?Characterization of the defense responses of Prunus persica after Taphrina deformans inoculation

RIVERO, NERY; GOLDY; CAMILA; SVETAZ, LAURA; VALENTINI, GABRIEL; BUDDE, CLAUDIO OLAF; DRINCOVICH, MARÍA FABIANA; LARA, MARÍA VALERIA

Foz do Iguacú

Congreso; 11th International Congress of Plant Molecular Biology.; 2015

Peach Leaf Curl is a disease affecting leaves, buds, fruits and flowers of Prunus persica. Taphrina deformans (Berk.) is the biotrophic fungus causal of this disease. Orchards throughout the world are affected displaying decreases in yield and longevity. Resistance to this pathogen is rare; genotypes screenings have rendered none or few cultivars as tolerant. Our group has started the characterization of this plant-pathogen interaction by using a resistant and two susceptible genotypes. After inoculation with blastospores the filamentose phase of the fungus is developed in both susceptible and genotypes. Nevertheless, we have previously established that the metabolomic response differs in susceptible versus resistant genotypes. In order to explore the defense responses of P. persica against T. deformans we evaluated the expression levels of transcripts encoding five Pathogenesis Related (PR) proteins by real time quantitative qRT-PCR at different time points after T. deformans inoculation. In the three genotypes transcripts encoding a Phenylalanine Ammonia-Lyase (PAL), Thaumatin like protein (TLP1) and PR 10 were induced after inoculation, while the relative levels of transcripts encoding a Lipid Transfer Protein (LTP1) were decreased. Changes varied depending on the genotype. On the other hand, no changes were observed in the relative levels of catalase. In addition, histochemical analyses revealed the production of superoxide anion in all genotypes, which was earlier in the resistant than in the susceptible genotypes. We are currently studying the participation of salicylic acid, jasmonic acid and ethylene in the defense response and trying to elucidate the bases of the resistance.