Abstract:

IQM genes are important branch of the calmodulin-binding protein family that plays an important role in plant growth，development and stress response. In this study， 23 IQM gene family members were identified in the whole wheat genome using bioinformatics methods， and their chromosomal location， physicochemical properties， phylogenetic relationships， gene structure， protein conserved structural domains， promoter cis-acting elements and gene expression characteristics were systematically analysed. The results showed that the TaIQM gene family members were randomly distributed on the 18 chromosomes of wheat， and their subcellular localization showed that all genes were located in the nucleus. Phylogenetic analysis classified them into three subclasses with high similarity in gene structure and protein conserved structural domains among， and presumably similar functions； cis-acting element analysis showed that the promoters of TaIQM gene family members contained a variety of cis-acting elements related to stress， growth and development. Transcriptome analysis showed that the TaIQM gene family members were significantly differentially expressed in roots， stems， leaves， spikes and seeds at different times. qRT-PCR analysis showed that TaIQM genes were up- or down-regulated in response to various stresses such as drought， low and high temperature， NaCl and ABA in the above- and below-ground parts of wheat seedlings. It was tentatively concluded that these genes might be involved in abiotic stress regulatory through the Ca²⁺ signalling pathway. The results of this study provided clues for a comprehensive analysis of the structure and biological functions of TaIQM genes， the molecular mechanisms of abiotic stress response.

Key words: wheat, IQM gene family, gene indentification, abiotic stress

摘要：

IQM基因是钙调素结合蛋白家族中的重要分支，在植物生长发育和应激反应中发挥重要作用。本研究利用生物信息学方法在小麦全基因组中鉴定出23个IQM基因家族成员，对其染色体位置、理化性质、系统进化关系、基因结构、蛋白保守结构域、启动子顺式作用元件和基因表达特性等进行了系统分析。结果表明，TaIQM基因家族成员随机分布在小麦18条染色体上，亚细胞定位结果显示所有基因均位于细胞核中，系统进化分析将其分为3个亚类，同一亚类间基因结构、蛋白保守结构域相似度较高，推测其功能相似；顺式作用元件分析表明，TaIQM基因家族成员启动子中含有多种与逆境胁迫及生长发育相关顺式作用元件；转录组数据分析显示，TaIQM基因家族成员在不同时期的根、茎、叶、穗和籽粒中表达量存在显著性差异；qRT-PCR分析显示，在小麦苗期地上部和地下部，TaIQM基因响应干旱、低温、高温、NaCl、ABA等多种胁迫，显示上调或下调表达。初步推断这些基因可能通过Ca²⁺信号通路参与非生物胁迫调控，研究结果为全面解析TaIQM基因结构与生物学功能、非生物胁迫响应分子机制提供依据。

关键词: 小麦, IQM家族, 基因鉴定, 非生物胁迫