Virus-Induced Gene Silencing (VIGS) in Functional Genomics: Advances and Applications in Capsicum annuum L.

This article provides a comprehensive analysis of Virus-Induced Gene Silencing (VIGS), which is an effective tool for studying the functional genomics of organisms that are poorly amenable to genomic editing. The VIGS method is grounded in the plant’s post-transcriptional gene silencing (PTGS) machinery and utilizes recombinant viral vectors to trigger systemic suppression of endogenous plant gene expression, leading to visible phenotypic changes that enable gene function characterization. This article details the application of VIGS in model organisms (Arabidopsis thaliana, Nicotiana benthamiana) and a wide range of crops, with a special focus on the Solanaceae family, particularly pepper (Capsicum annuum L.). This review analyzes the design and structural elements of viral vectors used for VIGS, such as Tobacco Rattle Virus (TRV), Broad Bean Wilt Virus 2 (BBWV2), Cucumber Mosaic Virus (CMV), geminiviruses (CLCrV, ACMV), and satellite virus-based systems. It also critically examines the key factors that determine silencing efficiency. These factors encompass insert design, agroinfiltration methodology, plant developmental stage, agroinoculum concentration, plant genotype, and environmental factors (temperature, humidity, photoperiod). Particular attention is given to optimization strategies, such as the use of viral suppressors of RNA silencing (VSRs). This article concludes with the achievements in using VIGS to identify pepper genes governing fruit quality (color, biochemical composition, pungency), resistance to biotic (bacteria, oomycetes, insects) and abiotic (temperature, salt, osmotic stress) factors, as well as genes regulating plant architecture and development. The results obtained demonstrate the advantages and limitations of VIGS, alongside future perspectives for its integration with multi-omics technologies to accelerate breeding and advance functional genomics studies in pepper.