RNA interference mediated disease resistance in vegetable crops: fundamental discovery to current trends

Vegetable productivity has been decreasing due to a range of stresses, both biotic and abiotic. Biotic factors mainly arise from nematodes, bacteria, viruses and fungal diseases. Traditional approaches such as chemical treatments and conventional breeding are often limited by environmental concerns and restricted genetic resources. Therefore, RNA interference (RNAi) has demonstrated significant promise as a molecular strategy for combating biotic stresses in vegetable crops, offering precision and sustainability in managing plant diseases. RNAi utilizes double-stranded RNA (dsRNA) to silence target genes through post-transcriptional gene silencing mechanisms, thereby interfering mRNA translation and protein synthesis. This gene-silencing mechanism, initiated by Dicer-like protein and facilitated by the RNA-induced silencing complex (RISC), involves small interfering RNAs (siRNAs), microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) to mediate specific gene knockdown. Advances in delivery methods, including host-induced gene silencing (HIGS), spray-induced gene silencing (SIGS) and virus-induced gene silencing (VIGS) have enabled effective application of RNAi in non-transgenic vegetable systems. Innovative tools such as BioClay and liposomal nanoparticles further improve efficacy and resilience of dsRNA applications in the field. This mechanism has been successfully employed to develop resistant cultivars and suppress plant pathogens such as fungi, viruses and nematodes. Notably, VIGS allows rapid gene function without the need for stable transformation. The versatility of RNAi platforms holds significant potential for improving disease resistance, particularly in vegetable crops that are vulnerable to diverse biotic stresses. This review underscores molecular mechanisms of RNAi, application through various delivery strategies and its growing relevance as an eco-friendly and adaptable tool to enhance vegetable production.