Induction of defense mechanisms in mycorrhized tomato plants against the attack of Oidiopsis taurica (Lev.) Salm

Abstract

In order to evaluate mycorrhized tomato plants against the attack of Oidiopsis taurica pathogen an experiment was conducted. Plants previously treated with arbuscular mycorrhizal fungus (AMF) Glomus cubense (40 spores g-1) and G. mosseae (60 spores g-1) were challenged with O. taurica (2 x 104 spores mL-1), at 21 days of germination. Several enzymatic activities related to the induction of defense (PRX, PPO, ? -1.3 glucanase, chitinase and phenylalanine ammonia lyase) were determined and mycorrhizal variables (visual density or fungal occupation (DV) and colonization rate) and percentage of damage caused by the pathogen were measured. Mycorrhizal species induced systemic responses in plants where higher levels of protection were observed in plants treated with G. cubense. These levels were not sufficient to prevent colonization of the pathogen and thus the damage caused by this, however, there was a differential response between both AMF studied. The low response induced by G. mosseae against the attack of the plant pathogenic fungus was remarkable, which leads to the conclusion that not all HMA have the same inductive response against a specific plant pathogen.