Jian Hu, first author of “AUXIN RESPONSE FACTOR 7 integrates gibberellin and auxin signaling via interactions between DELLA and AUX/IAA proteins to regulate cambial activity in poplar”
Current Position: PhD candidate at the School of Life Sciences, Southwest University, Chongqing, China.
Education: B. Sc. in the School of Bioinformatics, Chongqing University of Posts and Telecommunications, Chongqing, China.
Non-scientific Interests: Poems, Comic dialog, Reading.
Brief bio: I received my bachelor’s degree from Chongqing University of Posts and Telecommunications in 2015. Then I started a project of map-based cloning of key genes from silkworm mutants in Chun Liu’s group at State Key Laboratory of Silkworm Genome Biology, Southwest University. In 2017, I joined Prof. Keming Luo’s laboratory at the School of Life Sciences of Southwest University for my PhD study. We focus on the molecular dissection of secondary development of woody plants in their stems. Under the supervision of Prof. Keming Luo and Prof. Changzheng Xu, I have struggled to demonstrate the combined regulation of cambial activity by gibberellin and auxin during wood formation. In this study, we showed that the DELLA protein REPRESSOR of ga1-3 Like 1 (RGL1), AUXIN RESPONSE FACTOR 7 (ARF7) and Aux/INDOLE-3-ACETIC ACID 9 (IAA9) form a ternary complex that mediates the crosstalk between the auxin and GA signaling pathways in poplar stems during cambial development. ARF7 directly binds to the promoter region of WOX4 encoding a key regulator of cambial stem cells to modulate its expression, thus integrating auxin and GA signaling to regulate cambial activity. Furthermore, the direct activation of PIN-FORMED 1 (PIN1) expression by ARF7 in the RGL1-ARF7-IAA9 module increased the GA-dependent cambial activity via polar auxin transport. Collectively, these findings reveal that the crosstalk between auxin and GA signaling mediated by the RGL1-ARF7-IAA9 module is crucial for the precise regulation of cambial development in poplar.
个人简历：2015年，我在重庆邮电大学生命科学学院取得学士学位，并进入家蚕基因组国家重点实验刘春老师课题组有过短暂的家蚕突变体研究。2017年，有幸进入西南大学生命科学学院罗克明老师课题组攻读博士学位。在罗克明教授和许长征教授的指导下，我们致力于阐释赤霉素和生长素协同调控形成层活性的分子机制。在这项研究中，我们发现DELLA 蛋白 ga1-3 Like 1 (RGL1)、AUXIN RESPONSE FACTOR 7 (ARF7) 和 Aux/INDOLE-3-ACETIC ACID 9 (IAA9)会形成三元复合物，介导杨树形成层发育过程中生长素和GA信号通路之间的互作。ARF7直接与形成层干细胞调节因子WOX4的启动子区域结合以促进其表达，从而整合生长素和GA信号以调节形成层活性。此外，ARF7在RGL1-ARF7-IAA9模块中直接激活PIN-FORMED 1 (PIN1)表达通过极性生长素转运从而增加形成层活性。这些研究结果表明，由RGL1-ARF7-IAA9模块介导的Auxin和GA信号通路的互作对于精确调控杨树形成层发育至关重要。