Effectoromics: effectors as a new tool to control Phytophthora parasitica, causal agent of citrus root rot and gummosis.

Abstract

Brazil is one of the top orange producers in the world. However, the producers struggle with a constant threat coming from pests and diseases, such as gummosis and root rot, both caused by the oomycete Phytophthora parasitica. It is well known that Phytophthora species secrete hundred of effector proteins that enable infection. Manipulating the effectors molecules can lead to pathogen loss of virulence and induce plant defenses. The mechanistic molecular functioning of effectors remains poorly understood, and almost nothing is described for phytophthora-citrus diseases. Thus, it is proposed here a detailed study focusing P. parasitica effectors in interaction with citrus plants. The main objectives of this project are: 1) identification of the general effectors candidates and the ones of the families RxLR and CRN effectors in the genome and transcriptome of P. parasitica, and 2) evaluate de expression of these genes prior and after infection in citrus, as well assymptoms and plant defense responses. The Project is divided in two phases. The first phase will focus on the identification of RxLR and CRN effectors in the genome of P. parasitica after applying a pipeline with bioinformatic tools and will evaluate the expression of the candidate genes after treatment with citrus root-extracts. At the second phase, the expression of general and RxLR and CRN effector genes will be analyzed during infection in citrus in parallel with physiological responses of plants and activation of genes related to defense. This project has the potential to originate valuable information todevelop more efficient strategies to control citrus diseases.