甘薯扩展蛋白IbEXPA2基因克隆和表达分析  

Cloning and Expression Analysis of Ib EXPA2 from Sweet Potato

作　　者：蔡兆琴 龙婷晞 肖冬[1,2] 王爱勤 黄咏梅[3] 李慧峰[3] 詹洁[1,2] 何龙飞[1,2] Cai Zhaoqin;Long Tingxi;Xiao Dong;Wang Aiqin;Huang Yongmei;Li Huifeng;Zhan Jie;He Longfei(National Demonstration Center for Experimental Plant Science Education,College of Agriculture,Guangxi University,Nanning,530004;Guangxi Key Laboratory for Agro-Environment and Agro-Product Safety,Guangxi University,Nanning,530004;Maize Research Institute,Guangxi Academy of Agricultural Sciences,Nanning,530007)

机构地区：[1]广西大学农学院,植物科学国家级实验教学示范中心,南宁530004 [2]广西大学,广西农业环境与农产品安全重点实验室,南宁530004 [3]广西农业科学院玉米研究所,南宁530007

出　　处：《分子植物育种》2023年第5期1401-1407,共7页Molecular Plant Breeding

基　　金：国家自然科学基金项目(32060419);广西薯类创新团队首席专家项目(nycytxgxcxtd-11-01)共同资助。

摘　　要：扩展蛋白(Expansin)是细胞壁的重要组成成分,参与细胞壁的舒张,与植物器官生长发育密切相关。甘薯是一种块根类作物,其块根不仅是繁殖器官,也是储能器官,因此,开展甘薯块根生长膨大机理研究具有重要意义。本研究在前期转录组学研究基础上,克隆到一个可能与块根膨大相关的扩展蛋白基因IbEXPA2,并进行生物信息学和qPCR表达分析。生物信息分析表明,IbEXPA2编码253个氨基酸,包含DPBB_1和Pollen_allerg_1结构域,具有一段信号肽及23个氨基酸的跨膜结构域。该基因编码的蛋白与三裂叶薯expansin-A4蛋白(登录号:XP_031109781.1)的同源性最高,为98.03%;时空表达分析表明该基因在甘薯品种‘西瓜红’和‘桂经薯8号’块根中表达显著高于纤维根,‘西瓜红’生长的各个时期块根中表达均显著高于茎和叶,在移栽50 d时表达量最高,为对照纤维根的8.49倍;‘桂经薯8号’生长多数时期在块根中的表达也显著高于茎和叶,在移栽35 d时表达量最高,为对照的8.11倍。推测该基因参与甘薯块根生长膨大调控。Expansin is an important component of cell wall, which participates in the relaxation of cell wall and is closely related to the growth and development of plant organs. Sweet potato is a kind of root tuber crop, and its root tuber is not only a reproductive organ, but also an energy storage organ, so it is of great significance to study the mechanism of root tuber expansion of sweet potato. On the basis of previous transcriptome studies, an expansin protein gene IbEXPA2, which may be related to root expansion, was cloned in this study. Bioinformatics and qPCR techniques were used to analyze the gene. Bioinformatics analysis showed that IbEXPA2 encoded 253 amino acids, including DPBB_1 and Pollen_allerg_1 domains, a signal peptide and a transmembrane domain with 23amino acids. The protein encoded by this gene has the highest homology at 98.03% with the three-leaf split potato expansin-A4 protein(Accession number: XP_031109781.1). The spatio-temporal expression analysis showed that IbEXPA2 expressed significantly in root tuber than in fibrous root of sweet potato cultivar ’Xiguahong’ and ’Guijingshu8’. The expression of IbEXPA2 was significantly higher in root tuber than in stem and leaf in ’Xiguahong’different growth stages, with 8.49 times of control at 50 days after transplanting at the highest expression level.The expression of IbEXPA2 of many growth stages was significantly higher in root tuber than in stem and leaf also in ’Guijingshu8’, with 8.11 times of control at 35 days after transplanting at the highest expression level. Therefore,it is speculated that IbEXPA2 participates in the growth regulation of root tuber in sweet potato.

关 键 词：扩展蛋白 生信分析 表达分析 块根 甘薯 

分 类 号：S531[农业科学—作物学]