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
BACKGROUND： Phototropism is the response a plant exhibits when it is faced with a directional blue light stimulus. Though a seemingly simple differential cell elongation response within a responding tissue that resul...BACKGROUND： Phototropism is the response a plant exhibits when it is faced with a directional blue light stimulus. Though a seemingly simple differential cell elongation response within a responding tissue that results in organ curvature, phototropism is regulated through a complex set of signal perception and transduction events that move from the plasma membrane to the nucleus. In nature phototropism is one of several plant responses that have evolved to optimize photosynthesis and growth. OBJECTIVE： In the present work we will review the state of the field with respect to the molecules and mechanisms associated with phototropism in land plants. METHODS： A systematic literature search was done to identify relevant advances in the field. Though we tried to focus on literature within the past decade （1998-present）, we have discussed and cited older literature where appropriate because of context or its significant impact to the present field. Several previous review articles are also cited where appropriate and readers should seek those out. RESULTS： A total of 199 articles are cited that fulfill the criteria listed above. CONCLUSIONS： Though important numerous and significant advances have been made in our understanding of the molecular, biochemical, cell biological and physiologic mechanisms underlying phototropism in land plants over the past decade, there are many remaining unanswered questions. The future is indeed bright for researchers in the field and we look forward to the next decade worth of discoveries.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.
文摘BACKGROUND： Phototropism is the response a plant exhibits when it is faced with a directional blue light stimulus. Though a seemingly simple differential cell elongation response within a responding tissue that results in organ curvature, phototropism is regulated through a complex set of signal perception and transduction events that move from the plasma membrane to the nucleus. In nature phototropism is one of several plant responses that have evolved to optimize photosynthesis and growth. OBJECTIVE： In the present work we will review the state of the field with respect to the molecules and mechanisms associated with phototropism in land plants. METHODS： A systematic literature search was done to identify relevant advances in the field. Though we tried to focus on literature within the past decade （1998-present）, we have discussed and cited older literature where appropriate because of context or its significant impact to the present field. Several previous review articles are also cited where appropriate and readers should seek those out. RESULTS： A total of 199 articles are cited that fulfill the criteria listed above. CONCLUSIONS： Though important numerous and significant advances have been made in our understanding of the molecular, biochemical, cell biological and physiologic mechanisms underlying phototropism in land plants over the past decade, there are many remaining unanswered questions. The future is indeed bright for researchers in the field and we look forward to the next decade worth of discoveries.
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.
