玉米HSP70基因家族的全基因组鉴定与分析

Genome-wide Identification and Analysis of HSP70 Gene Family in Maize

热激蛋白70(HSP70)是生物体应答各种胁迫反应产生的一类蛋白,广泛存在于生物体中,在几乎所有的活细胞中都起着重要的作用。为全面解析玉米基因组HSP70基因信息,利用从Pfam数据库中下载的隐马氏模型文件PF00012在Gramene数据库进行基因搜索,并利用多种生物软件或在线工具对所鉴定的基因进行生物信息学分析。结果表明,试验共鉴定得到35个玉米HSP70基因,分别命名为Zm HSP70-1~Zm HSP70-35。这些基因不均衡地分布在玉米的10条染色体上,其中5号染色体上分布最多(6个),9号染色体上分布最少(1个)。进化树分析显示35个基因聚为6组,且同组基因具有相似的基因结构,其基序数量、类型和顺序也是相似的。物种间进化树分析不同物种的86个基因,存在8对直系同源基因和17对旁系同源基因,直系同源基因中7对存在于玉米和水稻之间,仅1对存在于水稻和拟南芥之间,说明起源于共同祖先基因的直系同源基因对虽在单/双子叶植物差异分离前就存在,但玉米与水稻间的进化关系要比与拟南芥间更为亲近。表达谱分析表明,大多数Zm HSP70基因属组成型表达,但表达模式和表达量不同。本研究结果为进一步研究玉米HSP70家族基因的功能奠定了理论基础。

Heat shock protein 70（ HSP70） is a group of proteins induced by various environmental stresses,and exist in nearly all living organisms. To comprehensively analyze information for the Zm HSP70 genes of maize genome,HSP70domain（ PF00012） downloaded from Pfam database was employed to identify Zm HSP70 genes in Gramene database.The obtained amino acid sequences were analyzed with the bioinformatics software or tools online. Totally 35 Zm HSP70 genes were found in maize genome and named from Zm HSP70-1 to Zm HSP70-35. These genes were distributed unequally in ten chromosomes of maize,the maximum of Zm HSP70 genes were found on chromosomes 5（ six genes）and only 1 gene was located on chromosomes 9. The result of gene structures and phylogenetic analysis revealed that 35 Zm HSP70 genes were classified into six group and the type,order,and number of motifs were similar in proteins with in the same group,but were differed from the proteins in other groups. The combined phylogenetic tree revealed that there were 8 pairs of orthologous genes and 17 pairs of paralogous genes among 86 HSP70 members in different organism.Among which 7 pairs of orthologous genes from maize and rice and 1 pair from rice and Arabidopsis. These results suggested that the orthologous pair originated from the common ancestral genes existed before the divergence of the monocots and dicots. Expression profile analysis indicated that most of Zm HSP70 genes were expressed constitutively,but expression patterns and expression quanlities were different. These results could provide a theoretical basis for further research on the function analysis of Zm HSP70 gene family.