罗慧婷　吕天晓　范甜　谢楚萍　周玉萍　田长恩

【摘 要】拟南芥IQM1为一个Ca2+不依赖型的钙调素结合蛋白，由AT4G33050编码，包含1个IQ基序。本实验室的前期研究发现，IQM1介导光和非生物胁迫信号的转导，参与气孔开放和根生长发育的调节。为了探讨IQM1调控这些生理进程的分子机制，本研究构建了IQM1与GAL4 DNA结合域BD的融合诱饵蛋白BD-IQM1质粒，与拟南芥幼苗cDNA的GAL4系统酵母双杂交文库AD质粒共转化AH109酵母，经过初筛、复筛、测序得到了14个候选互作蛋白，经过一对一酵母双杂交互作验证，初步确定编码基因At5g51570和转录因子TCP21都与IQM1蛋白存在互作关系。

【关键词】IQM1；拟南芥；TCP21；互作蛋白

中图分类号： Q946 文献标识码： A 文章编号： 2095-2457（2018）09-0083-002

DOI：10.19694/j.cnki.issn2095-2457.2018.09.039

Screening and Verification of the Protein Interacting with IQM1 in Arabidopsis

LUO Hui-ting LV Tian-xiao FAN tian XIE Chu-ping ZHOU Yu-ping TIAN Chang-En*

（Guangzhou Key Laboratory for Functional Study on Plant Stress-Resistant Genes，Guangzhou University，Guangzhou Guangdong 510006）

【Abstract】The IQM1 protein encoded by Arabidopsis thaliana AT4G33050 is a Ca2+-independent calmodulin-binding protein containing an IQ motif.Our previous study found that IQM1 mediates the transduction of light and abiotic stress signals and participates in the regulation of stomatal opening and root growth.In order to investigate the biomolecular mechanism of IQM1 involved in Arabidopsis thaliana，we first constructed the fusion bait protein BD-IQM1 between IQM1 and GAL4 DNA binding domain BD，and the Arabidopsis yeast cDNA library GAL4 system yeast two-hybrid library AD plasmid The transformed AH109 yeast was screened，screened，and sequenced to obtain 14 encoded proteins.After confirmation by one-to-one yeast two-hybrid experiment，the interaction between At5g51570 and TCP21 was preliminarily confirmed to have an interaction with IQM1 protein.

【Key words】IQM1；Arabidopsis thaliana；TCP21；Interaction protein

0 前言

拟南芥IQM家族共有6个成员，即IQM1-IQM6，均只含有1个能与钙调素结合的 IQ 基序（氨基酸序列为IQXXXRGXXXR），N-端與豌豆重金属诱导蛋白6A（Pea HeavyMmetalInducedProtein 6A，PHMIP 6A）同源，C-端与天花粉素（Trichosantin）同源[1]。其中，IQM1由At4g33050编码。通过酵母双杂交和双分子荧光互补实验证明IQM1在体内、外都能与CaM结合，蛋白截短实验证明IQ基序是其钙调素结合所必需的结构域[2]。本实验室对IQM1进行了初步研究，发现该基因主要在根成熟区的皮层、叶片气孔保卫细胞和表皮毛中表达，iqm1突变体表现为根伸长减慢以及对光、暗和脱落酸诱导的气孔运动不敏感的表型，且突变体气孔中活性氧含量增高[2]。过量表达IQM1基因使光诱导下气孔开度明显比野生型和iqm1-1大，在暗诱导下气孔开度则显著变小，且主根比野生型和iqm1-1长，这表明了IQM1在植物气孔运动和根系生长起着重要作用[3]。其次，本实验室还发现IQM1可能介导JA信号参与植物气孔防卫[4-5]。……