RNA interference: A promising approach for crop improvement

RNA interference (RNAi) is a naturally occurring biological process that regulates plant growth and development, defense against pathogens, and environmental stresses. It is a sequence-specific homology-based silencing mechanism in which the function of a gene is interfered or suppressed. Small interfering RNAs (siRNAs) and microRNAs (miRNAs) are produced inside the plant cell through the activation of RNAi machinery, which downregulates the expression of the target genes at transcriptional and translational levels. RNAi is more specific, precise in its action, and considered as a potential technology for functional genomics studies. In the last 15 years, it has emerged as a scientific breakthrough for crop improvement without affecting other agronomic traits. It has also been employed as a novel method in understanding the basic phenomenon of plant defense and metabolism. Several desirable traits have been improved in the crop varieties through RNAi, which include crop protection against biotic and abiotic stresses, enhancement of nutritional value, alteration in plant architecture for better adaptation to environmental conditions, overexpression or removal of secondary metabolites, enhancement of shelf life of fruits and vegetables, generation of male sterile lines, and development of seedless fruits. In this book chapter, we have discussed RNAi and its applications in crop improvement.