Evaluation of Toxins interaction Phyllosticta citricicarpa and sweet orange (Citrus sinensis (L.) Osb.)

Abstract

Citrus industry is one of the main activities of the agribusiness world. Brazil is the largest citrus producer. However, this sector faces some problems. Among the diseases affecting the citrus culture, is the Citrus Black Spot (CBP), caused by the fungus Phyllosticta citricarpa. The disease affects all Citrus species with the exception of sour orange and lemon trees and their hybrids. In the host-pathogen interactions, plants use structural mechanisms or biochemical in defending themselves against pathogens, which use chemicals and proteins to attack the host. Among these components use to pathogens to cause disease are secondary metabolites, such as toxins. The synthesis of toxins is important for many pathogenic fungi, particularly the necrotrophics ones, considered as effectors of these fungi. Effector proteins are released or associated with an organism that change the physiology of another organism. Transporters are also important for the pathogenicity, once they move substances aiding the secretion of the toxin. With the sequencing of the genome of P. citricarpa by our research group, genes have been identified that are likely involved in the synthesis and transport of toxins. Thus, the aim of this study is to evaluate the differential expression of these genes when they interact with citrus. It is expected that the results indicate the importance of toxins in this fungus pathogenic mechanism and the establishment of the disease on plants.