苹果赤霉素氧化酶基因GA2ox、GA3ox和GA20ox家族全基因组鉴定及表达分析  

Genome-wide Identification and Expression Analysis of GA2ox,GA3ox and GA20ox in Apple

作　　者：董凤 樊胜[1] 马小龙 孟媛 左希亚 刘小杰 李珂 刘桢 韩明玉[1] 张东[1] DONGFeng;FAN Sheng;MAXiaolong;MENGYuan;ZUOXiya;LIUXiaojie;LIKe;LIUZhen;HAN Mingyu;and ZHANG Dong(College of Horticulture, Northwest A ＆ F University, Yangling , Shaanxi 712100, China)

机构地区：[1]西北农林科技大学园艺学院,陕西杨凌712100

出　　处：《园艺学报》2018年第4期613-626,共14页Acta Horticulturae Sinica

基　　金：陕西省重点研发项目(2017NY0055);西北农林科技大学"仲英青年学者"项目;国家现代农业产业技术体系建设专项资金项目(CARS-27);国家苹果改良中心杨凌分中心项目;陕西省果业发展协同中心项目

摘　　要：通过生物信息学方法对苹果赤霉素氧化酶基因GA2ox、GA3ox和GA20ox的结构、化学性质、染色体分布、进化关系、启动子顺式作用元件和组织特异性表达进行分析,并通过实时荧光定量PCR对苹果花芽诱导过程中的表达水平进行测定。从苹果基因组里鉴定出41个赤霉素氧化酶基因,其中GA2ox类20个,GA3ox类14个,GA20ox类7个,除4号染色体外,其他染色体均有分布;其蛋白质分子量在13.15~60.17 k D之间,等电点预测值在5.50~9.81之间;通过聚类分析将这41个赤霉素氧化酶基因分为5个亚家族;基因结构和保守结构域分析发现这41个赤霉素氧化酶基因的外显子数1~5不等,且保守基序Motif 1、5、6、7、10为大部分基因所共有;根据苹果表达量数据库组织特异性分析发现这3类基因在不同品种、不同组织部位的表达量不同,其中在花和果实中表达量相对较高。通过‘长富2号’花芽诱导过程的转录组数据,挑选出8个基因(MdGA2ox4、MdGA2ox6、MdGA2ox9、MdGA2ox12、MdGA3ox5、MdGA3ox12、MdGA20ox1和MdGA20ox5)进行实时荧光定量PCR分析,结果发现,GA3处理后,花后不同时期GA20ox类氧化酶基因表达量均下调,GA2ox类氧化酶基因表达量均上调,GA3ox类氧化酶基因表达量则出现相对波动的现象。In this study,we analyzed the gene structure,chemical characterizations,chromosome locations,evolutionary relationship,promoter cis-acting element,tissue specific expression with online database. Additionally,the expression levels of GA2 ox,GA3 ox and GA20 ox were also investigated during flower induction by q RT-PCR. A total of 41 gibberellin oxidase genes were identified from the apple genome,including 20 GA2 ox,14 GA3 ox,and 7 GA20 ox. They were all distributed on all chromosomes except chromosome 4. The molecular weight is ranged from 13.15 to 60.17 k D,and the isoelectric point is ranged from 5.50 to 9.81. The 41 gibberellin oxidase genes were clustered into five subfamilies. Gene structure and conserved domain analysis showed that the number of exons of the 41 gibberellin oxidase genes were ranged from 1 to 5,and most genes shared conserved motifs 1,5,6,7,and 10. Further,tissue specific analysis by online database showed that the three types of genes were differentially expressed in different varieties and tissues,and their expression levels were relatively high in flowers and fruits. Eight candidate genes were selected for q RT-PCR through the transcriptome data. The expression of GA20 ox was down-regulated,while GA2 ox was increased at different time after flowering in GA3 treatment,the expression of GA3 ox showed different trends in different stages.

关 键 词：苹果 花芽诱导 赤霉素氧化酶 基因家族鉴定 基因表达 

分 类 号：S661.1[农业科学—果树学]