玉米逆境胁迫响应基因ZmbZIP15的克隆与抗旱功能分析

Cloning and Drought Resistance Function Analysis of Maize Stress Response Gene ZmbZIP15

从转录组数据中筛选到27个参与干旱-复水胁迫响应的bZIP基因,构建共表达网络图。结果发现,ZmbZIP15处于核心节点位置,该基因位于第5号染色体,编码176个氨基酸,包含高度保守的bZIP结构域,属于亲水性蛋白。蛋白进化树分析发现,该蛋白与芒草、高粱的亲缘关系最近,与大麦、小麦的亲缘关系最远。ZmbZIP15基因ATG上游2 K启动子的顺式元件分析,发现含有多个参与调控脱落酸、低温和干旱的结合元件。实时荧光定量PCR(qRT-PCR)结果显示,ZmbZIP15是组成型表达基因,在雌穗高表达,幼茎的表达量最低。干旱、高温、盐、氮胁迫处理下,该基因的表达量显著上调,说明ZmbZIP15基因积极参与并调控非生物胁迫途径。过表达ZmbZIP15转基因拟南芥抗旱性检测分析,发现干旱胁迫处理下过表达ZmbZIP15基因能够提高拟南芥幼苗的抗旱性。亚细胞定位显示,该基因编码的蛋白定位于细胞核。

Twenty-seven bzIP genes involved in the response to drought-rewater stress were screened from transcriptome data,and ZmbZIP15 was found to be at the core node by constructing co-expression network map.The gene is located on chromosome 5,encoding 176 amino acids and contains a highly conserved bzIP domain,which is a hydrophilic protein.The analysis of the protein evolution tree showed that the protein was the closest relative to miscanthus and sorghum,and the furthest relative to barley and wheat.Cis-element analysis of the 2 K promoter upstream of ATG of ZmbZIP15 gene revealed multiple binding elements involved in the regulation of abscisic acid,low temperature,and drought.The results from real-time quantitative fluorescence PCR(qRT-PCR)showed that ZmbZIP15 was a constitutive expression gene,which was highly expressed in female panicle and lowest in young stem.Under drought,high temperature,salt and nitrogen stress,the expression of ZmbZIP15 gene was significantly up regulated,indicating that ZmbZIP15 gene actively participated in and regulated abiotic stress pathways.It was found that overexpression of ZmbzIP15 gene could improve the drought resistance of Arabidopsis thaliana seedlings under drought stress.Subcellular localization analysis revealed that the protein encoded by this gene is located in the nucleus.