Plants can sense temperature changes and adjust their growth accordingly.In Arabidopsis,high ambient temperatures stimulate stem elongation by activating a key thermoresponsive regulator,PHYTOCHROME INTERACTING FACTOR...Plants can sense temperature changes and adjust their growth accordingly.In Arabidopsis,high ambient temperatures stimulate stem elongation by activating a key thermoresponsive regulator,PHYTOCHROME INTERACTING FACTOR 4(PIF4).Here,we show that warmth promotes the nighttime transcription of GI,which is necessary for the high temperature-induced transcription of TOC1.Genetic analyses suggest that GI prevents excessive thermoresponsive growth by inhibiting PIF4,with this regulatory mechanism be-ing partially reliant on TOC1.GI transcription is repressed by ELF3 and HY5,which concurrently inhibit PIF4 expression and activity.Temperature elevation causes the deactivation or degradation of ELF3 and HY5,leading to PIF4 activation and relief of GI transcriptional repression at high temperatures.This allows PIF4 to further activate GI transcription in response to elevated temperatures.GI,in turn,inhibits PIF4,es-tablishing a negative feedback loop thatfine-tunes PIF4 activity.In addition,we demonstrate that ELF3,HY5,and PIF4 regulate GI transcription by modulating the enrichment of histone variant H2A.Z at the GI lo-cus.Together,ourfindings suggest that thermal release of a negative feedback loopfinely adjusts plant thermomorphogenesis.展开更多
Extremely high or low autophagy levels disrupt plant survival under nutrient starvation.Recently,autophagy has been reported to display rhythms in animals.However,the mechanism of circadian regulation of autophagy is ...Extremely high or low autophagy levels disrupt plant survival under nutrient starvation.Recently,autophagy has been reported to display rhythms in animals.However,the mechanism of circadian regulation of autophagy is still unclear.Here,we observed that autophagy has a robust rhythm and that various autophagy-related genes(ATGs)are rhythmically expressed in Arabidopsis.Chromatin immunoprecipitation(Ch IP)and dual-luciferase(LUC)analyses showed that the core oscillator gene TIMING OF CAB EXPRESSION 1(TOC1)directly binds to the promoters of ATG(ATG1 a,ATG2,and ATG8 d)and negatively regulates autophagy activities under nutritional stress.Furthermore,autophagy defects might affect endogenous rhythms by reducing the rhythm amplitude of TOC1 and shortening the rhythm period of CIRCADIAN CLOCK-ASSOCIATED 1(CCA1).Autophagy is essential for the circadian clock pattern in seedling development and plant sensitivity to nutritional deficiencies.Taken together,our studies reveal a plant strategy in which the TOC1-ATG axis involved in autophagy-rhythm crosstalk to fine-tune the intensity of autophagy.展开更多
基金supported by the National Natural Science Foundation of China (32150610472)the National Key R&D Program of China (2019YFA0903903).
文摘Plants can sense temperature changes and adjust their growth accordingly.In Arabidopsis,high ambient temperatures stimulate stem elongation by activating a key thermoresponsive regulator,PHYTOCHROME INTERACTING FACTOR 4(PIF4).Here,we show that warmth promotes the nighttime transcription of GI,which is necessary for the high temperature-induced transcription of TOC1.Genetic analyses suggest that GI prevents excessive thermoresponsive growth by inhibiting PIF4,with this regulatory mechanism be-ing partially reliant on TOC1.GI transcription is repressed by ELF3 and HY5,which concurrently inhibit PIF4 expression and activity.Temperature elevation causes the deactivation or degradation of ELF3 and HY5,leading to PIF4 activation and relief of GI transcriptional repression at high temperatures.This allows PIF4 to further activate GI transcription in response to elevated temperatures.GI,in turn,inhibits PIF4,es-tablishing a negative feedback loop thatfine-tunes PIF4 activity.In addition,we demonstrate that ELF3,HY5,and PIF4 regulate GI transcription by modulating the enrichment of histone variant H2A.Z at the GI lo-cus.Together,ourfindings suggest that thermal release of a negative feedback loopfinely adjusts plant thermomorphogenesis.
基金supported by grants from the National Natural Science Foundation of China(NSFC–31871396,31571444)the Young Elite Scientist Sponsorship Program of CAST(YESS20160001)+3 种基金the Open Research Fund of the State Key Laboratory of Hybrid Rice(Hunan Hybrid Rice Research Center)to Feng Yuthe Foundation of Hunan Provincial Natural Science(2021JJ30540)the Foundation of Hunan Double First-rate Discipline Construction Projects of Bioengineering to Zhaotun Huthe China Tobacco Hunan Industrial Co.,Ltd.Research Project(KY2021YC0001)to W.X.P。
文摘Extremely high or low autophagy levels disrupt plant survival under nutrient starvation.Recently,autophagy has been reported to display rhythms in animals.However,the mechanism of circadian regulation of autophagy is still unclear.Here,we observed that autophagy has a robust rhythm and that various autophagy-related genes(ATGs)are rhythmically expressed in Arabidopsis.Chromatin immunoprecipitation(Ch IP)and dual-luciferase(LUC)analyses showed that the core oscillator gene TIMING OF CAB EXPRESSION 1(TOC1)directly binds to the promoters of ATG(ATG1 a,ATG2,and ATG8 d)and negatively regulates autophagy activities under nutritional stress.Furthermore,autophagy defects might affect endogenous rhythms by reducing the rhythm amplitude of TOC1 and shortening the rhythm period of CIRCADIAN CLOCK-ASSOCIATED 1(CCA1).Autophagy is essential for the circadian clock pattern in seedling development and plant sensitivity to nutritional deficiencies.Taken together,our studies reveal a plant strategy in which the TOC1-ATG axis involved in autophagy-rhythm crosstalk to fine-tune the intensity of autophagy.
