title: Carboxin-resistant mutant of ustilago maydis is impaired in its pathogenicity for zea mays
abstract: We analyzed the pathogenicity of chitin synthetase (chs) disruptants of Ustilago maydis obtained with the carboxin-resistant or the hygromycin-resistant cassettes. We found that only chitin synthetase (chs) mutants obtained by gene disruption with the carboxin resistance cassette lost their virulence to maize (Zea mays) seedlings. Carboxin is a systemic fungicide that inhibits respiration by preventing the oxidation of succinate. We demonstrated that carboxin-resistant transformants were affected in the levels of succinate dehydrogenase and respiratory activities when compared with hygromycin-resistant disruptants. We propose that loss of virulence in the carboxin-resistant transformants is owing to loss of respiratory fitness, which probably represents an important component of virulence in this fungus.http://link. springer-ny.com/link/service/journals/00284/bibs/39n5p291.html</HEA
authors.affiliation: Departamento de Ingenieria Genetica, Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional, Unidad Irapuato, Apartado Postal 629, 36500 Irapuato, Gto. Mexico.
authors.initials: J
authors.lastname: Ruiz-Herrera
authors.initials: AD
authors.lastname: Martinez-Espinoza
authors.initials: PE
authors.lastname: Alvarez
authors.initials: B
authors.lastname: Xoconostle-Cazares