title: Construction of near-isogenic lines to investigate the efficiency of different resistance genes to anthracnose.
abstract: A suitable experimental model was designed with the aim of investigating the specific effect of different resistance genes in the Phaseolus vulgaris - Colletotrichum lindemuthianum interaction. The four resistance genes examined were chosen because they confer a different phenotype (resistance or susceptibility) to the lines carrying them when challenged by a range of C. lindemuthianum races. These different resistance genes were introgressed independently into the same susceptible recipient line. The isogenicity of the five near-isogenic lines (NILs) thus obtained (four resistant lines, one susceptible line = recipient line) was assessed by a RAPD analysis. The hypersensitive reaction occurred at the same time after infection, whatever the resistance gene present, when the NILs were challenged by the avirulent race 9 of the pathogen. In contrast, the pathogen development was arrested more or less rapidly in the different NILs. At the first stages of the infection process, the transcripts encoding phenylalanine ammonia-lyase were accumulated to a different extent in the different resistant NILs but always to a higher level than in the susceptible recipient line. These results suggest that the different resistance genes operate through more than one way in the production of defense factors.
authors.affiliation: Biologie Moléculaire Végétale, URA CNRS 1128, IBP, Bât 630, Université Paris XI, 91405, Orsay, France.
authors.forename: A
authors.initials: A
authors.lastname: Mahé
authors.forename: H
authors.initials: H
authors.lastname: Bannerot
authors.forename: J
authors.initials: J
authors.lastname: Grisvard