Expression of genes of salicylic acid pathway in response to Candidatus Liberibacter spp. infection, the causal agent of citrus Huanglongbing

Abstract

Although the citrus industry in São Paulo has expressive participation in the Brazilian agribusiness, old and new diseases challenge the production activities. Among them the Huanglongbing (greening) is a most devasting disease in the world. There are no resistance source to support breeding programs, and the pathogenicity mechanism of the bacterium Ca. Liberibacter spp, restrict to the phloem sieves, is still completely unknown. Previous studies in our group on transcriptome (RNA-seq and microarray)of infected tissue, have demonstrated an active response to the infection of bacteria.Several genes involved in known pathways of plant-pathogen interactions were identified. But there is no clear evidence which ones are really involved in the response. Our goals will be to evaluate by real time quantitative PCR (RT-qPCR)genes of salicylic acid (SA) pathway, usually associated to biotrophic pathogens,as well as some downstream of this pathway. Both susceptible (sweet orange) and tolerant genotype (Poncirus trifoliata) will be evaluated. (AU)