木薯MYB转录因子MeMYB2特性及功能分析  

Characterization and Function Analysis of Cassava MYB Transcription Factor MeMYB2

作　　者：杨静园 阮孟斌[2] 郭鑫[3] 彭明[2] YANG Jingyuan;RUAN Mengbin;GUO Xin;PENG Ming(Heilongjiang Bayi Agricultural University,Daqing,Heilongjiang 163000,China;Institute of Tropical Bioscience and Biotechnology,Chinese Academy of Tropical Agricultural Sciences,Haikou,Hainan 571101,China;Huazhong Agricultural University,Wuhan,Hubei 430070,China)

机构地区：[1]黑龙江八一农垦大学生命科技学院,黑龙江大庆163000 [2]中国热带农业科学院热带生物技术研究所,海南海口571101 [3]华中农业大学,湖北武汉430070

出　　处：《热带作物学报》2021年第4期936-944,共9页Chinese Journal of Tropical Crops

基　　金：国家重点研发计划项目(No.2018YFD1000501)。

摘　　要：MYB转录因子是植物最大的转录因子家族之一,其部分成员在植物非生物胁迫响应过程中发挥着重要的调控作用。通过转录组数据分析,筛选到了多个木薯干旱胁迫相关的MYB类基因,本研究针对其中的1个MYB转录因子MeMYB2展开研究。MeMYB2蛋白N末端与AtMYB60蛋白的N末端氨基酸序列具有95%以上的相似度,但其C末端氨基酸序列与AtMYB60只有30%左右的相似度。编码该蛋白的基因在木薯成熟叶片中优势表达,并且其表达受干旱胁迫负调控。MeMYB2蛋白主要定位于细胞核中,且在酵母中具有明显的转录自激活活性,其转录激活结构域在蛋白C末端247~267位点之间的20个氨基酸残基内。利用酵母双杂交系统从木薯cDNA文库中筛选到了8个与MeMYB2互作的蛋白,其中的2个蛋白与气孔运动和光合作用有关。MeMYB2-RNAi转基因木薯成熟叶片的失水率显著低于野生型木薯成熟叶片,说明MeMYB2转录因子负调控木薯叶片失水率,推测其可能具有调控气孔运动的功能。MYB transcription factor family is one of the largest transcription factor families in plants,playing key roles in stress response of many plants.Based on transcriptome data analysis,we have identified several drought-responsive MYB members from cassava(Manihot esculenta).Herein,were perform characterization and function analyses on one of these drought-responsive MYB transcription factors,namely MeMYB2.MeMYB2 had 95%amino acid similarity with AtMYB60 in its N-terminus,whereas only 30%amino acid similarity was found in their C-terminus.MeMYB2 was specifically expressed in cassava leaves and was down-regulated by drought stress.Subcellular localization analysis indicated that MeMYB2 was localized in nucleus.Furthermore,MeMYB2 showed transcriptional activity in yeast,and the transcription activated domain was located within a 20 amino acid fragment between the 247-267 AA position.Eight proteins were identified as the MeMYB2 binding protein according to the result of yeast two hybrid analysis.Two of these proteins are related to stomatal movement regulation and photosynthesis.The mature leaves of MeMYB2-RNAi transgenic cassava showed lower water loss rate than that of wild type,suggesting the roles of MeMYB2 in regulation of stomatal movement.

关 键 词：木薯 干旱胁迫 MeMYB2转录因子 

分 类 号：S533[农业科学—作物学]