李泽 梁颖博 段佳琪 曾洪梅 李广悦 赵国存 杨秀芬

摘要 ：诱导抗病性是实现植物病害绿色防控的重要途径，大丽轮枝菌蛋白激发子PevD1能激活植物免疫系统，提高本生烟对烟草花叶病毒（TMV）和烟草野火病病原菌Pseudomonas syringae pv. tabaci、棉花对大丽轮枝菌Verticillium dahliae的抗病性，但分子机制不清晰。前期转录组测序（RNASeq）分析结果显示，本生烟响应PevD1诱导的差异表达基因显著富集在倍半萜烯和三萜烯的合成途径中。本文进一步分析了这些差异表达基因的功能，并通过测定倍半萜植保素辣椒醇合成关键基因EAS 和 EAH的转录表达水平和辣椒醇积累量，证明PevD1能诱导本生烟产生植保素辣椒醇，明确了PevD1诱导植保素辣椒醇的产生是提高植物抗病性的重要机制之一。

关键词 ：蛋白激发子PevD1; 转录组测序; 植保素; 辣椒醇

中图分类号： S 432.2

文献标识码： A

DOI： 10.16688/j.zwbh.2019605

Elicitor PevD1 induces phytoalexin capsidiol production and accumulation in Nicotiana benthamiana

LI Ze1， LIANG Yingbo1， DUAN Jiaqi1， ZENG Hongmei1， LI Guangyue1， ZHAO Guocun2， YANG Xiufen1*

（1. State Key Laboratory for Biology of Plant Diseases and Insect Pests， Institute of Plant Protection，

Chinese Academy of Agricultural Sciences， Beijing 100193， China; 2. Hebei Provincial

Pesticide Testing and Monitoring Station， Shijiazhuang 050031， China）

Abstract ：Induced disease resistance is an important approach for plant disease management. The Verticillium dahliae protein elicitor PevD1 could trigger plant immune response and improved the disease resistance of tobacco to Tobacco mosaic virus （TMV） and Pseudomonas syringae pv. tabaci， and the resistance of cotton to V.dahliae. However， the molecular mechanism is still unclear. In previous research， the differential expression genes （DEGs） in response to PevD1 in Nicotiana benthamiana were obtained by RNAseq and a lot of DEGs were significantly enriched in the sesquiterpene and triterpene synthesis pathway. In this study， we analyzed the functions of these DEGs in sesquiterpene and triterpene synthesis， and confirmed the transcriptional expression level of the key genes in the sesquiterpene synthesis pathway after PevD1 inducement. The results showed that the expression level of the key genes， EAS and EAH in capsidiol synthesis were significantly elevated. The capsidiol content also increased after PevD1 inducement. Our results indicated that PevD1induced capsidiol production is one of the important mechanism of plant disease resistance improvement.

Key words ：protein elicitor PevD1; RNASeq; phytoalexin; capsidiol

在长期进化过程中，植物为了抵御有害生物侵袭已经形成了精细而复杂的免疫防御系统，包括病原物/微生物相关分子模式（pathogen/microbeassociated molecular pattern， P/MAMP）诱导的PTI（PAMPtriggered immunity）和效应子诱导的ETI（effectortriggered immunity）[12]。当植物受到病原菌侵染或病原菌产生的激发子诱导后可以启动多重免疫防御反应，主要包括活性氧（ROS）暴发、NO积累、细胞膜通透性改变、病程相关蛋白表达、植物激素积累以及植保素的产生等，使植物产生局部抗性和系统抗性。利用植物诱导抗性提高植物自身免疫力、减轻病害发生已经成为现代植物保护的新技术。植保素是植物受到外界因素诱导产生的小分子植物次生代谢产物，能抑制或杀死多种植物病原微生物，常常被用作植物抗病性的分子标志[3]，在植物免疫防御系统中发挥着重要作用，其化学合成速度及积累量与植物抗病性密切正相关，被誉为植物的“化学武器”。……