油莎豆液泡膜内在蛋白基因CeTIP1;1的克隆与分析  

Molecular cloning and characterization of CeTIP1;1,a gene encoding tonoplast intrinsic protein from Cyperus esculentus tubers

作　　者：郑玉皎 赵永国 常丽丽[1] 邹智 ZHENG Yu-jiao;ZHAO Yong-guo;CHANG Li-li;ZOU Zhi(Hainan Key Laboratory for Biosafety Monitoring and Molecular Breeding in Off-Season Reproduction Regions,Institute of Tropical Biosciences and Biotechnology/Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences,Haikou 571101,China)

机构地区：[1]海南省南繁生物安全与分子育种重点实验室/中国热带农业科学院热带生物技术研究所/三亚研究院,海南海口571101

出　　处：《中国油料作物学报》2024年第6期1296-1302,共7页Chinese Journal of Oil Crop Sciences

基　　金：“崖州湾”菁英人才科技专项(SCKJ-JYRC-2022-66);海南省自然科学基金(320RC705);国家自然科学基金(31971688);中央级公益性科研院所基本科研业务费专项(1630052022001)。

摘　　要：液泡膜内在蛋白(TIP)是一类定位在液泡上具有高效水分转运活性的水通道蛋白,其在植物的生长发育及逆境响应中发挥重要作用。油莎豆起源于非洲和地中海沿岸,是迄今唯一已知在块茎中高水平积累油脂的新型草本油料作物。研究基于油莎豆的基因组和转录组数据对一个块茎高水平表达的TIP基因进行了克隆和鉴定。序列分析显示,CeTIP1;1包含2个内含子,编码区长756 bp,编码251个氨基酸,含有一个水通道蛋白特有的MIP结构域,分子量为25.75 kDa、等电点为6.01、不稳定系数为24.90、总平均疏水指数为0.831、脂肪族指数为107.77,属于稳定的酸性疏水型蛋白。进化分析显示,CeTIP1;1与水稻的OsTIP1;1聚在一起,序列相似性高达92.83%,支持其归为TIP1亚类。亚细胞定位分析显示,CeTIP1;1定位在烟草叶片的液泡膜。表达分析显示,CeTIP1;1组成型表达,其在分析的所有组织中均高水平表达;在块茎的发育过程中,基因呈现先升后降的近钟形趋势。这些结果为深入解析油莎豆块茎的水分平衡机制奠定了坚实的基础。Tonoplast intrinsic proteins(TIPs),which constitute a subfamily of aquaporin facilitating the move⁃ment of water at vacuolar membranes,play a key role in growth,development,and stress response of plants.Tiger⁃nut(Cyperus esculentus),which initially originated in Africa and Mediterranean,is a novel herbaceous oil crop uniquely accumulating high levels of oil in underground tubers.Based on available genome and transcriptome data,in this study,a tuber-abundant TIP gene named CeTIP1;1 was cloned and characterized.This gene was shown to possess two introns with a coding sequence of 756 bp,putatively encoding 251 amino acids with the molecular weight of 25.75 kDa,the isoelectric point of 6.01,the instability index of 24.90,the grand average of hydropathicity of 0.831,and the aliphatic index of 107.77,implying its stable,acidic,and hydrophobic features.The protein in⁃cludes one conservative major intrinsic protein(MIP)domain specific to aquaporins.Phylogenetic analysis indicated that CeTIP1;1 clusters with OsTIP1;1 and exhibits a relatively high sequence similarity of 92.83%,supporting that it is a TIP1 homolog.Subcellular localization analysis showed that CeTIP1;1 was indeed localized to the vacuolar membrane of Nicotiana tabacum leaves.Expression analysis revealed a constitutive and high level expression of Ce⁃TIP1;1 in all tissues examined in this study.Moreover,CeTIP1;1 was shown to exhibit a bell-like expression pat⁃tern during tuber development.These results laid a solid foundation for further uncovering the mechanism of water balance in tigernut tubers.

关 键 词：油莎豆 块茎 水通道蛋白 亚细胞定位 液泡 表达模式 

分 类 号：S794.1[农业科学—林木遗传育种]