DOG1基因参与调控刺萼龙葵种子季节性休眠的分子机制

Buffalobur (Solanum rostratum Dunal) is a highly dangerous noxious and worst weed. It is an important invasive species for management by our government and now it is entering a rapid dispersal period characterized by broad occurrence, severe infestation and fast spreading. Regulation of the seed dormancy is the crucial strategy to control its further infestation and dispersal. Targeting on the main objectives of DOG1 (Delay of Germination 1), a dormancy-specific gene, for regulating seed dormancy of buffalobur and by using the theories and methods of seed ecology, physiology and molecular biology, mechanisms of DOG1 in regulating seasonal seed dormancy of buffalobur will be studied systematically. The research mainly deals with the cloning and functional analysis of DOG1 gene of buffalobur; the spatial and temporal expression of DOG1; correlation of DOG1 expression with the seed germination under seasonal dormancy process; the mode of DOG1 responses to environmental signals; the interaction of DOG1 with the genes related to GA and ABA biosynthesis pathway, and finally revealing the molecular mechanism of DOG1 in regulating seasonal seed dormancy in buffalobur. Our research not only could elucidate the DOG1 involved signaling pathway, but also could provide theoretical basis for making strategies for control of buffalobur, which will be helpful to safeguard the ecological safety and food safety of our country.

刺萼龙葵(Solanum rostratum)是一种高度危险的有毒有害杂草，是我国重点管理的外来入侵物种，种子休眠的调控是遏制其种群萌发定植和传播扩散的关键途径。本研究重点围绕休眠特异相关基因DOG1（Delay of Germination 1）对刺萼龙葵种子休眠的调控这个主题，应用种子生态学、生理学和分子生物学的理论和方法，系统研究DOG1基因对刺萼龙葵种子季节性休眠的调控机制。主要对刺萼龙葵DOG1基因进行克隆和功能鉴定，研究DOG1基因的表达特性和时空特征、季节性休眠过程中种子萌发水平与DOG1基因表达水平的相关性、DOG1基因对环境信号的响应模式及与ABA和GA信号通路相关基因的互作机理，从而揭示DOG1基因参与调控刺萼龙葵种子季节性休眠的分子机制。研究结果不仅可以明晰DOG1关联的种子休眠调控信号通路，而且可为刺萼龙葵防控策略的制订提供重要理论依据，保障我国生态安全和粮食安全。

刺萼龙葵（Solanum rostratum Dunal）是原产北美的茄科有毒有害杂草，被列为我国首批重点管理的外来入侵物种之一。种子是草害发生和传播扩散的关键载体，种子休眠萌发的合理调控对草害可持续绿色防控具有重要意义。针对刺萼龙葵种子具有组合休眠特性，难以有效根除这一关键防控难题，我们对延迟萌发基因DOG1参与调控刺萼龙葵种子休眠和萌发的分子机理进行了深入研究。通过项目研究，克隆获得了刺萼龙葵延迟萌发基因DOG1全长，明确了基因的序列特征及对种子热休眠的调控功能；筛选得到了刺萼龙葵基因表达分析的适宜内参基因，建立了基因表达检测的qPCR方法-双标准曲线法；应用该方法分析阐明了刺萼龙葵种子在不同贮存时间、不同萌发阶段、不同生育期及不同组织部位的DOG1基因的表达特性。采用转录组测序和qPCR检测解析了刺萼龙葵浸种萌发过程中DOG1基因与ABA和GA信号通路中相关基因的差异表达和互作机理，发现多个差异基因的表达动态显著受外源ABA和GA影响，与种子休眠萌发进程密切相关，由此成功构建了相关基因的信号传导途径。研究结果系统揭示了DOG1基因参与调控刺萼龙葵种子休眠萌发的分子机制，为以萌发调控方式防控刺萼龙葵策略的制定提供了重要依据。项目资助发表国内外核心期刊论文4篇，其中SCI论文3篇，投稿已录用论文2篇；培养研究生2名；参加国际国内会议9人次，作相关研究进展报告5人次。