马铃薯X病毒的外壳蛋白是马铃薯中Rx1介导的病毒抗性的菌株特异性激发子。

The coat protein of potato virus X is a strain-specific elicitor of Rx1-mediated virus resistance in potato.

作者信息

Bendahmane A, Köhn B A, Dedi C, Baulcombe D C

机构信息

Sainsbury Laboratory, Norwich Research Park, Colney, UK.

出版信息

Plant J. 1995 Dec;8(6):933-41. doi: 10.1046/j.1365-313x.1995.8060933.x.

DOI:10.1046/j.1365-313x.1995.8060933.x

PMID:8580963

Abstract

The Rx1 gene in potato confers extreme resistance to potato virus X (PVX). To investigate the mechanism and elicitation of Rx resistance, protoplasts of potato cv. Cara (Rx1 genotype) and Maris Bard (rx1 genotype) were inoculated with PVX and tobacco mosaic virus (TMV). At 24 h post-inoculation in Maris Bard protoplasts there was at least 100-fold more PVX RNA than in protoplasts of Cara. TMV RNA accumulated to the same level in both types of protoplast. However, when the TMV was inoculated together with PVX the accumulation of TMV RNA was suppressed in the Cara (Rx1 genotype) protoplasts to the same extent as PVX. The Rx1 resistance also suppressed accumulation of a recombinant TMV in which the coat protein gene was replaced with the coat protein gene of PVX. It is therefore concluded that Rx1-mediated resistance is elicited by the PVX coat protein, independently of any other proteins encoded by PVX. The domain of the coat protein with elicitor activity was localized by deletion and mutation analysis to the structural core of a nonvirion form of the coat protein.

摘要

马铃薯中的Rx1基因赋予对马铃薯X病毒（PVX）的极端抗性。为了研究Rx抗性的机制和诱导因素，用PVX和烟草花叶病毒（TMV）接种了马铃薯品种Cara（Rx1基因型）和Maris Bard（rx1基因型）的原生质体。接种后24小时，Maris Bard原生质体中的PVX RNA比Cara原生质体中的至少多100倍。TMV RNA在两种原生质体中的积累水平相同。然而，当TMV与PVX一起接种时，Cara（Rx1基因型）原生质体中TMV RNA的积累被抑制到与PVX相同的程度。Rx1抗性还抑制了一种重组TMV的积累，该重组TMV的外壳蛋白基因被PVX的外壳蛋白基因所取代。因此得出结论，Rx1介导的抗性是由PVX外壳蛋白引发的，与PVX编码的任何其他蛋白无关。通过缺失和突变分析将具有激发子活性的外壳蛋白结构域定位到外壳蛋白非病毒粒子形式的结构核心。