Advances in Genetic Engineering for Pathogen Resistance in Capsicum annuum L.

Capsicum annuum L. is one of the most consumed vegetable and spice crop species of the family Solanaceae that exhibits a great diversity in colors, shape, and flavors, and grows all across the world. Various biotic stresses including bacterial (such as Xanthomonas campestris pv. Vesicatoria, Ralstonia solanacearum), fungal (such as Phytophthora capsici, Leveillula taurica), viral pathogens (such as cucumber mosaic virus (CMV), potyviruses, tobacco mosaic virus (TMV), and root-knot nematode suppress pepper’s full potential to achieve maximal high-quality yields. Classical plant breeding approaches based on existing genetic variability are time-consuming, laborious, and costly, and have shown limited success, especially for pathogens such as Phytophthora capsici, having complex pathogenesis and high evolutionary rate, due to lack of sexually compatible and completely resistant lines. Alternatively, genetic alteration using genome-engineering tools may provide more efficient and durable resistance to almost all kinds of biotic stresses in peppers. This chapter focuses on recent reports on development of biotic stress-resistant pepper through genetic engineering, for sustainable agriculture. It also discusses the molecular mechanisms of disease development, strategies to develop improved disease-resistant pepper varieties, existing challenges, and future prospects in crop improvement of pepper.