玉米穗发芽突变体vp⁃like8的转录组分析

Transcriptome analysis of maize viviparous mutant vp⁃like8

[目的]玉米穗发芽严重影响作物产量与品质,本研究通过分析玉米穗发芽突变体(viviparous)vp⁃like8与野生型在转录水平上的差异,探索玉米穗发芽相关基因调控网络,深入解析玉米穗发芽发生的分子机制。[方法]对本实验室发现的玉米穗发芽突变体vp⁃like8的杂合体分别与自交系Mo17和Zheng58杂交,然后再自交,随机选取具有穗发芽表型的F2果穗,发芽籽粒和正常籽粒各取40粒,剥除种皮,分别混池Mo17背景的突变体(Mo17_mut)和野生型(Mo17_wt),Zheng58背景的突变体(Zheng58_mut)和野生型(Zheng58_wt)等4份试验样品,利用转录组测序技术(RNA⁃Seq),借助生物信息学手段,对野生型和突变体进行比较转录组分析。[结果]在vp⁃like8突变体中,共筛选到2750个差异表达基因,其中1812个基因在突变体中上调表达,938个下调表达。GO(Gene ontology)功能富集分析和KEGG代谢通路富集分析发现,差异基因主要富集在代谢途径(Metabolic pathways)、光合作用(Photosynthesis)、植物激素信号转导(Plant hormone signal transduction)等生物途径,由此推测这些途径与玉米穗发芽是紧密相关的。[结论]本研究可为今后探究玉米穗发芽的分子机制和基因调控网络提供重要的数据支持。

[Objective]Vivipary severely impacts crop yield and quality.The present study was designed to determine the gene regulatory network and molecular mechanism of maize vivipary by analyzing the differences between maize viviparous mutant vplike8 and wide types at transcription levels.[Methods]The heterozygote of maize viviparous mutant vplike8 which was originally identified in our laboratory was crossed with inbred line Zheng58 or Mo17,and then selfed to produce F2.The F2 ears with viviparous phenotype were randomly selected along with 40 germinated seeds and regular seeds which were decorticated for RNA extraction.Then RNA-Seq were performed and the differences of transcription levels between wild and mutant types were analyzed using bioinformatics of the four bulked segregant samples including Mo17_mut,Mo17_wt,Zheng58_mut,and Zheng58_wt.[Results]A total of 2750 DEGs in vplike8 mutant and wild types were identified.Compared with wild type,there were 1812 up-regulated and 938 down-regulated genes in vplike8 mutant.Gene ontology(GO)and KEGG analysis showed that the DEGs played roles mainly in metabolic pathways,photosynthesis,plant hormone signal transduction which indicated that these processes were closely related to maize preharvest sprouting.[Conclusion]The results will provide important information on the molecular mechanism and gene regulatory networks of vivipary in maize.