Abstract:

Transcription factors play important roles in plant development and response to stress in external environment. MYB family is a kind of plant transcription factor family with larger numbers and multiple functional diverse. This study took salt tolerant variety 177 and its recurrent parent IR64 as material, and treated them with salt and salt+ABA, then quantitative Real-time PCR was used to compare and analyze the expression profile of 43 MYB transcription factors. The results showed that 42% and 58% MYB transcription factors in IR64 and 177 were down-regulated in leave tissues under salt stress, while after exogenous ABA application the expression level of 61% (IR64) and 68% (177) those genes were significantly enhanced. This result indicated that exogenous ABA could change the expression patterns of MYB transcription factors under salt treatment, and then affected the rice salt tolerance. At the same time, this study identified 12 MYB transcription factors expressed differentially between 177 and IR64. The expression patterns of those genes might closely related to the different salt tolerance of these 2 varieties. This study provided theoretical referrances for further analyzing the mechanism of MYB genes in rice responce to salt tolerance, and the role of ABA in enhancing rice salt tolerance.

Key words: rice, salt, ABA, expression profile, MYB

摘要：

转录因子在植物生长发育和响应外界环境胁迫过程中起重要作用。MYB类转录因子是植物中数量较多、功能多样化的一类转录因子。以耐盐聚合系177，以及该聚合系的轮回亲本IR64为材料，在苗期进行盐和盐+ABA处理，采用荧光定量PCR方法，比较分析了43个MYB家族基因在盐胁迫和盐+ABA处理下的表达谱。结果表明，在盐胁迫条件下，IR64和177中分别有42%和58%的MYB基因在叶片组织中下调表达，而外施ABA后，61%（IR64）和68%（177）的下调基因表达量显著增强。该结果说明盐处理条件下通过外施ABA能够引起MYB基因的表达变化，进而影响水稻的耐盐性。同时鉴定了12个在IR64和177间显著差异表达的MYB基因，该类基因的表达模式可能同两个品种具有不同的耐盐性紧密相关。该结果为进一步分析水稻MYB基因在响应盐胁迫过程中的作用机制以及ABA在增强水稻耐盐性方面提供了理论参考。

关键词: 水稻；盐；ABA；表达谱；MYB