光质信号转录因子HY5介导光敏色素调控番茄低温抗性的机制研究

The chilling tolerance of temperate crops was heavily influenced by light quality in greenhouse during winter-spring season. We have found that far-red light-induced activation of phytochrome A could increase ABA accumulation and CBF transcript level, leading to an activation of a cold response in tomato plants. Based on current progress, we will use a series of tomato mutants, transgenic lines and RNAi plants involved in light receptor and signaling to study the changes of gene expression of transcription factor HY5 for light quality signaling and its repressor COP1 in response to temperature and light quality (the ratio of red to far-red light) and dissect the role of HY5 and COP1 in light quality-mediated chilling tolerance. We will identify ABA related genes potentially involved in quality-mediated chilling tolerance and then study their crosstalk with HY5 through EMSA and CHIP tests. Meanwhile, through transcriptomic analysis and VIGS technique, we will dissect the critical components involved in HY5-mediated chilling tolerance. The study will deepen the understanding of the molecular mechanisms of HY5 in phytochrome-mediated chilling tolerance in tomato. The research of the project will found theoretic bases for establishing a novel technology to regulate the vegetable tolerance to low temperature based on interplay of light and temperature signaling, and therefore is of fundamental significance for horticultural science and industry.

设施冬春生产中喜温作物的低温抗性受生长环境光质的影响。本项目在发现远红光FR可以通过光敏色素phyA促进ABA合成和CBF表达进而提高番茄耐冷性的基础上，以番茄不同红光R和FR光受体及光信号相关突变体、基因沉默或过表达植株为材料，研究低温下光质信号转录因子HY5及其抑制子COP1对不同比例R/FR光环境的响应变化；明确不同光质环境下HY5和COP1对番茄低温抗性的调控作用，并筛选参与低温抗性调控的ABA合成、代谢和信号途径相关基因；利用凝胶电泳迁移（EMSA）和染色质免疫共沉淀（CHIP）等技术研究HY5与筛选获得的ABA途径相关基因之间互作机制；利用转录组测序和高通量VIGS技术，筛选、鉴定HY5及COP1调控抗逆信号途径中的重要基因。研究可望阐明HY5介导光敏色素调控番茄低温抗性的分子机制，为建立一条基于光、温信号互作提高喜温蔬菜低温抗性的新途径奠定基础。

光质作为影响植物生长和发育的一个重要因素，在设施冬春生产中可影响喜温作物的低温抗性。本项目在发现远红光FR可以通过光敏色素phyA促进ABA合成和CBF表达进而提高番茄耐冷性的基础上，全面深入进行了光质信号转录因子HY5介导光敏色素调控番茄低温抗性机制的研究，明确了光敏色素A与光敏色素B在调控番茄低温抗性中的拮抗作用，并筛选出了参与低温抗性调控的脱落酸ABA合成基因SlNCED6、信号通路基因SlABI5，以及赤霉素GA的代谢相关基因SlGAI4，而转录因子HY5以及PIF4便是连接光质信号与激素信号的关键节点因子。本项目的研究内容在Plant Physiology 、Plant Cell and Environment 、Plant Biotechnology Journal、J.Exp.Bot等著名期刊上发表相关SCI论文10余篇，获授权相关国家发明2件，为建立一条基于光、温信号互作提高喜温蔬菜低温抗性的新途径奠定基础。