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The coat protein of potato virus X is a strain‐specific elicitor of Rx 1‐mediated virus resistance in potato
Author(s) -
Bendahmane Abdelhafid,
Köhm Bärbel A.,
Dedi Cynthia,
Baulcombe David C.
Publication year - 1995
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1995.8060933.x
Subject(s) - potato virus x , tobacco mosaic virus , protoplast , biology , potexvirus , virology , virus , gene , rna , elicitor , microbiology and biotechnology , coat protein , potato virus y , inoculation , plant virus , genetics , horticulture
Summary The Rx 1 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 ( Rx 1 genotype) and Maris Bard ( rx 1 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 ( Rx 1 genotype) protoplasts to the same extent as PVX. The Rx 1 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 Rx 1‐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 non‐virion form of the coat protein.