玉米OFP基因家族全基因组鉴定及表达分析

Genome-wide Identification and Expression Analysis of OFP Gene Family in Zea mays

OFP (OVATE family proteins)基因家族是植物特有的一类转录因子,广泛存在于植物各个组织中,参与调控植物的生长发育、抗逆等。然而在玉米研究中该家族成员未见报道。为解析OFP家族基因在玉米基因组中的特征,使用HMMER软件对玉米基因组中的OFP家族成员进行筛选,利用Pfam数据库对筛选的结果进行分析,包括基因定位、motif预测、进化分析、顺式作用元件分析及亚细胞定位预测,同时对玉米与拟南芥和水稻基因组中的OFP家族基因进行共线性、选择压力分析,最后再分析了干旱处理下穗发育过程中的家族成员基因表达水平。结果筛选到玉米OFP家族基因共43个,在10条染色体上均有分布,其中3号染色体上的数目最多为8个,5号染色体分布最少仅有1个;进化分析发现玉米OFP家族成员归为3个亚类;motif分析中共鉴定到8个motif基序,其中motif 1和motif 2为玉米OFP家族基因最保守的两段基序;在对启动子顺式作用元件分析中发现与胁迫相关的OFP基因共10个,其中有5个基因顺式作用元件与干旱胁迫相关;与拟南芥4个基因存在共线性,与水稻的17个基因存在共线性,其中玉米Zm00001d034973和水稻LOC_Os08g01190、Zm00001d038024和LOC_Os05g36990这两对基因被鉴定为存在高度同源,Zm00001d012282和Zm00001d038283在玉米中正调控响应干旱胁迫;大部分OFP基因在进化选择压力中Ka/Ks<1,受到纯化选择作用,仅有1个基因在与水稻的进化中Ka/Ks>1,在进化过程中受到选择;多个玉米家族基因被预测定位到细胞核内;干旱处理后的OFP家族基因大部分显著下调,且在穗发育阶段差异显著,其中Zm00001d038473可较早响应干旱胁迫。本研究可为玉米OFP家族基因的功能尤其响应干旱机理提供一定的研究基础。

OVATE family protein(OFP), is a type of transcription factor specific to plants, widely existed in several plants tissues, and involved in the regulation of growth and development as well as stress tolerance in p lants. However, OFP gene, haven’t been investigated completely in corn(Zea mays). In order to parse characteristics of OFP family genes in maize genome, this study used the HMMER software to screen OEP gene family members in maize genome, and further confirmed by Pfam database, It including gene location, motif prediction, evolution analysis, cis acting element analysis and subcellular localization prediction. At the same time, collinearity and selective pressure analysis were carried out for OFP family genes in maize and Arabidopsis and rice genomes. Expression patterns of OFP genes under drought stress condition were also investigated in this study. A total of 43 OFP genes were screened, which were distributed in all 10 chromosomes of Zea mays, with the maximum number of eight OFP genes on chromosome 3 and minimum number of one gene on chromosome 5;Zea mays OFP genes were classified into three sub-groups based on phylogenetic analysis and a total of eight motif were identified, among which, motif 1 and motif 2 were the most conserved motifs of OFP family genes;To further investigate the cis-regulatory elements in the promoter region of OFP genes, 10 stress related OFP genes were found, among which five were related to drought stress;4 genes and 17 genes in Zea mays were collinear with in Arabidopsis thaliana and rice, respectively, Among them, Zm00001 d034973 and Zm00001 d038024 were highly homologous with LOC_Os08 g01190 and LOC_Os05 g36990, respectively, Zm00001 d012282 and Zm00001 d038283 were positively regulated in response to drought stress in maize, For most OFP genes Ka/Ks<1, were subject to purification selection under the evolutionary selection pressure, but, Ka/Ks>1 existed only 1 gene in its evolution with rice, that was to say, it was positively selected in the evolutionary process;Multiple maize family genes were predicted to be located in the nucleus;Most of OFP genes were significantly down-regulated after drought treatment, and significant differences were found at plant panicle developmental stage, among them, Zm00001 d038473 could earlier respond to drought stress than any other members. This study would provide a basis for the study of the function of maize’s OFP family genes, Especially in response to the mechanism of drought stress.