State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China.
Plant Physiol. 2022 Sep 28;190(2):1418-1439. doi: 10.1093/plphys/kiac326.
Wheat stripe rust and powdery mildew are important worldwide diseases of wheat (Triticum aestivum). The wheat cultivar Xingmin318 (XM318) is resistant to both wheat stripe rust and powdery mildew, which are caused by Puccinia striiformis f. sp. tritici (Pst) and Blumeria graminis f. sp. tritici (Bgt), respectively. To explore the difference between wheat defense response against Pst and Bgt, quantitative proteomic analyses of XM318 inoculated with either Pst or Bgt were performed using tandem mass tags technology. A total of 741 proteins were identified as differentially accumulated proteins (DAPs). Bioinformatics analyses indicated that some functional categories, including antioxidant activity and immune system process, exhibited obvious differences between Pst and Bgt infections. Intriguingly, only 42 DAPs responded to both Pst and Bgt infections. Twelve DAPs were randomly selected for reverse transcription quantitative polymerase chain reaction (RT-qPCR) analysis, and the mRNA expression levels of 11 were consistent with their protein expression. Furthermore, gene silencing using the virus-induced gene silencing system indicated that glutathione S-transferase (TaGSTU6) has an important role in resistance to Bgt but not to Pst. TaGSTU6 interacted with the cystathionine beta-synthase (CBS) domain-containing protein (TaCBSX3) in both Pst and Bgt infections. Knockdown of TaCBSX3 expression only reduced wheat resistance to Bgt infection. Overexpression of TaGSTU6 and TaCBSX3 in Arabidopsis (Arabidopsis thaliana) promoted plant resistance to Pseudomonas syringae pv. Tomato DC3000. Our results indicate that TaGSTU6 interaction with TaCBSX3 only confers wheat resistance to Bgt, suggesting that wheat has different response mechanisms to Pst and Bgt stress.
小麦条锈病和白粉病是全球范围内影响小麦（Triticum aestivum）的重要病害。小麦品种兴民 318（XM318）对小麦条锈病和白粉病均具有抗性，这两种病害分别由条形柄锈菌（Puccinia striiformis f. sp. tritici，Pst）和禾本科布氏白粉菌（Blumeria graminis f. sp. tritici，Bgt）引起。为了探究小麦对 Pst 和 Bgt 防御反应的差异，我们采用串联质量标签（tandem mass tags，TMT）技术对 XM318 接种 Pst 或 Bgt 后的蛋白质进行了定量蛋白质组学分析。共鉴定到 741 个差异积累蛋白（differentially accumulated proteins，DAPs）。生物信息学分析表明，一些功能类别，包括抗氧化活性和免疫系统过程，在 Pst 和 Bgt 感染之间存在明显差异。有趣的是，只有 42 个 DAPs 对 Pst 和 Bgt 感染均有响应。随机选择 12 个 DAPs 进行反转录定量聚合酶链式反应（reverse transcription quantitative polymerase chain reaction，RT-qPCR）分析，其中 11 个的 mRNA 表达水平与其蛋白表达水平一致。此外，利用病毒诱导的基因沉默（virus-induced gene silencing，VIGS）系统进行基因沉默表明，谷胱甘肽 S-转移酶（glutathione S-transferase，GST）基因 TaGSTU6 对 Bgt 具有重要作用，但对 Pst 没有作用。在 Pst 和 Bgt 感染中，TaGSTU6 与半胱氨酸β-合酶（cystathionine beta-synthase，CBS）结构域蛋白（TaCBSX3）相互作用。敲低 TaCBSX3 的表达仅降低了小麦对 Bgt 感染的抗性。在拟南芥（Arabidopsis thaliana）中过表达 TaGSTU6 和 TaCBSX3 促进了植物对丁香假单胞菌番茄致病变种（Pseudomonas syringae pv. Tomato DC3000）的抗性。我们的结果表明，TaGSTU6 与 TaCBSX3 的相互作用仅赋予小麦对 Bgt 的抗性，表明小麦对 Pst 和 Bgt 胁迫具有不同的响应机制。
