Current understanding of unlocking the power of melatonin and other phytohormones to boost abiotic stress tolerance in solanaceous vegetable crops

Solanaceous vegetable crops are extensively consumed and cultivated around the world, however they are often subjected towards different abiotic stress conditions including cold, heat, drought, salt and heavy-metals toxicity. These stresses notably affect plant growth, yield, and quality. Novel Phytohormones plays a major role in managing crop responses to abiotic stress conditions, particularly those seen in Solanaceous vegetable crops. In this review, an overview of the physiological, morphological and molecular responses of Solanaceous vegetable crops to abiotic stresses, and the regulatory roles of the novel phytohormones in these responses, is furnished. Furthermore, the impact of abiotic stresses on the biosynthesis, metabolism and signaling pathways of major phytohormones, particularly melatonin (MEL), salicylic-acid (SA), jasmonic-acid (JA), strigolactones (SLs), brassinosteroids (BRs) and gamma-aminobutyric acid (GABA) is discussed. Consequently, phytohormones application remarkably boosts growth status of plant, leaf photosynthetic apparatus, root architecture system, osmolytes accumulation, and secondary metabolites production, and upregulates photosynthesis related gene expression. In addition, phytohormone regulates ascorbate-glutathione cycle and reduces cellular membrane damage, as well as maintains mineral nutrient homeostasis. Overall, the current review delivers a comprehensive overview of the recent studies on regulating roles of phytohormones for abiotic stresses in Solanaceous vegetables crops, which may serve as a valuable resource for researchers and breeders working for the enhancement of crop resilience and productivity in challenging environments.