Open AccessDurable broad‐spectrum powdery mildew resistance in pea er1 plants is conferred by natural loss‐of‐function mutations in PsMLO1
Author(s) -
HUMPHRY MATT,
REINSTÄDLER ANJA,
IVANOV SERGEY,
BISSELING TON,
PANSTRUGA RALPH
Publication year - 2011
Publication title -
molecular plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.945
H-Index - 103
eISSN - 1364-3703
pISSN - 1464-6722
DOI - 10.1111/j.1364-3703.2011.00718.x
Subject(s) - powdery mildew , biology , medicago truncatula , blumeria graminis , lotus japonicus , pisum , plant disease resistance , sativum , botany , genetics , gene , symbiosis , bacteria , mutant
SUMMARY Loss‐of‐function alleles of plant‐specific MLO (M ildew Resistance L ocus O) genes confer broad‐spectrum powdery mildew resistance in monocot (barley) and dicot ( Arabidopsis thaliana , tomato) plants. Recessively inherited powdery mildew resistance in pea ( Pisum sativum ) er1 plants is, in many aspects, reminiscent of mlo ‐conditioned powdery mildew immunity, yet the underlying gene has remained elusive to date. We used a polymerase chain reaction (PCR)‐based approach to amplify a candidate MLO cDNA from wild‐type ( Er1 ) pea. Sequence analysis of the PsMLO1 candidate gene in two natural er1 accessions from Asia and two er1 ‐containing pea cultivars with a New World origin revealed, in each case, detrimental nucleotide polymorphisms in PsMLO1 , suggesting that PsMLO1 is Er1 . We corroborated this hypothesis by restoration of susceptibility on transient expression of PsMLO1 in the leaves of two resistant er1 accessions. Orthologous legume MLO genes from Medicago truncatula and Lotus japonicus likewise complemented the er1 phenotype. All tested er1 genotypes showed unaltered colonization with the arbuscular mycorrhizal fungus, Glomus intraradices , and with nitrogen‐fixing rhizobial bacteria. Our data demonstrate that PsMLO1 is Er1 and that the loss of PsMLO1 function conditions durable broad‐spectrum powdery mildew resistance in pea.