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Genetic dissection of a TIR ‐ NB ‐ LRR locus from the wild N orth A merican grapevine species M uscadinia rotundifolia identifies paralogous genes conferring resistance to major fungal and oomycete pathogens in cultivated grapevine
Author(s) -
Feechan Angela,
Anderson Claire,
Torregrosa Laurent,
Jermakow Angelica,
Mestre Pere,
WiedemannMerdinoglu Sabine,
Merdinoglu Didier,
Walker Amanda R.,
CadleDavidson Lance,
Reisch Bruce,
Aubourg Sebastien,
Bentahar Nadia,
Shrestha Bipna,
Bouquet Alain,
AdamBlondon AnneFrançoise,
Thomas Mark R.,
Dry Ian B.
Publication year - 2013
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 - 10.1111/tpj.12327
Subject(s) - downy mildew , plasmopara viticola , biology , oomycete , powdery mildew , locus (genetics) , plant disease resistance , botany , genetics , gene
Summary The most economically important diseases of grapevine cultivation worldwide are caused by the fungal pathogen powdery mildew ( E rysiphe necator syn. U ncinula necator ) and the oomycete pathogen downy mildew ( P lasmopara viticola ). Currently, grapegrowers rely heavily on the use of agrochemicals to minimize the potentially devastating impact of these pathogens on grape yield and quality. The wild N orth A merican grapevine species M uscadinia rotundifolia was recognized as early as 1889 to be resistant to both powdery and downy mildew. We have now mapped resistance to these two mildew pathogens in M . rotundifolia to a single locus on chromosome 12 that contains a family of seven TIR ‐ NB ‐ LRR genes. We further demonstrate that two highly homologous (86% amino acid identity) members of this gene family confer strong resistance to these unrelated pathogens following genetic transformation into susceptible V itis vinifera winegrape cultivars. These two genes, designated r esistance to U ncinula n ecator ( M r RUN 1 ) and r esistance to P lasmopara v iticola ( M r RPV 1 ) are the first resistance genes to be cloned from a grapevine species. Both M r RUN 1 and M r RPV 1 were found to confer resistance to multiple powdery and downy mildew isolates from F rance, N orth A merica and A ustralia; however, a single powdery mildew isolate collected from the south‐eastern region of N orth A merica, to which M . rotundifolia is native, was capable of breaking M r RUN 1 ‐mediated resistance. Comparisons of gene organization and coding sequences between M . rotundifolia and the cultivated grapevine V . vinifera at the M r RUN 1 / M r RPV 1 locus revealed a high level of synteny, suggesting that the TIR ‐ NB ‐ LRR genes at this locus share a common ancestor.