摘要： 为了探明玉米重要自交系花粒期高温胁迫下转录组基因的表达差异，发掘玉米响应高温胁迫的关键基因和蛋白质，明确高温胁迫引起玉米减产的机理，从而利用分子生物学技术手段提高玉米耐高温胁迫性。首先，利用Ampha^TM Z30花粉活性分析仪检测高温胁迫和正常生长条件下玉米自交系昌7-2、郑58的花粉活性。然后收集花粉提取总RNA，利用Illumina Hiseq2000^TM高通量测序技术分别对昌7-2、郑58花粒期高温胁迫材料和正常生长条件下的对照材料进行全转录组测序，序列结果分析后获得差异显著表达基因。通过差异基因维恩图（VENN图）重叠区域分析、GO功能分类和富集统计、KEGG pathway通路分类和富集分析以及转录因子分析，获得玉米花粒期高温胁迫相关的重要差异表达基因和蛋白质。花粉活性检测结果显示，高温胁迫后和正常生长条件下，昌7-2花粉活性分别为24.37%，42.89%，郑58花粉活性分别为35.57%，64.83%。高温胁迫后在昌7-2花粉转录组中共检测到4 176个显著差异表达基因，郑58花粉转录组中共检测到5 487个显著差异表达基因。KEGG pathway通路分类和富集分析结果显示，高温胁迫后郑58的花粉转录组中有2 062个差异表达基因富集到399个相关通路上，昌7-2的花粉转录组中有1 943个差异表达基因富集到352个相关通路上。转录因子分析结果表明，共获得55个转录因子家族，其中，有45个转录因子包含10个以上差异表达基因。研究表明，通过对玉米自交系花粒期高温胁迫后花粉转录组测序获得了大量的差异显著表达基因信息，昌7-2、郑58对高温胁迫响应机制存在明显差异，热激蛋白（Hsps）、热激转录因子（Hsfs）、生长素（IAA）基因和磷脂酰基醇-4，5-二磷酸基因家族（PIP₂）在响应玉米花粒期高温胁迫过程中起着重要作用。

关键词: 玉米自交系, 花粒期, 高温胁迫, 转录组测序, 差异表达基因

Abstract: The objective of this study was to investigate the transcriptome differences after and before high temperature stress during maize anthesis stage, and to explore the key genes and proteins which are contributed to the high temperature resistant. The pollen activities of maize inbred lines Chang 7-2 and Zheng 58 were detected by Ampha^TM Z30 pollen activity analyzer (Amphays, Switzerland), firstly. RNA-sequencing, construction library and quality assessment were carried out for two periods before and after high temperature treatment using the Illumina Hiseq2000^TM sequencing platform, then the sequencing results were analyzed by bioinformatics. The differential expression genes (DEGs) were analyzed using edegR software. Key different expression genes and proteins with high temperature resistance were analyzed by VENN mapping, GO functional enrichment, KEGG pathway method and transcription factors analysis.The pollen activity of Chang 7-2 grown in normal condition was 42.89% and the pollen activity which was treated by high temperature during anthesis stage was 24.37%. The pollen activity of Zheng 58 which was grown in normal condition was 64.83% and the pollen activity treated by high temperature was 35.57%. The results showed that 4 176 significant DEGs were detected in Chang 7-2 inbred under normal growth condition and high temperature treatment. 5 487 significant DEGs were detected in Zheng 58 inbred under normal growth condition and high temperature treatment. KEGG pathway enrichment analysis showed that 2 062 differentially expressed genes in Zheng 58 were enriched in 399 related pathways. KEGG pathway enrichment analysis showed that 1 943 DEGs in Chang 7-2 were enriched in 352 related pathways. A total of 55 transcription factor families were obtained by the transcription factor analysis, of which 45 transcriptional factors contained more than 10 differentially expressed genes. In conclusion, Comparing the RNA-sequencing after and before high temperature treatment of Chang 7-2 and Zheng 58, many DEGs were obtained. The differences of response mechanisms between Chang 7-2 and Zheng 58 to anthesis high temperature stress were comparatively analyzed. The three gene families (Hsfs, IAA and PIP₂) and the Hsps proteins are playing significant roles in the regulation of high temperature stress in maize.

Key words: Maize inbred lines, Anthesis stage, High temperature stress, Illumina RNA-sequencing, Differentially expressed genes (DEGs)

中图分类号: 

• S513.03