基于转录组和代谢组的马铃薯抗寒相关途径分析及抗寒机理解析

Current potato varieties are sensitive to frost during plant growth which is a great threat to potato production. Two kinds of cold resistance have been clarified, the non-acclimate resistance (NAR) and low temperature-induced acclimate resistance (AR). However, little is known about their mechanisms, a causal for ineffective improvement of the cold resistance in potato. In this proposed project, seven wild species and one spp. tuberosum cultivar with different level of NAR and AR will be used for systemic analysis of the molecular and metabolic mechanisms underlying potato NAR and AR by an integrated strategy of transcriptomics and metabolomics. The molecular mechanisms of NAR and AR and their relationships could be revealed by clarifying the regulatory ways and the key regulation factors. Meanwhile, comparison between diverse genotypes may offer some insight into the mechanism of potato cold resistance.

现有栽培的马铃薯品种不抗霜冻，生长期间的寒害对马铃薯生产的造成严重威胁。马铃薯对寒害的抗性包括本身所具备抗寒性和由低温诱导产生的驯化抗性，然而相关机理研究十分缺乏，导致抗寒性状改良成效甚微。本项目拟通过具有不同抗寒水平和抗寒驯化能力的7份马铃薯野生种和1份栽培种，利用转录组学和代谢组学结合的途径，系统研究马铃薯对寒害和低温驯化响应的分子和代谢基础，解析非驯化抗寒和驯化抗寒的调控途径和关键调控因子，以揭示两种抗寒能力形成的分子机制及其相互关系。同时，通过不同遗传背景材料的比较，明确不同野生种抗寒机制上的差异，较全面地解析马铃薯抗寒机理。

针对霜冻严重威胁马铃薯产业发展，正向遗传学无法有效解析马铃薯抗寒分子机理，申请人在本项目的资助下，通过转录组和代谢组结合的途径，解析了马铃薯冷驯化能力和非驯化抗寒能力的分子机理。结果显示，钙信号途径、MAPK cascades、IP3、腐胺等信号途径参与形成马铃薯的冷驯化能力；不同马铃薯野生种通过调用上述不同信号通路来实现抗寒能力的提高；本研究采用的马铃薯野生种均调用了钙信号途径，该途径可能在马铃薯冷驯化能力形成过程中发挥着核心作用；马铃薯组成型抗寒能力与CBF组成型表达有关。进一步展开腐胺途径的功能验证和机理解析时，结果显示腐胺途径虽不能提高组成型抗寒能力，但可提高马铃薯冷驯化抗寒能力。机理解析揭示腐胺在马铃薯中通过调控CBF，而不是以往模式作物中报道的ABA含量进而提高抗寒能力。本研究较好的解析了马铃薯的抗寒机理，同时挖掘出了大量关键候选调控基因，为全面解析马铃薯抗寒机理奠定了良好基础。