Precise spatiotemporal control of the timing and extent of asymmetric cell divisions(AcDs)is essential for plant development.In the Arabidopsis root,ground tissue maturation involves an additional AcD of the endo-derm...Precise spatiotemporal control of the timing and extent of asymmetric cell divisions(AcDs)is essential for plant development.In the Arabidopsis root,ground tissue maturation involves an additional AcD of the endo-dermis that maintains the inner cell layer as the endodermis and generates the middle cortex to the outside.Through regulation of the cell cycle regulator CYCLIND6;1(CYCD6;1),the transcription factors SCARECROW(SCR)and SHORT-ROOT(SHR)play critical roles in this process.In the present study,we found that loss of function of NAC1,a NAC transcription factor family gene,causes markedly increased periclinal cell divisions in the root endodermis.Importantly,NAC1 directly represses the transcription of CYCD6;1 by recruiting the co-repressor TOPLESS(TPL),creating a fine-tuned mechanism to maintain proper root ground tissue patterning by limiting production of middle cortex cells.Biochemical and genetic analyses further showed that NAC1 physically interacts with SCR and SHR to restrict excessive periclinal cell divisions in the endo-dermis during root middle cortex formation.Although NAC1-TPL is recruited to the CYCD6;1 promoter and represses its transcription in an SCR-dependent manner,NAC1 and SHR antagonize each other to regu-late the expression of CYCD6;1.Collectively,our study provides mechanistic insights into how the NAC1-TPL module integrates with the master transcriptional regulators SCR and SHR to control root ground tissue patterning by fine-tuning spatiotemporal expression of CYCD6;1 in Arabidopsis.展开更多
基金supported by the National Natural Science Foundation of China(32170338 and 32061143005)Innovative Research Groups of Shandong University(2020QNQT014)+3 种基金the Shandong Province Natural Science Foundation of the Major Basic Research Program(2017C03)(to Z.D.)by the National Natural Science Foundation of China(32170311 and 31970192)the Shandong Province Funds for Excellent Young Scholars(ZR2020YQ19)the Program of Shandong University Qilu Young Scholars(to X.K.).
文摘Precise spatiotemporal control of the timing and extent of asymmetric cell divisions(AcDs)is essential for plant development.In the Arabidopsis root,ground tissue maturation involves an additional AcD of the endo-dermis that maintains the inner cell layer as the endodermis and generates the middle cortex to the outside.Through regulation of the cell cycle regulator CYCLIND6;1(CYCD6;1),the transcription factors SCARECROW(SCR)and SHORT-ROOT(SHR)play critical roles in this process.In the present study,we found that loss of function of NAC1,a NAC transcription factor family gene,causes markedly increased periclinal cell divisions in the root endodermis.Importantly,NAC1 directly represses the transcription of CYCD6;1 by recruiting the co-repressor TOPLESS(TPL),creating a fine-tuned mechanism to maintain proper root ground tissue patterning by limiting production of middle cortex cells.Biochemical and genetic analyses further showed that NAC1 physically interacts with SCR and SHR to restrict excessive periclinal cell divisions in the endo-dermis during root middle cortex formation.Although NAC1-TPL is recruited to the CYCD6;1 promoter and represses its transcription in an SCR-dependent manner,NAC1 and SHR antagonize each other to regu-late the expression of CYCD6;1.Collectively,our study provides mechanistic insights into how the NAC1-TPL module integrates with the master transcriptional regulators SCR and SHR to control root ground tissue patterning by fine-tuning spatiotemporal expression of CYCD6;1 in Arabidopsis.
