Identificação e caracterização molecular de efetores do tipo CRN (Crinkling and necrosis-inducing protein) de phytophthora nicotianae de citros.

Abstract

Phytophthora nícotíanae var. parasítíca is an oomiceto causal agente of gummosis (or foot rot) in citrus plants, one of most important diseases affecting the Brazilien Citriculture. Pathogens from this genus, including P. parasitíca, secrete typical effector molecules to establish an interaction with the host plant, moduling the defense response by either enabling the parasitism or activating the resistance mechanisms, leading to programmed cellular death

(PDC). Among these, cytoplasm effectors such as crinkler (CRN, _Çrínklíng Necrosís- Inducíng and Protein) possessing predicted secretion signals and conserved N-terminal

sequence motifs cause leaf crinkling and PDC phenotypes. The understanding of structure and functions of pathogen effectors as well loses caused by them in plants will to contribute to novel strategies for manipulation of plants, leading to resistance to oomicete pathogens. ln this context, the main objective of this work was to identify and to characterize CRN—like effectors from P. parasitíca, by using Bioinformatic tools to search within the CitEST/PP database expressed sequences induced by the in vitro growth, after 40 subculture cycles, and citrus— P. parasitíca interaction. As results, six ESTs encoding putative CRN-like effectors in P. parasitica were selected from CitEST/PP database. These ESTs were grouped into two contigs and two singlets, which share high amino acid sequences similarity with CRN genes from Phytophthora ínfestans. This is the first report on characterization of CRN-like genes of P. parasitíca. The four genes were found induced by the citrus interaction. Besides of genes

showed partial sequences, the amino acid deduced sequences from them possess conserved N- termini and diverse C—terminal that are different of others described at the present. The

studied putative CRN-like effectors may be part of P. parasitíca secretome and future works will be contribute to cloning, complete characterization of the CRN-like gene structures and functional roles.