Expressão quantitativa dos genes efetores NPP1 e CBEL em Phytophora parasítica durante interação com folhas de citros.

Abstract

Phytophthora parasitica is able to infect ali parts of the citrus plants and affect ali stages of the production chain, from the nursery to the marketed product. This species secret effectors which modulate the plant responses, facilitating infection. In this study, the quantitative expression, temporal and comparative extracellular effector genes of P. parasitica was analyzed during citrus interaction, by using RT -qPCR. From R NAs isolated from pathogen structures (mycelium, sporangium, chlamydospores and zoospores) held only in water (non-inoculated, Nl) and inoculated (I) in pieces of sour orange leaves (Citrus aurantium) whitin water during times O, 1.5, 3, 6 and 12 hours after inoculation (h.a.i.), analysis of changes in expression of CBEL02 and NPP102 genes in P. parasitica revealed that the expression pattern was different between them, although they have been transcribed in both treatments and the studied time points. The NPP102 gene showed two maximum expression peaks, 1.5 and 6 h.a.i. in both treatments, with a expression levei higher in the I at 1.5 h.a.i. and in the Nl treatment at 6 h.a.i. Moreover, the gene CBEL02 achieved lower leveis of expression for both treatments at ali studied time points ranging from 0.3 times, in the I treatment, until 6.4

in Nl, an except for I at 12 h.a.i. The study of the effector gene expression during citrus- P. parasitica interaction may contribute to the understanding of pathogenicity

mechanisms of this pathogen, aiming at developing control alternatives.