作　　者： (王姗姗）; (赵影影）; (李超杰）; (谢小东）; (武明珠）; (李锋）; (杨军）; (王中）;

机构地区： 中国烟草总公司郑州烟草研究院,郑州高新技术产业开发区枫杨街2号450001

出　　处： 《烟草科技》 2017年第8期1-9,共9页

摘　　要： R2R3-MYB转录因子是植物中最大的转录因子家族之一,在植物生长发育和代谢活动中发挥着重要的调节作用。为明确MYB12转录因子在烟草中的生物学功能和调控机制,同源克隆了普通烟草MYB12基因(NtMYB12a和NtMYB12b),利用实时荧光定量PCR表征基因表达模式,结合生物信息学分析对基因功能和调控机制进行了初步预测。结果表明,NtMYB12a和NtMYB12b核苷酸序列一致性为92.91%,氨基酸序列一致性为87.91%。烟草MYB12基因结构高度保守,均由4个外显子和3个内含子组成。进化分析表明,普通烟草中NtMYB12a系由绒毛状烟草MYB12基因进化而来,而NtMYB12b则来源于林烟草。NtMYB12基因表达具有时空特异性,烟草在打顶以及盐、干旱、黑暗和磷饥饿等胁迫处理后,NtMYB12a和NtMYB12b基因表达差异明显,NtMYB12a基因表达水平在打顶处理下呈现上调趋势,在盐、黑暗和磷饥饿胁迫处理下显著下调,而在干旱胁迫下无明显变化;各种胁迫处理均可诱导NtMYB12b基因表达水平的提高,预示着NtMYB12基因在烟草响应各种非生物胁迫中发挥着重要的调控作用。 R2R3-MYB family is one of the largest transcription factor families in plants, and plays an important regulatory role in plant development and metabolism. To identify the biological functions and regulation mechanism of MYB12 transcription factors in tobacco, two MYB12 genes （NtMYB12a and NtMYB12b） were cloned from Nicotiana tabacum with homologous cloning strategy, gene expression patterns were analyzed by real-time quantitative PCR （qPCR）, and their functions and regulation mechanisms were predicted by bioinformatic analysis. The results showed that the nucleotide sequence and deduced amino acid sequence identities between NtMYB12a and NtMYBI2b were 92.91% and 87.91%, respectively. Highly conserved tobacco MYB12 genes included 4 exons and 3 introns. Phylogenetic analysis showed that NtMYB12a was evolved from Nicotiana tomentosiformis, while NtMYB12b from Nicotiana sylvestris. The expression patterns of NtMYB12a and NtMYB12b showed spatial and temporal specificity. Under topping, salinity stress, drought, darkness and phosphate starvation treatments, the expression levels of NtMYB12a and NtMYB12b were significantly different. The expression level of NtMYB12a in tobacco leaves presented an increase tendency after topping. Salinity stress, darkness and phosphate starvation significantly down-regulated the expression level of NtMYB12a, in comparison with no effect of drought. The expression levels of NtMYB12b were up-regulated under all treatments. The results indicated that NtMYB12 might play an important regulatory role in responding to abiotic stress.

关 键 词： 烟草 转录因子 表达模式 非生物胁迫 基因克隆