Genji Qin, Ph. D.
Plant leaf development and transcriptional regulation
Professor, College of Life Sciences, Peking University
tel：
E-mail：qingenji@pku.edu.cn
1.The molecular mechanisms of plant leaf development and the other organ development
2.The plant transcriptional regulation
The TIE1 transcriptional repressor regulates Arabidopsis leaf development. We discovered a novel gene TIE1 by forward genetics. TIE1 encodes an EAR-motif-containing protein and plays important roles in leaf development. Overexpression of TIE1 caused hyponastic and serrated leaves, whereas disruption of TIE1 led to epinastic leaves. We further uncovered a molecular framework by which TIE1 regulates leaf development. TIE1 is a transcription repressor recruits corepressor TPL/TPRs through its C-terminal EAR motif to repress the activities of the TCP (TEOSINTE BRANCHED1/CYCLOIDEA/PCF) family transcription factors that interact with the N-terminal domain of TIE1 during leaf development. We also identified a group of RING-type E3 ligases which regulates leaf development by targeting TIE1 for degradation.
SPOROCYTELESS (SPL) acts as a transcriptional repressor recruiting corepressor TPL/TPRs to TCP transcription factors during ovule development. SPL was found to be an essential factor for sporogenesis and the megasporocyte specification during ovule development 15 years ago. However, the molecular mechanisms of SPL in control of ovule development have not been discovered. We demonstrate that SPL functions as an adaptor-like transcriptional repressor. We identified that SPL recruited TPL/TPR co-repressors to inhibit TCP transcription factors. Our results define the action mechanism for SPL, which along with TPL/TPRs serves as a transcriptional repressor of CIN-like TCP transcription factors during ovule development.
We uncovered that the WRKY transcription factor WRKY71/EXB1 controls shoot branching by transcriptionally regulating RAX genes in Arabidopsis. The formation of branch meristems is regulated by several key transcription factors including REGULATOR OF AXILLARY MERISTEMS 1 (RAX1), RAX2, and RAX3. However, the regulatory network of shoot branching is still largely unknown. We identified that EXCESSIVE BRANCHES 1 (EXB1) affects both axillary meristem (AM) initiation and bud activities. Overexpression of EXB1 in the gain-of-function mutant exb1-D leads to severely bushy and dwarf phenotypes, which are resulted from both excessive AM initiation and elevated bud activities. EXB1 encodes a WRKY transcription factor WRKY71 with demonstrated transactivation activities. Disruption of EXB1 by chimeric repressor silencing technology leads to fewer branches, indicating that EXB1 plays important roles in control of shoot branching. We demonstrate that EXB1 controls AM initiation by positively regulating the transcription of RAX1, RAX2, and RAX3. Disruption of the RAX genes partially rescues the branching phenotype caused by EXB1 overexpression. We further show that EXB1 also regulates auxin homeostasis in control of shoot branching.
Fang YX, Guo DS, Wang Y, Wang N, Fang XW, Zhang YH, Li X, Chen LT, Yu DQ, Zhang BL, Qin GJ. (2024) Rice transcriptional repressor OsTIE1 controls anther dehiscence and male sterility by regulating JA biosynthesis. Plant Cell, 36: 1697-1717.
Wang YT, Wang N, Lan JQ, Pan YG, Jiang YD, Wu YQ, Chen XM, Feng XZ, Qin GJ. (2024) Arabidopsis transcription factor TCP4 controls the identity of the apical gynoecium. Plant Cell, 36: 2668-2688.
Yu H, Wang YT, Wang Y, Deng XW, Qin GJ. (2024) The Arabidopsis ring-type E3 ligase TEAR4 Controls seed germination by targeting RGA for degradation. Adv. Sci., 4: e2400116.
Lan JQ, Wang N, Wang YT, Jiang YD, Yu H, Cao XF, Qin GJ. (2023) Arabidopsis TCP4 transcription factor inhibits high temperature-induced homeotic conversion of ovules. Nat. Commun., 14: 5673.
HeQ, Yuan RR, Zhang TT, An FY, Wang N, Lan JQ, Wang XX, Zhang ZL, Pan YG, Wang XZ, Zhang JZ, Guo DS, Qin GJ. (2022) Arabidopsis TIE1 and TIE2 transcriptional repressors dampen cytokinin response during root development. Sci. Adv., 8: eabn5057.
Zheng XH, Lan JQ, Yu H, Zhang JZ, Zhang Y, Qin YM, Su XD, Qin GJ. (2022) Arabidopsis transcription factor TCP4 represses chlorophyll biosynthesis to prevent petal greening. Plant Commun., 3: 100309.
Qin WQ, Wang N, Yin Q, Li HL, Wu AM and Qin GJ. (2022) Activation tagging identifies WRKY14 as a repressor of plant thermomorphogenesis in Arabidopsis. Mol. Plant., 15: 1725-1743.
Lan JQ, Zhang JZ, Yuan RR, Yu H, An FY, Sun LH, Chen HD, Zhou Y, Qian WQ, He H, Qin GJ. (2021) TCP transcription factors suppress cotyledon trichomes by impeding a cell differentiation-regulating complex. Plant Physiol., 186: 434-451.
Lan JQ, Qin GJ. (2020) The regulation of cin-like tcp transcription factors. Int. J. Mol. Sci., 21: 4498.
Fengying An, Guiying Sun, Yutao Wang, Weiqi Qin, Qi Yin, Yi Wang, Ning Wang, Yige Pan, Zeliang Zhang, Xinxue Wang, Shiyi Li, Yidan Jiang, Yu Cao, Ping Chen, Yiyi Li
