摘要：

STAT蛋白是一类在信号传导和基因转录激活方面具有重要作用的转录因子。在植物中STAT基因的表达与高温等非生物胁迫相关。为了研究玉米STAT基因是否参与响应高温胁迫,以耐高温胁迫的Zheng 58和对高温敏感的PH6WC玉米自交系为材料,选取高温和常温2个条件下生长的植株根、茎、叶、花粉和花丝5个部位的组织进行转录组测序。基于测序数据,对玉米STAT基因结构、编码蛋白的理化性质及其在不同玉米材料、不同温度条件下的组织表达模式进行分析。结果表明,在玉米中鉴定到2个STAT基因Zm-STAT1和Zm-STAT2,其中,Zm-STAT1编码的蛋白是疏水蛋白,而Zm-STAT2编码的蛋白是亲水蛋白,它们都具有多个功能位点和磷酸化修饰位点。进一步表达分析发现,以常温为对照,在高温条件下,Zm-STAT1基因在PH6WC的根中、Zm-STAT1基因在Zheng 58的花粉和花丝中表现为上调表达,而Zm-STAT1基因在PH6WC的茎和叶中、Zm-STAT2基因在PH6WC的叶中则表现为下调表达。在2个温度条件下,Zm-STAT2在5个组织中的表达量均显著高于Zm-STAT1,且ZmSTAT2在耐高温胁迫材料Zheng 58的根、茎、花粉和花丝中均受高温诱导,暗示Zm-STAT2基因参与了玉米高温胁迫响应。

关键词: 玉米, 高温胁迫, STAT转录因子, 基因结构, 表达模式

Abstract:

STAT proteins are a class of transcription factors that play crucial roles in signal transduction and gene transcriptional activation.In plants,the expression of STAT genes are associated with abiotic stresses such as high temperature.To investigate whether maize STAT genes are involved in the response to high-temperature stress,two maize inbred lines,Zheng 58(tolerant to high-temperature stress)and PH6WC(sensitive to high temperature),were selected as materials.The plant tissues from five parts(root,stem,leaf,pollen,and filament)of plants grown under high-temperature and normal-temperature conditions were used for transcriptome sequencing.Based on the sequencing data,the structure of STAT genes,the physicochemical properties of the proteins encoded by STAT genes,and tissue-specific expression patterns of STAT genes under different temperatures and materials were analyzed.The results showed that two STAT genes were identified in maize,named Zm-STAT1 and Zm-STAT2.The protein encoded by Zm-STAT1 was hydrophobic,while that encoded by Zm-STAT2 was hydrophilic,both containing multiple functional and phosphorylation modification sites.Further expression analysis revealed that, with room temperature as the control, under high-temperature conditions, Zm-STAT1 gene was upregulated in the root of PH6WC and in the pollen and filament of Zheng 58, whereas Zm-STAT1 gene in the stem and leaf of PH6WC and Zm-STAT2 gene in the leaf of PH6WC were down-regulated expression. Under both temperature conditions,the expression level of Zm-STAT2 was significantly higher than that of Zm-STAT1 across all five tissues.Notably,Zm-STAT2 was induced by high temperature in root,stem,pollen,and filament in the heat-tolerant Zheng 58,suggesting that Zm-STAT2 gene was involved in high-temperature stress response.

Key words: Maize, High-temperature stress, STAT transcription factor, Gene structure, Expression pattern

中图分类号: 

• S513.03

• Q78基因工程(遗传工程)