芒果赤霉素氧化酶基因GA3ox的克隆、表达及亚细胞定位分析  

Cloning,Subcellular Localization and Expression Analysis of GA3ox Gibberellin Oxidase Gene in Mango

作　　者：张宇 黄国弟 荣涛 张继[1] 郑剑 赵英 唐玉娟 赵志常[2] ZhangYu;HuangGuodi;Rong Tao;Zhang Ji;Zheng Jian;Zhao Ying;Tang Yujuan;Zhao Zhichang(Guangxi Subtropical Crops Research Institute,Guangxi Academy of Agricultural Sciences,Nanning,530001;Tropical Crops Genetic Resources Institute,Chinese Academy of Tropical Agricultural Sciences,Haikou,571101)

机构地区：[1]广西壮族自治区农业科学院,广西壮族自治区亚热带作物研究所,南宁530001 [2]中国热带农业科学院热带作物品种资源研究所,海口571101

出　　处：《分子植物育种》2023年第4期1111-1116,共6页Molecular Plant Breeding

基　　金：国家重点研发计划项目(2019YFD1001103);中央引导地方科技发展资金项目(桂科ZY21195011);广西农业科学院基本科研业务专项(桂农科2021YT140;桂农科2020YM53);广西农业科学院科技发展基金项目(桂农科2020YM131)共同资助。

摘　　要：赤霉素3-氧化酶(gibberellin 3-oxidases,GA3ox)是赤霉素(gibberellic acid,GA)生物合成途径中的关键限速酶之一。芒果中GA3ox基因的功能及其表达模式未见报道。本研究利用RACE技术克隆了一个芒果GA3-氧化酶基因(GA3ox),该基因全长cDNA序列为1680 bp,编码氨基酸381个,开放阅读框(open reading frame,ORF)为1146 bp,蛋白分子量为42.6 kD,等电点为5.13,不含信号肽,不含跨膜结构域。系统发育树分析发现,该基因编码的蛋白主要与开心果亲缘关系较近,其次为克莱门柚、甜橙、麻疯树等植物。通过拟南芥原生质体亚细胞定位分析发现,该基因主要定位在细胞质中。通过对乔化、矮化芒果品种不同发育时期的叶片的实时荧光定量PCR分析发现,该基因主要在矮化品种中表达量较高,在乔化品种各个时期表达量较低,且差异不大。矮化品种中主要在开花期表达量最高,坐果期7~8周含量最低,但都高于乔化品种的任何取样时期。该基因的克隆和表达分析为下一步功能的研究及其在芒果株形调控分子机制提供理论依据。Gibberellin 3-oxidases(GA3ox)is one of the key rate-limiting enzymes in the biosynthetic pathway of gibberellic acid(GA).The function and expression pattern of GA3ox gene in mango have not been reported.In this study,a mango GA3-oxidase gene(GA3ox)was cloned using RACE technology.The full-length cDNA sequence of the gene is 1680 bp and contains an open reading frame(ORF)of 1146 bp,which encodes 381 amino acids and has a protein molecular weight.It is 42.6 kD,isoelectric point is 5.13,no signal peptide,no transmembrane domain.Phylogenetic tree analysis revealed that the protein encoded by this gene is mainly closely related to pistachios,followed by Clementine pomelo,sweet orange,Jatropha curcas and other plants.Through analysis of the subcellular localization of Arabidopsis protoplasts,it was found that the gene was mainly localized in the cytoplasm.Through real-time fluorescence quantitative PCR analysis of the leaves of arborized and dwarfed mango varieties at different developmental stages,it was found that the gene was mainly expressed in dwarf varieties at a higher level,and the expression level of arborized varieties was lower at each stage,and the difference was not significant.Among the dwarf varieties,the expression level was highest during the flowering period,and the lowest content during the 7~8 weeks of fruit setting,but they were higher than any sampling period of the arborized varieties.The cloning and expression analysis of this gene provide a theoretical basis for the next function study and the molecular mechanism of mango plant shape regulation.

关 键 词：芒果 GA3ox 基因克隆 亚细胞定位 表达分析 

分 类 号：S667.7[农业科学—果树学]