小麦转录因子TaMyb2s的克隆及表达  

Cloning and Expression of Transcription Factor TaMyb2s in Wheat

作　　者：贾东升[1,2] 毛新国[3] 景蕊莲[3] 张晓科[1] 昌小平[3] 

机构地区：[1]西北农林科技大学农学院 [2]中国农业科学院作物科学研究所/农作物基因资源与遗传改良国家重大科学工程/农业部作物种质资源与生物技术重点开放实验室,北京100081 [3]中国农业科学院作物科学研究所/农作物基因资源与遗传改良国家重大科学工程/农业部作物种质资源与生物技术重点开放实验室

出　　处：《作物学报》2008年第8期1323-1329,共7页Acta Agronomica Sinica

基　　金：国家基础研究发展计划(973计划)项目(2004CB117202);中央级公益性科研院所基本科研业务费专项(2060302-2-07)

摘　　要：利用小麦TaMyb2基因特异引物,克隆了3种类型TaMyb2的cDNA序列,分别命名为TaMyb2-Ⅰ、TaMyb2-Ⅱ和TaMyb2-Ⅲ。氨基酸序列比对结果表明,TaMyb2s的序列高度相似。系统进化树分析显示,TaMyb2s与来自大麦、水稻等的直系同源基因编码蛋白的亲缘关系较近;TaMyb2s的3种类型与小麦基因组没有明显的对应关系。实时定量PCR检测结果表明,小麦幼苗中的TaMyb2s均参与对渗透胁迫的应答反应,但表达模式不尽相同,TaMyb2-Ⅲ对渗透胁迫的应答最迅速,TaMyb2-Ⅰ次之,TaMyb2-Ⅱ最迟缓。从小麦不同发育时期幼嫩组织中TaMyb2s的表达情况推测,TaMyb2-Ⅰ和TaMyb2-Ⅲ可能主要在生长发育的前期调控下游基因,而TaMyb2-Ⅱ主要在发育后期发挥作用。MYB, one of the biggest transcription factor families, plays a crucial role in regulating cellular morphogenesis, secondary metabolism, responding to hormone and stress signals in plants. Several MYB transcription factors were involved in response to various abiotic stresses, such as drought, salinity, and low temperature. In this study, Hanxuan 10, a wheat （Triticum aestivum） cultivar with strong drought resistance, was employed to clone MYB gene using specific primers of TaMyb2. Three types of cDNA with high identities of 95.3%, 95.0%, and 99.6% to TaMyb2 were obtained, and designated TaMyb2-Ⅰ, TaMyb2-Ⅱ, and TaMyb2-Ⅲ, respectively. Structure analysis indicated that the 3 types of TaMyb2 gene contained 2 MYB DNA-binding domains, and classified to R2R3-MYB sub-family. Phylogenetic analysis based on the putative amino acid sequences indicated that TaMyb2 were closer to HvMYB4 and OsMYB4 originated from barley and rice, respectively, while had less relations to ZmMYB39 from maize （Zea mays）, AtMYB15 from Arabidopsis and NtMYB1 from tobacco （Nicotiana tabacum）. No corresponding relationships were observed between the TaMyb2s and A, B, D genomes of common wheat according to phylogenetic analysis of common wheat and its relative species T. urartu, Aegilops speltoides, Ae. tauschii, T. dicoccoides, and T. araraticum. The different expression patterns of TaMyb2s were observed using real-time quantitative PCR methods, though all the 3 types were associated with osmotic stress. TaMyb2-Ⅲ was the most sensitive to hyperosmolality, followed by TaMyb2-Ⅰ. In addition, the differential expression levels of TaMyb2s were detected in tender tissues at different developmental stages in wheat. The highest expression level of TaMyb2s was identified at seedling stage, especially in seedling roots, and then decreased gradually from seedling to heading stage. High expression levels of TaMyb2-Ⅰ and TaMyb2-Ⅲ only presented before jointing stage, while TaMyb2-Ⅱ held about 2 folds till heading stage.

关 键 词：小麦 MYB转录因子 基因克隆 非生物胁迫 基因表达 

分 类 号：S512.1[农业科学—作物学]