Light is arguably one of the most important environmental factors that determines virtually all aspects of plant growth and development,but the molecular link between light signaling and the autophagy pathway has not ...Light is arguably one of the most important environmental factors that determines virtually all aspects of plant growth and development,but the molecular link between light signaling and the autophagy pathway has not been elucidated in plants.In this study,we demonstrate that autophagy is activated during light-to-dark conversion though transcriptional upregulation of autophagy-related genes(ATGs).We showed that depletion of the ELONGATED HYPOCOTYL 5(HY5),a key component of light signaling,leads to enhanced autophagy activity and resistance to extended darkness and nitrogen starvation treatments,contributing to higher expression oiATGs.HY5 interacts with and recruits HISTONE DEACETYLASE 9(HDA9)to ATG5 and ATG8e loci to repress their expression by deacetylation of the Lys9 and Lys27 of histone 3.Furthermore,we found that both darkness and nitrogen depletion induce the degradation of HY5 via 26S proteasome and the concomitant disassociation of HDA9 from ATG5 and ATG8e loci,leading to their depression and thereby activated autophagy.Genetic analysis further confirmed that HY5 and HDA9 act synergistically and function upstream of the autophagy pathway.Collectively,our study unveils a previously unknown transcriptional and epigenetic network that regulates autophagy in response to light-to-dark conversion and nitrogen starvation in plants.展开更多
Epigenetic regulation of gene expression is important for plant adaptation to environm ental changes.Previous results showed that Arabidopsis RPD3-like histone deacetylase HDA9 is known to function in repressing plant...Epigenetic regulation of gene expression is important for plant adaptation to environm ental changes.Previous results showed that Arabidopsis RPD3-like histone deacetylase HDA9 is known to function in repressing plant response to stress in Arabidopsis.However,how HDA9 targets to specific chromatin loci and controls gene expression netw orks involved in plant response to stress remains largely unclear.Here,we show that HDA9 represses stress tolerance response by interacting with and regulating the DNA binding and transcriptional activity of WRKY53,which functions as a high-hierarchy positive regulator of stress response.We found that WRKY53 is post-translationally modified by lysine acetylation at multiple sites,some of which are removed by HDA9,resulting in inhibition of WRKY53 transcription activity.Conversely,WRKY53 negatively regulates HDA9 histone deacetylase activity.Collectively,our results indicate that HDA9 and WRK53 are reciprocal negative regulators of each other's activities,illustrating how the functional interplay between a chromatin regulator and a transcription factor regulates stress tolerance in plants.展开更多
Integration of light signaling and diverse abiotic stress responses contribute to plant survival in a changing environment.Some reports have indicated that light signals contribute a plant’s ability to deal with heat...Integration of light signaling and diverse abiotic stress responses contribute to plant survival in a changing environment.Some reports have indicated that light signals contribute a plant’s ability to deal with heat,cold,and stress.However,the molecular link between light signaling and the saltresponse pathways remains unclear.We demonstrate here that increasing light intensity elevates the salt stress tolerance of plants.Depletion of HY5,a key component of light signaling,causes Arabidopsis thaliana to become salinity sensitive.Interestingly,the small heat shock protein(sHsp)family genes are upregulated in hy5-215 mutant plants,and HsfA 2 is commonly involved in the regulation of these sH sps.We found that HY5directly binds to the G-box motifs in the HsfA2promoter,with the cooperation of HISTONE DEACETYLASE 9(HDA9),to repress its expression.Furthermore,the accumulation of HDA9 and the interaction between HY5 and HDA9 are significantly enhanced by salt stress.On the contrary,high temperature triggers HY5 and HDA9 degradation,which leads to dissociation of HY5-HDA9from the HsfA2 promoter,thereby reducing salt tolerance.Under salt and heat stress conditions,fine tuning of protein accumulation and an interaction between HY5 and HDA9 regulate HsfA2 expression.This implies that HY5,HDA9,and HsfA2play important roles in the integration of light signaling with salt stress and heat shock response.展开更多
Phototropism is essential for optimizing plant growth and development,with the blue light receptor phototropin 1(phot1)acting as the primary photoreceptor.Although downstream components of phot1mediated phototropic si...Phototropism is essential for optimizing plant growth and development,with the blue light receptor phototropin 1(phot1)acting as the primary photoreceptor.Although downstream components of phot1mediated phototropic signaling have been studied extensively,the upstream regulatory mechanisms that control phot1 activity remain to be clarified.Here,we demonstrate that lysine acetylation dynamically modifies phot1 under both dark and light conditions.Site-directed mutagenesis of acetylated lysines revealed that acetylation regulates the light-induced autophosphorylation and kinase activity of phot1.Genetic screening of histone deacetylase(HDAC)mutants identified HDA9 as a key regulator of phototropism that physically interacts with phot1,modulating its acetylation and phosphorylation levels in response to light.We pinpointed K636 as the critical acetylation site targeted by HDA9,linking deacetylation to phot1 activation.Our findings reveal a regulatory paradigm in which HDA9-mediated deacetylation fine-tunes the phosphorylation dynamics of phot1 to control phototropic responses.This acetylation-phosphorylation crosstalk appears to be evolutionarily conserved,underscoring its broad significance in light signaling.Our study provides insight into the mechanisms by which antagonistic post-translational modifications precisely regulate photoreceptor sensitivity and signal transduction in plants.展开更多
基金supported by grants from the National Natural Science Foundation of China(31900231)National Science Foundation of Guangdong Province(2018A030310505)to C.Y.+3 种基金the National Natural Science Foundation of China(31870171 and 31671467),toC.G.the Youth Innovation Promotion Association,Chinese Academy of Sciences(2017399)the National Key R&D Program of China(2019YFC1711102)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA13020500)to M.L.,and the National Natural Science Foundation of China(31701246)to W.S.
文摘Light is arguably one of the most important environmental factors that determines virtually all aspects of plant growth and development,but the molecular link between light signaling and the autophagy pathway has not been elucidated in plants.In this study,we demonstrate that autophagy is activated during light-to-dark conversion though transcriptional upregulation of autophagy-related genes(ATGs).We showed that depletion of the ELONGATED HYPOCOTYL 5(HY5),a key component of light signaling,leads to enhanced autophagy activity and resistance to extended darkness and nitrogen starvation treatments,contributing to higher expression oiATGs.HY5 interacts with and recruits HISTONE DEACETYLASE 9(HDA9)to ATG5 and ATG8e loci to repress their expression by deacetylation of the Lys9 and Lys27 of histone 3.Furthermore,we found that both darkness and nitrogen depletion induce the degradation of HY5 via 26S proteasome and the concomitant disassociation of HDA9 from ATG5 and ATG8e loci,leading to their depression and thereby activated autophagy.Genetic analysis further confirmed that HY5 and HDA9 act synergistically and function upstream of the autophagy pathway.Collectively,our study unveils a previously unknown transcriptional and epigenetic network that regulates autophagy in response to light-to-dark conversion and nitrogen starvation in plants.
基金This study was supported by the Discipline Innovation Team Foundation of Jianghan University(03100074)Natural Science Foundation of Hubei Province(grant no.2016CFB630)+1 种基金National Natural Science Foundation of China(NSFC31701100,NSFC31600981,and NSFC31600801)French ANR-19-CE12-0027-01.
文摘Epigenetic regulation of gene expression is important for plant adaptation to environm ental changes.Previous results showed that Arabidopsis RPD3-like histone deacetylase HDA9 is known to function in repressing plant response to stress in Arabidopsis.However,how HDA9 targets to specific chromatin loci and controls gene expression netw orks involved in plant response to stress remains largely unclear.Here,we show that HDA9 represses stress tolerance response by interacting with and regulating the DNA binding and transcriptional activity of WRKY53,which functions as a high-hierarchy positive regulator of stress response.We found that WRKY53 is post-translationally modified by lysine acetylation at multiple sites,some of which are removed by HDA9,resulting in inhibition of WRKY53 transcription activity.Conversely,WRKY53 negatively regulates HDA9 histone deacetylase activity.Collectively,our results indicate that HDA9 and WRK53 are reciprocal negative regulators of each other's activities,illustrating how the functional interplay between a chromatin regulator and a transcription factor regulates stress tolerance in plants.
基金supported by the Talents Project of Henan Agricultural University (30601733)International Training Program for high-level Talents of Henan Province (30602056)。
文摘Integration of light signaling and diverse abiotic stress responses contribute to plant survival in a changing environment.Some reports have indicated that light signals contribute a plant’s ability to deal with heat,cold,and stress.However,the molecular link between light signaling and the saltresponse pathways remains unclear.We demonstrate here that increasing light intensity elevates the salt stress tolerance of plants.Depletion of HY5,a key component of light signaling,causes Arabidopsis thaliana to become salinity sensitive.Interestingly,the small heat shock protein(sHsp)family genes are upregulated in hy5-215 mutant plants,and HsfA 2 is commonly involved in the regulation of these sH sps.We found that HY5directly binds to the G-box motifs in the HsfA2promoter,with the cooperation of HISTONE DEACETYLASE 9(HDA9),to repress its expression.Furthermore,the accumulation of HDA9 and the interaction between HY5 and HDA9 are significantly enhanced by salt stress.On the contrary,high temperature triggers HY5 and HDA9 degradation,which leads to dissociation of HY5-HDA9from the HsfA2 promoter,thereby reducing salt tolerance.Under salt and heat stress conditions,fine tuning of protein accumulation and an interaction between HY5 and HDA9 regulate HsfA2 expression.This implies that HY5,HDA9,and HsfA2play important roles in the integration of light signaling with salt stress and heat shock response.
基金funded by grants from the National Natural Science Foundation of China(32371326,32070551,and 32101342)the Guangdong Science and Technology Plan Project(2023B1212060046)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(2020A1515110711)the Guangdong Provincial Key Laboratory of Plant Resource(2019PlantKF08).
文摘Phototropism is essential for optimizing plant growth and development,with the blue light receptor phototropin 1(phot1)acting as the primary photoreceptor.Although downstream components of phot1mediated phototropic signaling have been studied extensively,the upstream regulatory mechanisms that control phot1 activity remain to be clarified.Here,we demonstrate that lysine acetylation dynamically modifies phot1 under both dark and light conditions.Site-directed mutagenesis of acetylated lysines revealed that acetylation regulates the light-induced autophosphorylation and kinase activity of phot1.Genetic screening of histone deacetylase(HDAC)mutants identified HDA9 as a key regulator of phototropism that physically interacts with phot1,modulating its acetylation and phosphorylation levels in response to light.We pinpointed K636 as the critical acetylation site targeted by HDA9,linking deacetylation to phot1 activation.Our findings reveal a regulatory paradigm in which HDA9-mediated deacetylation fine-tunes the phosphorylation dynamics of phot1 to control phototropic responses.This acetylation-phosphorylation crosstalk appears to be evolutionarily conserved,underscoring its broad significance in light signaling.Our study provides insight into the mechanisms by which antagonistic post-translational modifications precisely regulate photoreceptor sensitivity and signal transduction in plants.
