Jenner Carol E, Wang Xiaowu, Tomimura Kenta, Ohshima Kazusato, Ponz Fernando, Walsh John A
Horticulture Research International, Wellesbourne, Warwick, CV35 9EF, UK.
Mol Plant Microbe Interact. 2003 Sep;16(9):777-84. doi: 10.1094/MPMI.2003.16.9.777.
Two isolates of the potyvirus Turnip mosaic virus (TuMV), UK 1 and CDN 1, differ both in their general symptoms on the susceptible propagation host Brassica juncea and in their ability to infect B. napus lines possessing a variety of dominant resistance genes. The isolate CDN 1 produces a more extreme mosaic in infected brassica leaves than UK 1 and is able to overcome the resistance genes TuRB01, TuRB04, and TuRB05. The resistance gene TuRB03, in the B. napus line 22S, is effective against CDN 1 but not UK 1. The nucleic acid sequences of the UK 1 and CDN 1 isolates were 90% identical. The C-terminal half of the P3 protein was identified as being responsible for the differences in symptoms in B. juncea. A single amino acid in the P3 protein was found to be the avirulence determinant for TuRB03. Previous work already has identified the P3 as an avirulence determinant for TuRB04. Our results increase the understanding of the basis of plant-virus recognition, show the importance of the potyviral P3 gene as a symptom determinant, and provide a role in planta for the poorly understood P3 protein in a normal infection cycle.
芜菁花叶病毒（TuMV）的两个分离株，UK 1和CDN 1，在其对易感繁殖寄主芥菜上的一般症状以及感染具有多种显性抗性基因的甘蓝型油菜品系的能力方面均存在差异。分离株CDN 1在感染的芸苔属叶片中产生的花叶病症状比UK 1更严重，并且能够克服抗性基因TuRB01、TuRB04和TuRB05。甘蓝型油菜品系22S中的抗性基因TuRB03对CDN 1有效，但对UK 1无效。UK 1和CDN 1分离株的核酸序列有90%的同一性。P3蛋白的C端一半被确定是造成芥菜症状差异的原因。发现P3蛋白中的一个氨基酸是TuRB03的无毒决定子。先前的研究已经确定P3是TuRB04的无毒决定子。我们的研究结果增进了对植物-病毒识别基础的理解，表明了马铃薯Y病毒属P3基因作为症状决定子的重要性，并为正常感染周期中了解较少的P3蛋白在植物体内的作用提供了依据。
