毛果杨CNGC家族全基因组鉴定及胁迫响应分析

Genome-wide Identification and Stress Response Analysis of Cyclic Nucleotide-gated Channels (CNGC) Gene Family in Populus trichocarpa

植物环核苷酸门控离子通道(cyclic nucleotide-gated channels,CNGC)家族具有多种生物学功能,尤其是在植物的生长发育及逆境胁迫响应中发挥着重要的作用。本研究通过生物信息学方法及qRT-PCR对PtrCNGC家族成员蛋白的基本理化性质与结构特征、系统发育、基因结构和保守基序、启动子顺式作用元件,以及基因表达模式进行分析。结果表明:在毛果杨(Populus trichocarpa)全基因组中共鉴定出19个PtrCNGC基因,PtrCNGC家族成员可分为4个亚群(Ⅰ、Ⅱ、Ⅲ和Ⅳ亚群),其中第Ⅳ亚群分为2个亚组(Ⅳa组和Ⅳb组)。PtrCNGC基因编码的蛋白均为碱性蛋白,此外,该家族仅有1个成员为疏水性蛋白,其余成员全部为亲水性蛋白。19个PtrCNGC不均匀地分布于毛果杨的11条染色体上,剩余8条染色体上没有成员分布。PtrCNGC家族包含7对同源基因且它们之间的Ka/Ks值均远小于1。PtrCNGC家族各亚群成员之间的基因结构、蛋白保守基序分布差异较小。启动子顺式作用元件预测分析发现,PtrCNGC基因序列启动子区域存在响应多种激素以及逆境胁迫相关的作用元件。qRT-PCR结果表明,PtrCNGC家族在不同组织中的表达具有特异性,在茎中的表达量较高,在根和叶中的表达量较低;在盐胁迫和干旱胁迫下,PtrCNGC家族同一分支上的多数成员表现出相似的表达模式。本研究结果为进一步研究毛果杨CNGC家族在非生物胁迫中的功能提供参考。

The plant cyclic nucleotide-gated channels(CNGC)family has a variety of biological functions and plays an important role in the growth and development of plants and the response to stress.In this study,bioinformatics methods and q RT-PCR were used to analyze the basic physicochemical properties,structural characteristics,phylogeny,gene structure and conserved motif,cis-acting elements of the promoter and gene expression patterns of the Ptr CNGC gene family members respectively.The results showed that a total of 19Ptr CNGC genes were identified in the whole genome of Populus trichocarpa.Ptr CNGC gene family could be divided into four subgroups(Ⅰ,Ⅱ,ⅢandⅣ),and subgroupⅣcould be divided into two subgroups(Ⅳa andⅣb).The proteins encoded by the Ptr CNGC genes were all basic proteins,and only one member of the Ptr CNGC gene family was hydrophobic protein,while all the other members were hydrophilic proteins.A total of 19Ptr CNGCs were distributed unevenly on 11 chromosomes of P.trichocarpa,while the remaining 8 chromosomes had no members distributed.The Ptr CNGC gene family contained seven pairs of homologous genes and the Ka/Ks value between them was far less than one.There was little difference in gene structure and protein conserved motif distribution among the family members.Predictive analysis of cis-acting elements in the promoter region of the Ptr CNGC gene sequence showed that there were acting elements related to various hormones and stress.The q RT-PCR results showed that the expression of Ptr CNGC gene family was specific in different tissues,with higher expression levels in stems and lower expression levels in roots and leaves.Under salt stress and drought stress,most members of the same branch of the Ptr CNGC gene family showed similar expression patterns.The results of this study provid a reference for further study on the function of Ptr CNGC family in abiotic stress.