Engineering false smut resistance rice via host-induced gene silencing of two chitin synthase genes of Ustilaginoidea virens.

Abstract

Rice false smut (RFS), caused by the pathogenic ascomycete fungus Ustilaginoidea virens (U. virens), is one of the severely devastating diseases worldwide (Sun et al., 2020; Zhang et al., 2014). U. virens infects rice flowers causing over 25% yield loss, also producing poisonous mycotoxins that threaten the health of humans and animals (Fan et al., 2016; Zhang et al., 2014). So far, rice varieties showing resistance to RFS are rarely mined and none resistant genes are genetically confirmed (Zhang et al., 2019). Host-induced gene silencing (HIGS) is a powerful strategy to control diseases, where small interference RNAs (siRNAs) are produced by plants to silence essential genes of pathogens. Application of HIGS to control fungal diseases is successfully reported in several crops (Hou and Ma, 2020). Here, we evaluated the potential of HIGS for engineering rice against RFS by silencing chitin synthase genes of U. virens.