-trapping plants to improve light-use efficiency.
