Open AccessXanthomonas axonopodis pv. glycines Soybean Cultivar Virulence Specificity Is Determined by avrBs3 Homolog avrXg1
Author(s) -
Dusit Athinuwat,
S. Prathuangwong,
Luciana Cursino,
Thomas J. Burr
Publication year - 2009
Publication title -
phytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.264
H-Index - 131
eISSN - 1943-7684
pISSN - 0031-949X
DOI - 10.1094/phyto-99-8-0996
Subject(s) - virulence , biology , cultivar , hypersensitive response , xanthomonas , pathogen , gene , race (biology) , genetics , plant disease resistance , microbiology and biotechnology , botany
Three races of Xanthomonas axonopodis pv. glycines were identified on pustule disease resistant and susceptible soybean cultivars based on virulence phenotype. For race 3, an avrBs3 homolog, avrXg1 was identified that conferred resistance expressed as a hypersensitive response on resistant cultivar Williams 82. Mutations in two predicted functional domains of avrXg1 resulted in gained virulence on Williams 82 and an increase in bacterial population number on susceptible cultivars. Expression of avrXg1 in race 1, that is predicted to confer a nonspecific HR, led to virulence on susceptible cultivars Spencer and PI 520733. Expression of avrXg1 in race 2, that is predicted of carrying avrBs3-like genes, resulted in gained virulence and fitness of pathogen on both resistant and susceptible cultivars. The results demonstrate multifunctions for avrXg1 dependent on pathogen and plant genetic backgrounds.