Functional genomics to understand the tolerance mechanism against biotic and abiotic stresses in Capsicum species

The Capsicum L. belonging to the family Solanaceae is an economically important genus of flowering plants. This genus comprises more than 30 species with its unique characteristic feature of pungency in its fruits, which are used as spices, in raw salads and pickles. People also use the species of Capsicum for ethnomedicinal and ethnoveterinary purposes. The fruits of Capsicum contain several metabolites including capsaicinoids (alkaloids responsible for the unique pungent taste), vitamins, flavonoids, carotenoids, mineral elements, and other health beneficial compounds, which have medicinal potential. Pharmacological researches have also demonstrated the role of Capsicum in the treatment of many diseases. However, the cultivated species of Capsicum face biotic and abiotic stresses that affect the normal growth and development of the plant and fruits. These stresses negatively affect yields and incur high economic losses to the farmers and the exchequer. Therefore breeding varieties resistant to these stresses is a desirable strategy to avoid/reduce the loss. The development of improved stress-resistant cultivars of Capsicum requires the knowledge of the genetic, genomic, proteomic, and metabolomic basis of stress responses active inside the plants. The recent advancements in high-throughput genomics, proteomics, and metabolomics technologies enable the understanding, quantification, and analysis of genes, proteomes, and metabolomes in various tissues and their response to different stresses at substantial speed and precision. These tools, en masse, known as omics tools allow comparative investigation of wild and cultivated species of plants; thereby in many of the cases could lead to the identification of the genes or proteins and the elucidation of their functions and assisting in the development of multiple stress-tolerant crop designs. In this chapter an attempt has been made to give an overview of the studies currently available toward understating genomic, proteomic, and metabolomic responses to biotic and abiotic stresses in Capsicum species. It further provides insights into designing resistant cultivars using genome editing and other biotechnological approaches.