题目：植物如何感受重力 

主讲：陈浩东 研究员（清华大学）

时间：11月13日（周一）11:00-12:00

会议地点：慧园4栋301会议室

报告摘要：Gravity controls directional growth of plants, and the classical starch-statolith hypothesis proposed more than a century ago postulates that amyloplast sedimentation in specialized cells initiates gravity sensing, but the molecular mechanism remains uncharacterized. The LAZY proteins are known as key regulators of gravitropism and lazy mutants show striking gravitropic defects. Here, we report that gravistimulation by reorientation triggers Mitogen-Activated Protein Kinase (MAPK) signaling-mediated phosphorylation of Arabidopsis LAZY proteins basally polarized in root columella cells. Phosphorylation of LAZY increases its interaction with several Translocons at the Outer envelope membrane of Chloroplasts (TOC) proteins on the surface of amyloplasts, facilitating enrichment of LAZY proteins on amyloplasts. Amyloplast sedimentation subsequently guides LAZY to relocate to the new lower side of the plasma membrane in columella cells, where LAZY induces asymmetrical auxin distribution and root differential growth. Together, this study provides a molecular interpretation for the starch-statolith hypothesis: the organelle movement-triggered molecular polarity formation.

个人简介：陈浩东，研究员，博士生导师，清华大学生命科学学院及清华-北大生命科学联合中心。2003年与2008年分别获得北京大学生命科学学院学士与博士学位，2010年至2020年任北京大学生命科学学院/现代农学院副研究员，2020年至今任清华大学生命科学学院研究员。长期研究物理环境因子重力和光对植物生长发育的调控，近期主要研究植物中的重力感受与信号传递的机制。近年来，揭示了植物通过“淀粉-平衡石”感受重力的分子机制，解析了微管马达蛋白调控植物向重力性方向的机制，阐明了生长素下游特定基因的不对称表达调控植物胚轴向重力性与向光性的机理，发现了光信号差异性调控植物茎和根向重力性的机制。相关研究成果以通讯作者发表在Cell、Nature Communications、Current Biology、PNAS、Cell Reports、Plant Cell、Molecular Plant等国际学术期刊上。获得国家自然科学基金委优秀青年科学基金、创新研究群体，国家重点研发计划等项目资助。