State Key Laboratory of Grassland Agro-Ecosystems, School of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, PR China; Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 12, Zhongguancun South Street, Beijing 100081, PR China.
Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 12, Zhongguancun South Street, Beijing 100081, PR China.
Microbiol Res. 2014 May-Jun;169(5-6):476-82. doi: 10.1016/j.micres.2013.08.001. Epub 2013 Sep 27.
In our previous study, PevD1 was characterized as a novel protein elicitor produced by Verticillium dahliae inducing hypersensitive response (HR) and systemic acquired resistance (SAR) in tobacco plants; however, the detailed mechanisms of PevD1's elicitor activity remain unclear. In this study, five mutant fragments of PevD1 were generated by polymerase chain reaction-based mutagenesis and the truncated proteins expressed in Escherichia coli were used to test their elicitor activities. Biological activity analysis showed that the N-terminal and C-terminal of PevD1 had distinct influence on HR and SAR elicitation. Fragment PevD1ΔN98, which spans the C-terminal 57 amino acids of PevD1, was critical for the induction of HR in tobacco plants. In contrast, fragment PevD1ΔC57, the N-terminal of 98 amino acids of PevD1, retained the ability to induce SAR against tobacco mosaic virus (TMV) but not induction of HR, suggesting that the induction of HR is not essential for SAR mediated by PevD1. Our results indicated that fragment PevD1ΔC57 could be a candidate peptide for plant protection against pathogens without causing negative effects.
在我们之前的研究中，PevD1 被鉴定为一种由黄萎病菌产生的新型蛋白激发子，能诱导烟草植株产生过敏反应 (HR) 和系统获得性抗性 (SAR)；然而，PevD1 激发子活性的详细机制仍不清楚。在这项研究中，我们通过聚合酶链式反应（PCR）诱变生成了 PevD1 的五个突变片段，并在大肠杆菌中表达了这些截断蛋白，以测试它们的激发活性。生物活性分析表明，PevD1 的 N 端和 C 端对 HR 和 SAR 的诱导有明显的影响。跨越 PevD1 C 端 57 个氨基酸的 PevD1ΔN98 片段对烟草植株 HR 的诱导至关重要。相比之下，PevD1ΔC57 片段，即 PevD1 的 N 端 98 个氨基酸，保留了诱导烟草花叶病毒 (TMV) SAR 的能力，但不能诱导 HR，这表明 HR 的诱导对于 PevD1 介导的 SAR 并非必需。我们的研究结果表明，PevD1ΔC57 片段可能是一种候选肽，可用于植物防病而不产生负面影响。
