Harnessing CRISPR/Cas9 for Rapid Genetic Improvement of Tomato: From Trait Enhancement to Stress Resilience

Abstract

Tomato (Solanum lycopersicum L.) is a globally important vegetable crop, widely cultivated and consumed due to its rich nutritional profile, including vitamins, carotenoids, and phenolic compounds that contribute to human health. However, its productivity is significantly constrained by a range of biotic stresses, including bacterial, viral, fungal, nematode, and insect infestations, leading to considerable yield losses and deterioration in fruit quality. The narrow genetic base of cultivated tomato further limits the efficiency of conventional breeding programs, which are often time-consuming and labour-intensive despite their success in developing resistant cultivars. In contrast, genome editing technologies enable precise and targeted genetic modifications without the incorporation of foreign DNA. Among these, CRISPR/Cas9 has emerged as a powerful and efficient tool for rapid genetic improvement in tomato. This technology has been widely applied to enhance important agronomic traits, including plant architecture, floral development (e.g., leaf morphology, stem growth, male sterility, fruit set, and parthenocarpy), fruit ripening, and quality attributes such as lycopene, carotenoids, γ-aminobutyric acid (GABA), total soluble solids, anthocyanins, and shelf life. Furthermore, CRISPR/Cas9 has been successfully used to develop resistance against major diseases, including tomato yellow leaf curl virus (TYLCV), powdery mildew, and late blight, as well as to improve tolerance to abiotic stresses such as heat, drought, and salinity. This review summarises recent advances in CRISPR/Cas9-mediated genome editing for enhancing agronomic traits and biotic stress resistance in tomato and highlights its potential for accelerating the development of improved tomato cultivars.