木薯MeUGT85K4 基因的克隆和功能分析  

Cloning and Function Analysis of MeUGT85K4 Gene in Manihot esculenta

作　　者：赵平娟[1] 郭鑫[1] 林晨俞 张秀春[1] 王海燕[1] 彭明[1] Zhao Pingjuan;Guo Xin;Lin Chenyu;Zhang Xiuchun;Wang Haiyan;Peng Ming(Key Laboratory of Biology and Genetic Resources of Tropical Crops,Ministry of Agriculture,Institute of Tropical Bioscience and Biotechnology,Chinese Academy of Tropical Agricultural Sciences,Haikou,571101)

机构地区：[1]中国热带农业科学院热带生物技术研究所,农业农村部热带作物生物学与遗传资源利用重点实验室,海口571101

出　　处：《分子植物育种》2021年第14期4585-4591,共7页Molecular Plant Breeding

基　　金：国家自然科学基金(31701509);国家重点研发计划(2019YFD1001100)共同资助。

摘　　要：木薯UDP-糖基转移酶隶属于糖基转移酶大家族,负责催化糖基化反应,参与木薯亚麻苦苷的合成,在干旱胁迫的木薯叶片中大量累积。为了研究木薯UDP-糖基转移酶的功能,本研究从木薯栽培种‘SC124’中克隆了编码其的一个UDP-糖基转移酶基因,将其命名为MeUGT85K4。该基因基因组DNA全长1604 bp,包含2个外显子和1个内含子,CDS区全长为1452 bp,氨基酸序列具有氰醇Beta-葡糖基转移酶保守结构域。经过RT-qPCR(Real-time quantitative PCR detecting system)检测发现MeUGT85K4基因在一年生木薯的根、花、茎和果中高表达,在叶、块根和种子中低表达。MeUGT85K4基因可响应干旱、脱落酸(ABA)、PEG(Polyethylene glycol 6000)处理,且在处理后不同时间的木薯的根和叶中上调表达。通过构建pGBKT7-MeUGT85K4诱饵载体,从木薯干旱和低温混合库中筛选到6个与MeUGT85K4互作的候选蛋白,包括IAA-amino acid hydrolase ILR-like 6(MeIL)、Mitochondrial transcription termination factor(MeMTERF)、Lipid-transfer proteinsfamily(MeLTP)和Copper binding proteins(MeCBP)共4个已知蛋白和2个未知蛋白,其中,MeLTP在干旱胁迫条件下的木薯叶片中下调表达,而MeCBP在干旱胁迫条件下的木薯叶片中上调表达,以上结果表明MeLTP,MeCBP和MeUGT85K4可能共同参与木薯干旱响应。本研究为下一步研究木薯抗旱分子机制提供参考依据,为木薯抗旱遗传改良提供新基因资源。Cassava UDP-glycosyltransferase belongs to a large family of glycosyltransferases,which catalyzes glycosylation and participates in the synthesis of linamarin in cassava.It accumulates in cassava leaves under drought stress.In order to study the function of UDP-glycosyltransferase in cassava,MeUGT85K4 encoding UDP-glycosyltransferase was cloned from cassava cultivar'SC124'.The genomic DNA of MeUGT85K4 gene was 1604 bp,including two exon regions and one intron,and the CDS region was 1452 bp.The amino acid sequence has a conserved domain of cyanohydrin beta-glucosyltransferase.The MeUGT85K4 gene is highly expressed in fibrous roots,flowers,stems and fruits,and is low expressed in leaves,tuberous roots and seeds in a-year-old cassava.The RT-qPCR results show that MeUGT85K4 is up-regulate in roots and leaves under drought,ABA and PEG treatment cassava.The bait vector pGBKT7-MeUGT85K4 is constructed and the interaction proteins of MeUGT85K4 are screened in cassava drought and cool library by yeast two-hybrid system.The results show that six candidate proteins interacting with MeUGT85K4 were screened from cassava drought and low temperature mixture libraries,including four known proteins,IAA-amino acid hydrolase ILR-like 6(MeIL),Mitochondrial transcription termination factor(MeMTERF),Lipid-transfer proteins family(MeLTP),Copper binding proteins(MeCBP)and two unknown proteins.MeLTP is down-regulated while MeCBP is up-regulated in cassava leaves under drought stress.This result indicates that MeLTP,MeCBP and MeUGT85K4 proteins may be involved in response to drought in cassava together.This study provides a reference basis for further research on the molecular mechanism of cassava drought resistance,and provides a new genetic resource for genetic improvement of cassava drought resistance.

关 键 词：木薯 MeUGT85K4基因 功能分析 干旱响应 互作蛋白 

分 类 号：S533[农业科学—作物学]