ABSTRACT
Destruction of crop plants due to fungal pathogens is extremely, threatening food security. Managing the existing fungal diseases in plants has been a herculean task, with more impediments introduced because of the emerging mutant strains and climate change. Conventional chemical fungicides were used to control fungal diseases in plants. However, these fungicides are toxic and pose great risks to human health and the environment. Moreover, the emergence of novel fungicide-resistant strains due to inappropriate use of fungicides has crippled the chemical fungicide industry. Biofungicides (bacteria, fungi, actinomycetes and/or their products) offer a safe and effective platform for reducing disease impacts but are unable to eradicate the disease. RNA interference (RNAi) is a natural antiviral defense mechanism in plants which has been demonstrated as a potential defense strategy even against fungi, insects, nematodes and parasitic plants. Host plants are engineered to produce double-stranded RNAs (dsRNAs) or small-inhibiting RNAs (siRNAs) that find entry into the fungal pathogen during colonization and target vital genes by post-transcriptional gene silencing mechanism. Spray-Induced Gene Silencing (SIGS) involves the exogenous application of dsRNAs or siRNAs targeting unique pathogen genes and is an innovative plant protection strategy. Due to its sequence-specific targeting and environmentally clean identity, RNAi technology is the most sustainable plant disease management method.
