TaWRKY45转录因子在小麦高温抗条锈病中的功能研究

发布时间：2018-03-13 22:20

本文选题：小偃6号　切入点：高温抗病性　出处：《西北农林科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：由条形柄锈菌(Puccinia striiformis f.sp.tritici,Pst)引发的小麦条锈病是一种世界性病害。它通过气流远距离传播,严重威胁着小麦的生产安全,造成了巨大的经济损失。小麦抗病品种往往由于条锈菌生理小种毒性的变异而丧失抗病性。因此,选育非小种专化性、抗病持久的小麦品种是解决条锈菌危害的有效方法。小偃6号是一种全生育期高温抗条锈性的小麦品种,能在较高温度诱导下产生低反应型抗病性,且具有非小种专化性和持久抗病性特征。WRKY转录因子在小麦抗条锈病中起着重要的作用,其中TaWRKY45转录因子在小麦抗赤霉病、叶锈病、白粉病等过程起着正向调控的作用,但其在小麦高温抗条锈病中的作用尚未报道。本研究以小偃6号小麦品种和条锈菌CYR32生理小种为试验材料,克隆了TaWRKY45基因,通过实时荧光定量PCR技术(Real-time quantitative PCR,qRT-PCR)研究了TaWRKY45的表达模式,并利用病毒诱导的基因沉默(VIGS)技术,研究了TaWRKY45沉默后对小偃6号高温抗条锈病的影响。取得了以下主要结果:1.克隆得到TaWRKY45基因。该序列大小为1234 bp,具有完整的开放阅读框(ORF),编码293个氨基酸。蛋白结构域分析显示,TaWRKY45在N端含有一个保守的WRKYGQK,在C端含有一个C2-HC型的锌指结构。序列比对结果显示TaWRKY45与水稻OsWRKY45蛋白亲缘关系最近,支持率达到99%。2.TaWRKY45在小偃6号根、茎、叶中均有表达,且根中的表达量显著高于茎、叶中的表达量。水杨酸(SA)处理和接菌后经高温处理均可诱导TaWRKY45上调表达。3.TaWRKY45在小偃6号高温抗条锈病进程中起着正向调控作用。TaWRKY45基因沉默后,其表达量下降了50%~70%。接种条锈菌后第8天,经高温处理,TaWRKY45基因沉默的叶片上夏孢子堆数目增多,单个侵染点的条锈菌线性长度和夏孢子堆线性长度增加,叶片坏死细胞数量减少,植株抗病能力减弱。
[Abstract]:Wheat stripe rust caused by Puccinia striiformis f.sp.triticizer is a worldwide disease. The disease resistance of wheat varieties is often lost because of the variation of the toxicity of physiological races of stripe rust. Xiaoyan 6 is a wheat variety with high temperature resistance to stripe rust in the whole growth period, which can produce low response disease resistance under high temperature induction. WRKY transcription factors play an important role in wheat stripe rust resistance, and TaWRKY45 transcription factors play a positive role in wheat resistance to scab, leaf rust and powdery mildew. However, its role in wheat high temperature resistance to stripe rust has not been reported. In this study, the TaWRKY45 gene was cloned from wheat variety Xiaoyan 6 and CYR32 physiological race of stripe rust. The expression pattern of TaWRKY45 was studied by real-time quantitative PCR qRT-PCR, and virus induced gene silencing was used to detect the expression of TaWRKY45. The effect of TaWRKY45 silencing on the resistance of Xiaoyan 6 to high temperature stripe rust was studied. The following main results were obtained: 1: 1. The TaWRKY45 gene was cloned. The sequence was 1234 BP, which had complete open reading frame ORF, encoding 293 amino acids. The structural analysis showed that TaWRKY45 contained a conserved WRKYGQK at the N-terminal and a zinc finger structure of C2-HC at the C-terminal. The sequence alignment results showed that TaWRKY45 was closely related to OsWRKY45 protein in rice. The approval rate reached 99.2.TaWRKY45 was expressed in root, stem and leaf of Xiaoyan 6, and the expression of TaWRKY45 in root was significantly higher than that in stem. Both salicylic acid treatment and high temperature treatment could induce the up-regulation of TaWRKY45 expression. 3. TaWRKY45 played a positive regulatory role in the process of high temperature resistance to stripe rust of Xiaoyan 6. After silencing, TaWRKY45 gene was silenced. On the 8th day after inoculation of stripe rust, the number of summer spores in leaves silenced by TaWRKY45 gene increased, the linear length of stripe rust and the linear length of summer spores increased, and the number of necrotic cells in leaves decreased. The disease resistance of plants was weakened.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S435.121.42

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