报告题目：Molecular understanding of epigenetic ‘memory of winter cold’ and flowering-time regulation in Arabidopsis
报告人：何跃辉 北京大学高等农业科学学院
主持人：许 玲 教授
报告时间：2020年11月20日上午9：00（周五上午）
报告地点：生命科学学院534报告厅
报告人简介：
Prof. He received his Ph.D. degree from the University of Kentucky in 2001, and subsequently conducted his postdoctoral research at the University of Wisconsin-Madison. In 2005, he was appointed as Assistant Professor and started his own research program of plant environmental epigenetics in the Department of Biological Sciences at National University of Singapore (NUS). In 2006, he was jointly appointed as Principal Investigator in the Temasek Life Sciences Laboratory (TLL). In January 2012, he was promoted to Associate Professor with tenure by NUS, followed by his promotion to Senior Principal Investigator at TLL. In 2014, he relocated his laboratory from Singapore to the Shanghai Center for Plant Stress Biology (PSC), Chinese Academy of Sciences. Since October 2020, he has been a full professor in the School of Advanced Agricultural Sciences, Peking University and a senior principal investigator at Peking University-Institute of Advanced Agricultural Sciences.
The laboratory of Plant Environmental Epigenetics led by Prof. He has been studying the molecular epigenetic mechanisms underlying flowering-time regulation by seasonal environmental signals including winter cold and photoperiod, through the vernalization pathway and the photoperiod pathway, and has uncovered how various chromatin modifiers function together with transcriptional factors to mediate photoperiodic or cold regulation of flowering time using the model plant Arabidopsis. As a leading or correspondence author, Prof. He has published over ten research articles in top-tier journals including Nature, Science, Nature Genetics, Nature Biotechnology, and Nature Plants.
报告内容：
In many plants grown at a high latitude, flowering is enabled by experiencing prolonged cold exposure in winter (winter cold). Through a process termed as vernalization, winter cold often triggers the repression of a potent floral repressor to enable plants to flower in spring when temperature rises. In over-wintering Arabidopsis accessions, vernalization induces the silencing of the potent floral repressor FLOWERING LOCUS C (FLC), encoding a MADS-box transcription factor that inhibits flowering. This enables Arabidopsis plants to flower in next spring. Winter cold causes repressive histone modifications such as histone 3 lysine-27 trimethylation (H3K27me3) on FLC chromatin for transcriptional repression. When temperature rises in spring, the silenced FLC state is epigenetically maintained in subsequent growth and development (i.e. ‘memory of winter cold’), enabling plants to flower, but this state is transmitted or inherited to the zygote and early embryos, but is subsequently reset by the end of embryo development to ensure that each generation must experience winter cold prior to flowering. Recently, we have found that several cis-regulatory DNA elements and a few trans-acting proteins including transcription factors and chromatin modifiers, function in concert to dynamically mediate FLC regulation in response to seasonal signal-winter cold. These findings will be presented in the lectures.