花生赤霉素3-β-双加氧酶(AhGA3ox)基因家族的全基因组鉴定及表达分析

Genome-wide identification and expression analysis of AhGA3ox gene family in peanut(Arachis hypogaea L.)

赤霉素3-β-双加氧酶(gibberellin 3-beta-dioxygenase,GA3ox)是参与赤霉素生物合成的关键酶之一,可通过影响赤霉素的形成调控植物的生长发育,目前在花生中尚无系统研究。本研究利用生物信息学方法在花生栽培种基因组数据库中筛选花生GA3ox家族基因,对鉴定出的7个AhGA3ox在栽培种花生基因组中的分布、结构及进化特征、理化性质、启动子顺式作用元件进行分析,并利用qRT-PCR技术对其进行花生组织结构表达模式分析,同时对AhGA3ox家族基因在不同荚果大小的2个花生品系中的表达量进行分析。结果表明,7个AhGA3ox基因分布在7条染色体上,均由1个内含子和2个外显子组成。花生AhGA3ox蛋白中均包含1个DIOX_N结构域和1个2OG-FeII_Oxy结构域,系统进化分析表明与大豆的亲缘关系较近,在根、茎、叶、花、果针5个组织中呈现出不同表达模式,不仅在花生果壳不同发育时期的表达量不同,在2个荚果大小不同的花生品系果壳相同发育时期的表达量也不相同,但多数发育时期在大果品系中的表达量均显著高于小果品系,推测该家族基因的表达可能对荚果的形成具有促进作用。

Gibberellin 3-beta-dioxygenase(GA3ox)is one of the key enzymes involved in gibberellin biosynthesis,which can regulate plant growth and development by affecting gibberellin formation.There were no systematic studies in peanut genome.In this study,AhGA3ox family genes were identified from the genome database of cultivated peanut species by bioinformatics,and the distribution,structure,evolutionary characteristics,physical and chemical properties,promoter cis-acting elements were also analyzed.The relative expression pattern of AhGA3oxs in different peanut tissues was analyzed by qRT-PCR,and the relative expression level of in shell of two peanut lines with different pod size were also analyzed.The results showed that 7 AhGA3oxs were distributed on 7 chromosomes of peanut,all of which were composed of 1 intron and 2 exons.All the AhGA3ox proteins contained 1 DIOX_N domain and 12OG-FeII_Oxy domain.Phylogenetic analysis showed that they were closely related to GA3ox proteins of soybean,.The AhGA3oxs showed obvious tissue expression specificity in root,stem,leaf,flower and peg.The expression levels of AhGA3oxs were not only different in different development stages of the peanut shell,but also different at the same development stage of the two lines.Interestingly,the relative expression levels in large pod lines were significantly higher than those in small pod lines at most development stages.Therefore,we predict that the gene expression of AhGA3ox gene family may promote the formation of large pod.