Xiaojie Tian: The Plant Cell First Author

Xiaojie Tian, first author of “WRKY53 Integrates Classic Brassinosteroid Signaling and the Mitogen-Activated Protein Kinase Pathway to Regulate Rice Architecture and Seed Size”

Current Position: Research associate, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China

Education: Ph.D., Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China

Non-scientific Interests: riding, swimming, dancing

Brief bio:

In September 2012, I joined the Bu Qingyun’ lab in the Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, and started my Ph.D study. I generated a number of transgenic lines in which diverse transcription factors were overexpressed. Among them, OsWRKY53 overexpression lines with the significantly increased leaf angle and grain size was chosen for further study. we found that OsWRKY53 is the phosphorylated substrate of OsMAPK6, and positively regulates BR signaling and rice architecture, and the relative result was published in Plant physiology in 2017. After I finished my PhD study, I, as a research associate, continued to investigate the role and mechanism of OsWRKY53 in the BR signal transduction pathway. we found that OsWRKY53  interacts with and is phosphorylated by OsGSK2, a major negative regulator of BR signaling. OsGSK2 destabilizes the protein stability of OsWRKY53, and genetic evidence supports that OsWRKY53 functions downstream of OsGSK2. simultaneously, we found OsWRKY53 also interacts with OsBZR1, and they coordinately regulate BR signaling in a parallel relationship. consistent with previous results, we also provided more genetic data supporting that OsWRKY53 is a downstream target gene of MAPK signalling as well. Therefore, these founding suggest that WRKY53 might function as a common target of GSK2 and MAPK6 to mediate the cross-talk between BR and MAPK signalling pathway, which not only reveal the mechanism of WRKY53 in regulating the seed size and leaf angle, but also strengthen our understanding of the BR and MAPK signalling pathway.







2012年9月进入中国科学院东北地理与农业生态研究所卜庆云研究员课题组开启硕博连读生涯。通过农杆菌介导的遗传转化方法侵染水稻愈伤,获得多个水稻转录因子的过表达转基因材料,首次发现OsWRKY53过表达转基因水稻株型独特,表现为叶倾角和粒型显著增大;深入研究发现,OsWRKY53是OsMAPK6的磷酸化底物,正向调控BR信号和水稻株型。并将这部分工作,于2017年发表在植物学期刊Plant physiology上。同年获得博士学位,并继续留所工作,探究OsWRKY53在BR信号转导通路中的作用位点和作用机制。结果发现,OsWRKY53能够与BR信号负调控因子OsGSK2相结合,OsGSK2通过磷酸化OsWRKY53降低其蛋白稳定性;进而通过遗传学证据进一步证明OsWRKY53作用于OsGSK2的下游发挥生物功能。同时,OsWRKY53也能够结合BR信号正调控因子OsBZR1,二者协同抑制BR生物合成基因OsD2的表达;并进一步通过遗传学证据充分证实,OsWRKY53与OsBZR1以一种平行的相互作用关系,协同调控BR信号反应。另外,我们还进一步通过遗传学证据,证明OsWRKY53也是MAPK信号下游靶基因,参与调控水稻株型和粒型。首次解析了BR信号与MAPK信号之间的交叉对话,不仅丰富了BR信号调控网络,也扩展了MAPK信号调控模式。