Exogenous Application of Plant Metabolites to Enhance Abiotic Stress Tolerance in Plants

Plant metabolites have recently been recognized as effective tools for bolstering food security and mitigating abiotic stress. These small molecules, crucial to plant biochemical processes, have the ability to mitigate the harmful impacts of various abiotic stresses, such as drought, salinity, heat, cold, and heavy metal exposure. The plant metabolites include osmoprotectants, phytohormones, antioxidants, polyamines, and plant growth-promoting rhizobacteria. An exogenous application of osmoprotectants can enhance a plant's resilience to salt and drought, whereas phytohormones provide a pivotal role in orchestrating stress responses and regulating growth. Antioxidants, encompassing compounds like phenolics, tocopherols, and ascorbic acid, can shield plants from oxidative stress, elevating their stress tolerance. Furthermore, certain polyamines, such as spermine and spermidine, have demonstrated their potential to bolster a plant's ability to withstand stressful conditions. However, the effectiveness of exogenously applied plant metabolites may differ based on plant species, stress conditions, timing, and dosage, necessitating further exploration to refine application methodologies and assess long-term impacts on plant growth and yield. Traditionally, high-value crops, including wheat, rice, maize, and various fruits and vegetables, have typically been reliant on plant protection chemicals. These substances, while effective, carry potential risks for both environmental health and human safety. As such, this chapter will delve into the comprehensive research on using plant metabolites for agricultural plants. The focus is to understand how these naturally occurring compounds can be harnessed sustainably to combat today's most pressing environmental challenges.