花楸树HSP70基因家族鉴定及其应答非生物胁迫表达分析

Genome-wide Investigation of Heat Shock Protein 70 Gene Family in Sorbus pohuashanensis and Their Expression Analysis in Response to Abiotic Stresses

热激蛋白70(heat shock protein 70,HSP70)在植物生长发育和非生物胁迫响应过程中发挥着重要作用。研究HSP70基因家族,能够弥补花楸树(Sorbus pohuashanensis)抗性相关基因研究的不足。本研究利用生物信息学方法对花楸树基因组中的HSP70基因家族进行了鉴定,并对其基因结构、系统发育关系、染色体定位和非生物胁迫下的表达进行了分析。分析结果表明,花楸树基因组中共包含22个HSP70基因家族成员,它们不均匀地分布在13条染色体上,根据系统发育关系将其分为5组,较多分组中的基因都具有相似的基因结构和保守基序。从22个HSP70基因中鉴定到两对串联重复基因和涉及13个基因的13个片段重复事件,且每一对基因的Ka/Ks值都小于1,说明花楸树HSP70基因家族在进化过程中受到了纯化作用。花楸树HSP70基因的启动子区域中存在多种与非生物胁迫相关的顺式作用元件,且随机挑选的6个HSP70基因对高温、NaCl盐以及干旱胁迫都具有不同程度的响应。这些研究结果为HSP70基因的功能分析以及花楸树的遗传改良奠定了理论基础。

Heat shock protein 70(HSP70)plays an important role in plant growth,development and abiotic stress response.The study of HSP70 gene family can make up for the lack of research on resistance-related genes in Sorbus pohuashanensis.In this study,the HSP70 gene family was identified from the genome of S.pohuashanensis using bioinformatics methods,and their gene structures,phylogenetic relationships,chromosome location,expression patterns under abiotic stress were analyzed.The results showed that a total of 22 HSP70 gene family members were identified from S.pohuashanensis,which were unevenly distributed on 13 chromosomes and divided into 5 groups according to their phylogenetic relationship,and the genes in most groups had similar gene structure and conservative motif.Two pairs of tandem repeat genes and 13 segmental duplication events involving 13 genes were identified from 22 HSP70 genes,and each pair of genes had a Ka/Ks ratios<1,indicating that the HSP70 gene family was purified during evolution.There were many cis-acting elements related to abiotic stress in the promoter region of HSP70 gene of S.pohuashanensis,and the six randomly selected HSP70 genes had different degrees of response to high temperature,NaCl salt and drought stress.This study laid a foundation for the functional analysis of HSP70 genes and the genetic improvement of the S.pohuashanensis.