DNA甲基化介导调控小麦光温敏雄性不育性的机制研究

Photoperiod and thermo-sensitive genetic male sterility (PTGMS) is widespread ecological sterility type in plant, which has been widely used in rice and wheat heterosis systems, but its genetic regulation mechanism has not been announced. Studies have shown that environmental change caused by DNA methylation and other epigenetic modifications can be passed on to offspring at the meiosis stage. DNA methylation plays an important role in regulating gene expression in the process of plant growth and development. In this study, based on PTGMS lines BS366 of our team independent breeding, the anther tissue samples DNA and RNA of different meiosis periods were extracted in the different light and temperature conditions, and carried out methylation and transcriptome high-throughput sequencing. By using the bioinformatics softwares, the different methylated loci and different expression of related genes were analyzed, in order to clarify the relationship of key methylated sites, the expression of target genes and PTGMS, construct its epigenetic regulation network model to reveal PTGMS mechanism and provide the theory basis, and further to promote widespread application of our country original two-line hybrid wheat system and lay the important theoretical basis.

光温敏不育性是植物中广泛存在的生态型不育类型，在水稻、小麦杂种优势体系中已被广泛利用，但其遗传调控机理至今尚未揭晓。研究表明，环境改变引起的DNA甲基化等表观遗传修饰可通过减数分裂遗传给后代，对植物生长发育过程中基因表达调控具有重要作用。本研究以课题组选育的小麦光温敏雄性不育系BS366为对象，分别提取不同光、温环境下减数分裂不同时期花药组织样本的DNA及RNA，进行甲基化及转录组高通量测序，分析甲基化差异位点及相关基因的差异表达，揭示关键甲基化位点及其靶基因的表达与光温敏不育性的关系，构建小麦光温敏雄性不育表观遗传调控网络模型，为揭示小麦光温敏雄性不育机理提供理论依据，为促进我国原创性二系杂交小麦体系的应用奠定理论基础。

温光敏不育性是植物中广泛存在的生态型不育类型，在禾本科作物水稻、玉米和小麦杂种优势中已被广泛利用，但其遗传调控机理至今尚未揭晓。研究表明，环境改变引起的DNA甲基化表观遗传修饰可通过减数分裂遗传给后代，对于植物生长发育、开花结实过程中关键基因的表达具有重要调控作用。本研究以课题组选育的小麦光温敏雄性不育系BS366为对象，常规品种京411为对照，分别提取可育（北京顺义）及不育（河南邓州）环境下减数分裂不同时期花药组织的DNA及RNA进行甲基化及转录组高通量测序联合分析。通过对甲基化差异位点及相应的转录组差异表达基因GO功能注释分析发现，染色体组装的相关基因可能参与了光温敏不育表型调控，对这些候选基因的启动子区、编码区、3'端非编码区CG、CCGG甲基化分布发现，启动子区的甲基化程度显著高于其它区域，其表达水平和甲基化程度成显著负相关。对AGO1、NIP1、GDSL、Malate等10个候选基因进行特定区域亚硫酸盐测序验证，发现AGO1、H2A、Malate基因的甲基化水平与表达水平呈显著负相关。对这3个候选基因深入开展荧光定量及组织原位杂交验证，发现这3个基因在不育环境下花药组织中高表达，而在可育环境下花药组织表达量较低，几乎检测不到荧光信号，从而证明它们可能参与调控了不育环境下光温敏雄性不育系BS366的育性。上述研究结果初步揭示甲基化表观修饰对小麦光温敏雄性不育系BS366育性相关靶基因的表达调控关系，为阐明小麦光温敏雄性不育分子机理提供理论依据，为完善提升我国原创性二系杂交小麦应用体系奠定了科学研究基础。