Circadian clock regulates Glc-TOR signaling to modulate root meristem activity through Pseudo Response Regulators proteins in Arabidopsis

【作者】 李彬； 王岩； 张媛媛； 田文文； 王雷；

【Author】 Bin Li;Yan Wang;Yuanyuan Zhang;Wenwen Tian;Lei Wang;

【机构】 中国科学院植物研究所植物分子生理重点实验室；

【摘要】 Circadian clocks are ubiquitous biochemical time-keeping mechanisms and provide an adaptive advantage to high plants,while the eukaryote evolutionary conserved TOR signaling promotes cell proliferation and growth by integrating endogenous nutrition and energy status.The intersection between circadian clock and Glc-TOR signaling and its molecular mechanism in higher plants remain elusive.Here we found that Pseudo Response Regulators,the crucial components of plant core oscillator,modulate Glc-TOR signaling redundantly to affect cell division acitivity in root meristem.The PRR mutants displayed diminished Glc-TOR signaling with reduced cell division in root meristem,correspondingly with reduced TOR,E2 Fa and S1-phase genes message RNA level in prr579 triple mutant.Furthermore,we dissected a RNA-binding protein,Tandem Zinc Finger 1,is the direct target of PRR proteins and acts as the key downstream component of PRRs to modulate TOR signaling.PRR proteins can bind to the promoter of TZF1 to repress its transcription,while TZF1 overexpression displays reduced TOR signaling but not feedback regulate circadian itself.Thus,our findings established that PRR-TZF1 module specifically acts circadian outputs to modulate cell division in root meristem by affecting TOR signaling.Moreover,we found chemical inhibition of TOR signaling by AZD0085 shortens circadian period.Collectively,our findings discovered the closely intersection between circadian clock and TOR signaling,the two crucial cellular coordination mechanism for plant fitness and growth,and implicated circadian clock is able to regulate cell division,at least in root meristem.更多还原

【Abstract】 Circadian clocks are ubiquitous biochemical time-keeping mechanisms and provide an adaptive advantage to high plants,while the eukaryote evolutionary conserved TOR signaling promotes cell proliferation and growth by integrating endogenous nutrition and energy status.The intersection between circadian clock and Glc-TOR signaling and its molecular mechanism in higher plants remain elusive.Here we found that Pseudo Response Regulators,the crucial components of plant core oscillator,modulate Glc-TOR signaling redundantly to affect cell division acitivity in root meristem.The PRR mutants displayed diminished Glc-TOR signaling with reduced cell division in root meristem,correspondingly with reduced TOR,E2 Fa and S1-phase genes message RNA level in prr579 triple mutant.Furthermore,we dissected a RNA-binding protein,Tandem Zinc Finger 1,is the direct target of PRR proteins and acts as the key downstream component of PRRs to modulate TOR signaling.PRR proteins can bind to the promoter of TZF1 to repress its transcription,while TZF1 overexpression displays reduced TOR signaling but not feedback regulate circadian itself.Thus,our findings established that PRR-TZF1 module specifically acts circadian outputs to modulate cell division in root meristem by affecting TOR signaling.Moreover,we found chemical inhibition of TOR signaling by AZD0085 shortens circadian period.Collectively,our findings discovered the closely intersection between circadian clock and TOR signaling,the two crucial cellular coordination mechanism for plant fitness and growth,and implicated circadian clock is able to regulate cell division,at least in root meristem.更多还原