A genetic mechanism for emergence of races in Fusarium oxysporum f. sp. lycopersici: inactivation of avirulence gene AVR1 by transposon insertion.

ABSTRACT: Compatible/incompatible interactions between the tomato wilt fungus Fusarium oxysporum f. sp. lycopersici (FOL) and tomato Solanum lycopersicum are controlled by three avirulence genes (AVR1-3) in FOL and the corresponding resistance genes (I-I3) in tomato. The three known races (1, 2 and 3) of FOL carry AVR genes in different combinations. The current model to explain the proposed order of mutations in AVR genes is: i) FOL race 2 emerged from race 1 by losing the AVR1 and thus avoiding host resistance mediated by I (the resistance gene corresponding to AVR1), and ii) race 3 emerged when race 2 sustained a point mutation in AVR2, allowing it to evade I2-mediated resistance of the host. Here, an alternative mechanism of mutation of AVR genes was determined by analyses of a race 3 isolate, K

SUBMITTER: Inami K 

PROVIDER: S-EPMC3428301 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature