中国农业科学 ›› 2017, Vol. 50 ›› Issue (13): 2411-2422.doi: 10.3864/j.issn.0578-1752.2017.13.001

• 作物遗传育种·种质资源·分子遗传学 •    下一篇

小麦锌指转录因子TaDi19A对低温的响应及其互作蛋白的筛选

茹京娜1,2,于太飞2,陈隽2,陈明2,周永斌2,马有志2,徐兆师2,闵东红1

 
  

  1. 1西北农林科技大学/旱区作物逆境生物学国家重点实验室,陕西杨凌712100;2中国农业科学院作物科学研究所/农作物基因资源与基因改良国家重大科学工程/农业部麦类生物学与遗传育种重点实验室,北京100081
  • 收稿日期:2017-01-23 出版日期:2017-07-01 发布日期:2017-07-01
  • 通讯作者: 闵东红,E-mail:mdh2493@126.com。徐兆师,E-mail:xuzhaoshi@caas.cn
  • 作者简介:茹京娜,E-mail:rujingna1993@163.com
  • 基金资助:
    国家转基因生物新品种培育科技重大专项(2014ZX08009-016B)、国家自然科学基金(31371620)、西北农林科技大学唐仲英育种基金

Response of Wheat Zinc-Finger Transcription Factor TaDi19A to Cold and Its Screening of Interacting Proteins

RU JingNa1,2, YU TaiFei2, CHEN Jun 2, CHEN Ming2, ZHOU YongBin2, MA YouZhi2XU ZhaoShi2, MIN DongHong1   

  1. 1 Northwest A & F University/State Key Laboratory of Crop Stress Biology for Arid Areas, Yangling 712100, Shaanxi; 2 Institute of Crop Science, Chinese Academy of Agricultural Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement/ Key Laboratory of Biology and Genetic Improvement of Triticeae Crop, Ministry of Agriculture, Beijing 100081
  • Received:2017-01-23 Online:2017-07-01 Published:2017-07-01

摘要: 【目的】锌指类转录因子在植物逆境信号转导和非生物胁迫响应中发挥重要的作用。通过对小麦锌指转录因子基因TaDi19A的耐冷性能进行鉴定,利用酵母双杂交技术筛选并获得与TaDi19A互作的候选蛋白,以解析TaDi19A介导的抗逆调控机制。【方法】通过对低温处理的小麦转录组测序结果进行分析,获得一个锌指类转录因子TaDi19A。利用生物信息学的方法分析TaDi19A的分子特性,用SMART在线工具进行蛋白结构分析;用GSDS和PHYRE2在线工具分别对TaDi19A结构和蛋白三级结构进行分析;用NetPhos 2.0 Server数据库预测TaDi19A蛋白磷酸化位点。以低温处理的小麦cDNA作为模板,通过SYBR Green染料法进行实时荧光定量PCR,检测TaDi19A在低温处理不同时间段的表达模式。构建植物表达载体pBI121-TaDi19A,通过花序侵染法转化拟南芥,用T3代拟南芥进行耐冷性鉴定,分析低温处理对转基因拟南芥的根长、鲜重和存活率的影响。检测转TaDi19A拟南芥中抗逆相关基因表达变化,分析TaDi19A调控植物耐冷性的作用机制。构建诱饵载体pGBKT7-TaDi19A,验证自激活活性;利用酵母双杂交技术,将诱饵载体pGBKT7-TaDi19A和小麦cDNA文库共转化酵母AH109感受态细胞,通过SD/-Trp/-Leu/-His/-Ade和X-α-gal显蓝反应筛选得到阳性克隆,测序和BLAST分析获得候选蛋白。【结果】小麦TaDi19A编码区全长747 bp,编码248个氨基酸,分子量为28.03 kD,等电点为4.74,基因含4个外显子,3个内含子。TaDi19A蛋白靠近N-端包含锌指结合结构域,C端为Di19结构域,预测的TaDi19A蛋白三级结构包含2个α螺旋结构。磷酸化位点分析结果显示TaDi19A蛋白含有12个丝氨酸、9个苏氨酸和3个酪氨酸磷酸化位点。实时荧光定量PCR结果显示,TaDi19A受低温胁迫诱导表达。正常生长条件下,转基因和野生型拟南芥没有明显差异,低温处理下,转基因拟南芥的根长明显大于野生型拟南芥,并且耐冷性强于野生型拟南芥。下游基因检测结果表明,低温处理后,CBL1、CBL2和KIN1等冷胁迫响应相关基因在野生型和转基因植株中表达量都升高,在转基因植株中的表达量显著高于野生型,表明TaDi19A可能通过调节下游冷胁迫响应相关基因的表达提高转基因植物的耐冷性。通过对酵母双杂交系统筛选到的候选互作蛋白进行初步分析表明,这些候选互作蛋白主要参与植物体的信号转导和非生物胁迫响应过程,表明TaDi19A在植物的逆境信号转导及非生物胁迫响应过程中发挥着重要作用。【结论】小麦TaDi19A受低温诱导表达,过表达能够提高转基因拟南芥的耐冷性;而TaDi19A功能的发挥可能需要其他蛋白的参与。

关键词: 普通小麦, 锌指转录因子, 耐冷性, 酵母双杂交, 蛋白互作

Abstract: 【Objective】Zinc-finger transcription factors play an important role in stress signal transduction and abiotic stress response in plants. In this study, the function of TaDi19A was identified under low temperature stress and its interacting proteins were screened by yeast two-hybrid system to explore the regulation mechanism of TaDi19A.【Method】TaDi19A gene was isolated from the cold-treated wheat transcriptome profile. Bioinformatics method was used to analyze the molecular properties of the TaDi19A gene, SMART online tools were used for protein structure analysis; GSDS and PHYRE2 online tools were used to analyze gene structure and tertiary structure of TaDi19A protein; NetPhos 2.0 Server database was used to predict phosphorylation sites of TaDi19A protein. The quantitative real-time PCR (qRT-PCR), conducted using the cold-treated wheat cDNA based on SYBR Green technology, was used to analyze the expression pattern of TaDi19A under cold temperature stress treatment in different time periods. TaDi19A was fused with PBI121 to transform into wild-type (WT) Arabidopsis plants (Columbia-0) mediated by the floral dip method, homozygous T3 seeds of transgenic lines and WT were used for cold tolerance analysis which the root length, fresh weight, and survival rate were measured before and after cold treatment. The expressions of four stress-response genes were investigated in transgenic lines and WT under normal and low temperature conditions to analyze the cold-resistant regulation mechanism of TaDi19A. Bait plasmid pGBKT7-TaDi19A was constructed and the self-activation was detected. The pGBKT7-TaDi19A and wheat cDNA library was co-transformed into yeast cell AH109 by two-hybrid system, and the positive clones were screened via SD/-Trp/-Leu/-His/-Ade and SD/-Trp/-Leu/-His/-Ade /X-α-gal plate and these single clones were sequenced and analyzed by BLAST to obtain the interaction candidate proteins.【Result】The full length of TaDi19A gene was 747 bp with 4 exons, encoding 248 amino acids, and the protein molecular weight and isoelectric point of were 28.03 kDa and 4.74, respectively. TaDi19A protein included Zinc-finger binding domain, Di19 domain and the predicted tertiary structure contained 2 alpha helix. Phosphorylation site analysis showed that there were 12 serine, 9 threonine, and 3 tyrosine phosphorylation sites in TaDi19A protein. qRT-PCR analysis showed that TaDi19A was induced by low temperature. The root length and cold tolerance assays revealed that TaDi19A transgenic Arabidopsis increased the cold tolerance. The expression of several cold-stress-responsive genes was monitored through PCR analysis, the expression of genes CBL1, CBL2, CBL3 and KIN1 showed elevated levels in both WT and transgenic Arabidopsis plants under cold-stress condition, and the expression levels in transgenic plants were significantly higher than those in WT. Analysis of candidate proteins screened by yeast two-hybrid system revealed that those proteins mainly affected the signal transduction and abiotic stress response, which demonstrated that TaDi19A is critical to stress signal transduction and abiotic stress response in plants. 【Conclusion】Cold-inducible TaDi19A improved cold tolerance in transgenic Arabidopsis; TaDi19A might work via interacting with other proteins.

Key words: Triticum aestivum, zinc-finger transcription factor, cold tolerance, yeast two-hybrid, protein interaction