Disruption of virus movement confers broad-spectrum resistance against systemic infection by plant viruses with a triple gene block

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 91; no. 22; pp. 10310 - 10314
• Main Authors: Beck, D.L. (The Horticultural and Food Research Institute of New Zealand, Auckland, New Zealand), Van Dolleweerd, C.J, Lough, T.J, Balmori, E, Voot, D.M, Andersen, M.T, O'Brien, I.E.W, Forster, R.L.S
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 25.10.1994; National Acad Sciences; National Academy of Sciences
• Subjects: Base Sequence; CARLAVIRUS; Cloning, Molecular; Conserved Sequence; Disease Susceptibility; DNA Primers; Flowers & plants; GENE; GENES; Genes, Viral; Genetic engineering; GENETICA; Genetics; GENETIQUE; Infections; Inoculation; Kinetics; Leaves; Molecular Sequence Data; MUTACION INDUCIDA; Mutagenesis; MUTATION PROVOQUEE; NICOTIANA; Open Reading Frames; PATHOGENESE; PATOGENESIS; Plant Leaves - virology; Plants; Plants - virology; Plants, Genetically Modified; Polymerase Chain Reaction; POTEXVIRUS; Potexvirus - genetics; Potexvirus - physiology; POTEXVIRUS X DE LA PATATA; POTEXVIRUS X POMME DE TERRE; PROTEINAS; PROTEINE; RESISTANCE AUX MALADIES; Resistance movements; RESISTENCIA A LA ENFERMEDAD; Restriction Mapping; RNA; RNA, Viral - biosynthesis; Templates, Genetic; TRANSFERENCIA DE GENES; TRANSFERT DE GENE; Transgenic plants; Viral Proteins - biosynthesis; Viral Proteins - genetics; Virions; VIRUS; VIRUS DE LAS PLANTAS; VIRUS DES VEGETAUX; Viruses; white clover mosaic virus
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.91.22.10310

White clover mosaic virus strain O (WClMV-O), species of the Potexvirus genus, contains a set of three partially overlapping genes (the triple gene block) that encodes nonvirion proteins of 26 kDa, 13 kDa, and 7 kDa. These proteins are necessary for cell-to-cell movement in plants but not for replication. The WClMV-O 13-kDa gene was mutated (to 13* ) in a region of the gene that is conserved in all viruses known to possess triple-gene-block proteins. All 10 13* transgenic lines of Nicotiana benthamiana designed to express the mutated movement protein were shown to be resistant to systemic infection by WClMV-O at 1 microgram of WClMV virions per ml, whereas all plants from susceptible control lines became systemically infected. Of the 13* transgenic lines, 3 selected for their abundant seed supply were shown to be resistant to systemic infection when challenged by inoculation with three different WClMV strains (O, M, and J) or with WClMV-O RNA at 10 micrograms/ml. Most plants were also resistant to systemic infection at inoculum concentrations up to 250 micrograms of WClMV virions per ml. In addition, the three 13* transgenic plant lines were found to be resistant to systemic infection with two other members of the Potexvirus group, potato virus X and narcissus mosaic virus, and the Carlavirus potato virus S but not to be resistant to tobacco mosaic virus of the Tobamovirus group. These results indicate that virus resistance can be engineered into transgenic plants by expression of dominant negative mutant forms of triple-gene-block movement proteins