Evaluation of transcriptome and potential candidate genes for RNAi sistyms in pathogenic fungi of citrus

Abstract

Brazil is responsible for a third of world production of orange, as well as for 80% of international orange juice market. The European Union is the main market in this Brazilian agrobusiness. However, losses in the export of fruits occur because of A1 quarantine diseases, causing restrictions on the importation of Brazilian citrus products into European countries. One of these diseases is the Citrus Black Spot caused by the fungus Phyllosticta citricarpa (Guignardia citricarpa). Serious losses in citrus fruit production are also caused by the fungus Colletotrichum acutatum, responsible for postbloom fruit drop citrus disease. Many works are being developed to study and control these phytopathogenic fungi. A currently and promising approach is the study of the gene expression by knockout or knockdown, using interference RNA (iRNA). Such sequences can be found by transcriptome analysis or by silencing of gene involved in phenotypic characteristics, due a insertion of exogenous DNA fragment in expressed region in the genome of the interested organism. Thereby, iRNA tools are very important to support the study of disease mechanisms used by phytopathogens fungi. Therewith, the goals of this work are to investigate the iRNA machinery in the transcriptome of P. citricarpa e C. acutatum; as well as, to make a library of random pathogenicity transformants; and to develop and validate a transformation system to evaluate the expression of candidate genes to iRNA studies in both fungi.