中国辣椒BCAT基因家族鉴定、表达分析及克隆  

Identification, Expression Analysis and Cloning of Capsicum chinense BCAT Gene Family

作　　者：谢炳春 黄俊霖 温松森 李涛[2] 李颖[2] 徐小万[2] 徐晓美[2] 吴智明[1] 衡周 XIE Bingchun;HUANG Junlin;WEN Songsen;LI Tao;LI Ying;XU Xiaowan;XU Xiaomei;WU Zhiming;HENG Zhou(College of Horticulture and Landscape Architecture,Zhongkai University of Agriculture and Engineering,Guangzhou 510225,China;Vegetable Research Institute,Guangdong Academy of Agricultural Sciences/Guangdong Key Laboratory for New Technology Research of Vegetables,Guangzhou 510640,China)

机构地区：[1]仲恺农业工程学院园艺园林学院,广东广州510225 [2]广东省农业科学院蔬菜研究所/广东省蔬菜新技术研究重点实验室,广东广州510640

出　　处：《广东农业科学》2022年第12期34-43,共10页Guangdong Agricultural Sciences

基　　金：国家自然科学基金(32072598);广东省重点建设学科科研能力提升项目(2021ZDJS004);贵州省自然科学技术基金项目(黔科合基础[2018]1184);广东省省级乡村振兴战略专项(粤财农[2021]37号)。

摘　　要：【目的】了解中国辣椒(Capsicum chinense Jacq.)BCAT基因家族成员的分布、性质及表达模式。中国辣椒是辣椒的5个主要栽培种之一,果实通常具有由支链酯类形成的浓郁果香。支链氨基酸转氨酶(BCAT,Branched-chain Aminotransferase)负责催化支链氨基酸合成相应2-氧代酸,是催化合成支链酯类的第一步反应酶。【方法】使用生物信息学分析和实时荧光定量PCR等方法对中国辣椒的BCAT基因家族成员进行鉴定、表达分析和克隆。【结果】获得5个BCAT基因家族成员,分别命名为CcBCAT1、CcBCAT2、CcBCAT3、CcBCAT4和CcBCAT5,随后对其进行生物信息学分析并克隆CcBCAT1~CcBCAT4。生物信息学分析显示,这些基因分布于辣椒的4条染色体上,蛋白均为亲水性蛋白,氨基酸长度在184~557 aa,分子量为20.29~89.60 ku,等电点为5.57~8.34。亚细胞定位预测结果显示,CcBCAT1定位于叶绿体和线粒体,其他基因家族成员均位于叶绿体。CcBCATs基因时空表达分析显示,CcBCAT1-4基因具有组织表达特异性,CcBCAT2~CcBCAT4相对表达量随着辣椒的成熟呈现逐步上升的趋势,其中CcBCAT4最为明显、CcBCAT1则相反、CcBCAT5未检测到表达。【结论】明确中国辣椒BCAT基因家族的表达模式,推测CcBCAT4参与辣椒果实相关次生代谢物合成。【Objective】The purpose of this study is to understand the distribution, properties and expression patterns of members of the BCAT(Branched-chain Aminotransferase) gene family, so as to lay a foundation for further research on the function of Capsicum chinense Jacq BCAT genes. C. chinense is one of the five main cultivars of pepper.Its fruit usually has a strong fruity aroma formed by branched chain esters. BCAT is responsible for catalyzing the synthesis of corresponding 2-oxo acids from branched-chain amino acids, and is the first reaction enzyme to catalyze the synthesis of branched-chain esters. 【Method】The BCAT gene family members of C. chinense were identified, expressed and cloned using bioinformatics analysis and real-time quantitative PCR. 【Result】Five members of the BCAT gene family were obtained and named as CcBCAT1~CcBCAT5, and then bioinformatics analysis and CcBCAT1-CcBCAT4 cloning were performed on them. Bioinformatics analysis showed that these genes were distributed on the four chromosomes of pepper, and the proteins were all hydrophilic proteins with amino acid lengths ranging from 184 aa to 557 aa, molecular weights ranging from 20.29 ku to 89.60 ku, and isoelectric points ranging from 5.57~8.34. Subcellular localization prediction results showed that CcBCAT1was located in chloroplast and mitochondria, and other gene family members were located in chloroplast. The spatiotemporal expression analysis of CcBCATs genes showed that CcBCAT1-4 genes had tissue expression specificity. The regular expression of CcBCAT4 gradually increased with the maturity of pepper, and the accumulation trend of branched-chain amino acid derivatives related to pepper fruit was similar. CcBCAT5 was not detected. 【Conclusion】In conclusion, this study clarified the expression pattern of the BCAT gene family in Chinese pepper, speculated that CcBCAT4 was involved in the synthesis of secondary metabolites related to pepper fruit.

关 键 词：中国辣椒 支链氨基酸 生物信息学 表达特征 基因克隆 

分 类 号：S641.3[农业科学—蔬菜学]