野生二粒小麦PYL基因家族的鉴定及其在逆境胁迫下的表达特性分析

脱落酸(ABA)是一类重要的植物内源激素,在调控植物生长发育和胁迫响应等方面发挥着关键作用。基因作为ABA的受体,在ABA信号转导过程中发挥着重要作用。为深入发掘野生二粒小麦PYL基因,本研究利用生物信息学对野生二粒小麦的PYL家族进行全基因组鉴定与分析。结果在野生二粒小麦基因组中共鉴定到24个PYL基因(TdPYLs),分布在1A、1B、2A、2B、3A、3B、4A、4B、7A和7B染色体上,且所有成员均含有PYR-PYL-RCAR-like功能域;系统进化分析发现,24个TdPYL基因可分为3个亚家族,同一亚家族成员间具有相似的基因结构和保守结构域;对这些PYL基因的启动子顺式元件进行预测,发现它们含有大量与逆境胁迫、光调节和ABA响应相关的元件;基于RNA-seq数据的表达特性分析发现,它们在不同组织中以及逆境胁迫下表达差异明显,并鉴定到多个与组织特异性以及胁迫响应相关的PYL基因;进一步对PYL基因的单倍型组成进行分析,发现在野生二粒小麦、栽培二粒小麦和硬粒小麦中PYL基因的遗传变异和单倍型组成具有明显的差异,发生了显著的遗传分化。本研究为深入揭示野生二粒小麦PYL基因的调控功能及其进化机制研究提供了有益信息。

Identification and Expression Analysis of PYL Gene Family in Wild Emmer Wheat(Triticum dicoccoides L.) under Abiotic Stress

Abscisic acid(ABA) is an important endogenous hormone in plant,playing the crucial role in regulating plant growth,development and stress response. Pyrabactin resistance 1 (PYR)-like(PYL) gene,as the receptor of ABA,plays an important role in ABA signal transduction. To explore the PYL gene in wild emmer wheat,the PYL family of wild emmer wheat was identified at the genome-wide level using bioinformatics method. A total of 24 PYL genes(TdPYLs) were identified in wild emmer wheat,located on 10 chromosomes,and all of which contain the conserved PYR-PYL-RCAR-like domain. Phylogenetic analysis clarified them into three subfamilies,and the members belonging to the same subfamily display similar gene structure and conserved domain composition. Prediction of the cis elements in the promoters showed that they contain a large number of elements related to stress response,ABA response as well as light response.Based on RNA-seq data,the expression patterns of PYLs in different tissues and under drought and salt stresses were investigated,and several tissue-specific or stress-responsive TaPYL genes were found. Finally,we analyzed the genetic variations and haplotype of PYL genes in different tetraploid populations. The results showed that there are significant difference in the genetic variation and haplotype composition of PYL gene in wild emmer wheat,cultivated emmer wheat and durum wheat. This study provides the useful information for further revealing the regulatory function and evolutionary mechanism of PYL genes in wild emmer wheat.