棉花Trihelix转录因子GhGT29基因的克隆及功能分析  

Cloning and functional analysis of the cotton Trihelix transcription factor GhGT29

作　　者：李月[1] 刘晓东[1] 董永梅[2] 谢宗铭[2] 陈受宜[3] 

机构地区：[1]新疆农业大学农学院,农业生物技术重点实验室,乌鲁木齐830052 [2]新疆农垦科学院生物技术研究所,作物种质创新与基因资源利用兵团重点实验室,石河子832000 [3]中国科学院遗传与发育生物学研究所,国家植物基因组重点实验室,北京100101

出　　处：《遗传》2015年第12期1218-1227,共10页Hereditas（Beijing)

基　　金：国家转基因生物新品种培育科技重大专项(编号:2009ZX08009-090B);国家自然科学基金项目(编号:31470289);新疆农业大学校前期课题(编号:XJAU201311)资助

摘　　要：Trihelix转录因子在植物抵御各种逆境胁迫中扮演重要作用,克隆棉花Trihelix转录因子基因并分析其表达特性和功能,为最终利用转基因手段改良棉花抗逆性奠定基础。本文依据生物信息学分析,采用RT-PCR方法从陆地棉中克隆了一个Trihelix转录因子基因,命名为GhGT29(Gen Bank登录号:JQ013097)。该基因最大开放阅读框(ORF)为1092 bp,编码363个氨基酸,预测分子量为40.9 k Da,等电点为5.45。SMART蛋白结构预测发现,该蛋白含有1个Trihelix家族典型的SANT结构域。系统进化树分析表明,GhGT29属于Trihelix转录因子SH4亚家族,与拟南芥At SH4-like1、At SH4-like2亲缘关系最近。实时荧光定量PCR结果表明,GhGT29受高盐、干旱、低温胁迫和ABA诱导表达;GhGT29在陆地棉的根、茎、叶、花、开花后当天胚珠以及开花后12 d(12 DPA)纤维中均有表达,其中在花中表达量最高,在茎中表达量最低。利用拟南芥原生质体系统进行分析,结果显示GhGT29主要定位于细胞核中,并且具有转录激活活性。以上结果表明GhGT29基因可能参与棉花逆境信号通路中对抗逆功能基因表达的调控。Trihelix transcription factors are important proteins involved in response to abiotic stresses in plants. Understanding the molecular mechanisms of Trihelix in cottons will lay the foundation to improve stress tolerance by gene engineering. In this study, a gene encoding Trihelix transcription factor was isolated in upland cottons using reverse transcription PCR according to bioinformatic analysis. The gene was named as GhGT29（Gen Bank accession No. JQ013097）, which was 1 092 bp, contained a 1 089 bp open reading frame and encoded a protein of 363 amino acids with a predicted molecular weight of 40.9 k Da and a isoelectric point of 5.45. SMART analysis showed GhGT29 contained one typical SANT motif. Phylogenetic analysis showed that GhGT29 belonged to the SH4 subfamily of the Trihelix family and was most closely related to At SH4-like1 and At SH4-like2. Quantitative real-time PCR（q RT-PCR） analysis revealed that GhGT29 was induced by high salt, drought, cold and abscisic acid. The expression profile also revealed that GhGT29 was constitutively expressed in all tested tissues, such as roots, stems, leaves, flowers, ovules（0 DPA） and fibers（12 DPA）. The expression level of GhGT29 was the highest in flowers and the lowest in stems. Using the Arabidopsis protoplasts assay system, we found that the GhGT29 protein was located in cell nuclei and had trans-activation activity. These results revealed that GhGT29 might be involved in the regulation of stress resistance-related genes in stress signaling pathways in upland cottons.

关 键 词：棉花 Trihelix转录因子 非生物胁迫 亚细胞定位 转录激活 

分 类 号：S562[农业科学—作物学] Q943.2[生物学—植物学]