Understanding the virulence strategies of Penicillium digitatum against the host citrus

Abstract

Phytopathogens have developed a variety of specialized virulence strategies to facilitate colonization of plant tissue, and successful infect and modulate the host plant physiology, including the production of low-molecular-weight phytotoxins (secondary metabolites). Brazil is the world's largest producer of citrus, which are susceptible to a number of diseases that cause significant losses during the postharvest phase. The most common and serious diseases that affect citrus are green and blue molds caused, respectively, by Penicillium digitatum and Penicillium italicum. The actual research concerning such pathogens focuses on treatments against the infection symptoms. However, the molecular basis of infection and specificity towards the host remain largely unknown. In this sense, we aim to elucidate biologically active constituents of host-pathogen interaction and study them concerning functionality based on molecular biology and genetic studies. The idea is to perform knock out of key genes involved in the biosynthesis of active secondary metabolites allowing the production of a particular metabolite deficient mutants that will be studied concerning pathogenicity against citrus, providing insights into the chemical relationship between pathogen/host which could contribute to preliminary understanding of the strategies used by this Penicillium species to infect citrus. Understanding the production of phytotoxins in their biological context represents an important step to develop ways to protect citrus from fungal infections. (AU)