An overview of the virulence factors and the biocontrol potential of Sarocladium oryzae

Sarocladium oryzae is a filamentous fungus, commonly related to sheath rot, a disease until recently considered of low relevance but whose frequency has increased worldwide in rice cultivation. Few research groups have studied this microorganism, and consequently, the knowledge concerning biochemical and genetic factors that differentiate isolates within populations in terms of virulence (virulence factors/phytotoxin production) is limited. Some works have demonstrated that avirulent isolates of S. oryzae may act as biological control agents (BCAs), primarily due to their high potential for production of the secondary metabolite cerulenin, a potent antifungal. For these reasons, the goal of this paper is to review what is known about the virulence factors of S. oryzae, to highlight the main secondary metabolites produced by the fungus and their role in sheath rot development, and to try to establish a relationship between virulent, avirulent and potential BCA strains of S. oryzae.