Run Han, co-first author of “SALT OVERLY SENSITIVE2 stabilizes phytochrome-interacting factors PIF4 and PIF5 to promote Arabidopsis shade avoidance”
“Phytochromes enhance SOS2-mediated PIF1 and PIF3 phosphorylation and degradation to promote Arabidopsis salt tolerance”
Current Position: Postdoc, China Agricultural University
Education: B.S. (2015) from Northwest Agriculture & Forestry University; Ph.D. (2021) from China Agricultural University
Non-scientific Interests: Reading and Travelling
Brief bio: After obtaining the bachelor’s degree from Northwest A&F University in 2015, I had the privilege of joining Professor Jigang Li’s Lab at China Agricultural University as a Ph.D. student. Professor Li’s Lab is interested in investigating how plants coordinately respond to combinations of abiotic stresses, and my research has been focused on studying the molecular mechanisms underlying the crosstalk between shade avoidance and salt stress. Our study revealed that the salt tolerance regulator SALT OVERLY SENSITIVE2 (SOS2) promotes shade avoidance in Arabidopsis by stabilizing the phytochrome-interacting factors PIF4 and PIF5. Further analyses indicated that SOS2 directly phosphorylates PIF4 and PIF5 at a serine residue close to their conserved motif for binding to active phyB, thus decreasing their interactions with phyB and promoting their protein stability. In addition, in the companion study by Ma et al. (2023), on which I was the co-first author, we found that SOS2-mediated phosphorylation of PIF1 and PIF3 promotes their degradation, and thus relieves their repressive effect on plant salt tolerance. Interestingly, both studies uncover that the photoreceptors phyA and phyB directly interact with SOS2 and induce its kinase activity in the light. Our study demonstrates that SOS2 serves as a key integrator of external light environment and internal salt stress signaling pathways, providing insight into how plants coordinately respond to multiple environmental stresses. I am very honored to share my work with the peers in The Plant Cell.
论文：“SALT OVERLY SENSITIVE2 stabilizes phytochrome-interacting factors PIF4 and PIF5 to promote Arabidopsis shade avoidance” and “Phytochromes enhance SOS2-mediated PIF1 and PIF3 phosphorylation and degradation to promote Arabidopsis salt tolerance”
我于2015年从西北农林科技大学本科毕业后，非常幸运地进入中国农业大学生物学院李继刚教授实验室攻读博士学位。李老师实验室对植物在复杂逆境下的协同响应机制很感兴趣，而我的博士课题是研究SOS2如何帮助植物同时响应遮荫和盐双重逆境胁迫。SOS2是植物响应盐胁迫的关键激酶，我们的研究发现SOS2通过促进PIF4/PIF5蛋白积累，正调控植物的避荫反应，而且该功能在植物处于遮荫和盐胁迫双重逆境下更为显著。进一步研究发现，SOS2通过磷酸化PIF4/PIF5蛋白APB基序附近的一个保守Ser位点，阻碍PIF4/PIF5与活性形式phyB的相互作用，从而促进PIF4/PIF5蛋白的稳定性。此外，我作为共同第一作者发表在The Plant Cell的背靠背论文 (Ma et al., 2023) 揭示了SOS2介导PIF1/PIF3蛋白磷酸化并促进它们降解，从而减缓PIF1/PIF3对植物耐盐的抑制作用。有趣的是，两篇论文同时发现光受体phyA/phyB与SOS2直接相互作用，在光下促进SOS2的激酶活性。我们的研究表明SOS2是植物整合环境光信号和内源盐胁迫响应信号的关键节点，为深入理解植物对复杂逆境的响应机制提供了新的见解。我非常荣幸能够在The Plant Cell杂志与各位同行分享我的研究成果。