题目：Regulation of Pollen–Stigma Interactions by Peptides-Receptor Kinases

主讲：李超 研究员（华东师范大学）

时间：9月27日（周五）10:00-11:00

会议地点：慧园4栋301

报告摘要：In angiosperms, successful sexual reproduction relies on complicated communications between male and female organs. However, the mechanisms underlying the pollen-pistil interaction is far from thoroughly understood. In the study of the pollen-stigma interaction, we established a lock-and-key mechanism that before pollination FERONIA receptor kinase and its homolog ANJEA (FER–ANJ) perceives the RAPID ALKALINIZATION FACTOR peptides RALF23/33, inducing the generation of reactive oxygen species (ROS) in stigma papillary cells via a ROP2–RBOHD pathway; during pollination, the POLLEN COAT PROTEIN B-class peptides (PCP-Bs) compete with RALF23/33 for binding to FER–ANJ, leading to a reduction in stigmatic ROS and subsequently facilitating pollen hydration. In addition, we obtained some interesting findings in unraveling the signaling pathways governing basal stigmatic responses regulated by pollen peptides and pistil receptor kinases. These studies underscore the precise regulation of plant development by receptor kinases that perceive and switch between different types of peptide ligands. In the study of pollen tube growth, we found that glycosylphosphatidylinositol-anchored proteins LLG2/3 act as chaperones to facilitate the trafficking of AUX/BUPS receptor kinases from the endoplasmic reticulum to the plasma membrane of the pollen tube tip region; wherein LLG2/3 serve as coreceptors of ANX/BUPS receptor kinases to perceive the RALF4/19 peptides and activate a RAC/ROPs–NADPH oxidases–ROS pathway, which assures the cell wall integrity during the fast growth of pollen tubes. Further exploring the downstream of CrRLK1Ls–ROS pathway, we disclosed that auxin activates the FER–ROS pathway, triggering ROS production in root hairs and inducing the oxidative modifications of TIR1/AFB2, which facilitate their nuclear import and transcriptional auxin responses. These studies deepen our understanding of the peptide-receptor kinase-regulated intercellular communication mechanisms in the regulation of plant sexual reproduction, which provide important theoretical foundations for hybrid breeding.

个人简介：李超博士，华东师范大学生命科学学院研究员、植物学科主任。获国家自然科学基金杰青和重点项目、上海市青年英才计划拔尖项目、中国植物生理与植物分子生物学学会 “卫志明青年创新奖”、上海生物化学与分子生物学学会“青年新锐奖”。2002年于中国农业大学获学士学位并进入中科院遗传与发育生物学研究所开展硕博连读，2005-2008年在北京生命科学研究所联合培养，2008年获博士学位后到美国马萨诸塞大学开展博士后研究。2016年起在华东师范大学建立独立课题组，围绕类受体激酶调控植物发育的分子机理开展工作，在花粉-柱头识别、花粉管生长和根毛发育等方面取得重要进展,主要成果发表在Science、Molecular Plant、eLife、Plant Physiology等国际知名期刊。