The Effects of Water-Deficit Stress on Cannabis sativa L. Development and Production of Secondary Metabolites: A Review

Water-deficit stress is typically viewed as detrimental to agricultural yields. It has been found to enhance secondary metabolite concentrations in certain essential oil-producing plants, including Cannabis sativa L. Cannabis is a versatile plant from the Cannabaceae family which is used for its fibers, seeds, and bioactive compounds, including medicinal and recreational cannabinoids. Furthermore, it exhibits significant metabolic shifts under water-deficit stress conditions, which may impact the production of these resources. This review explores the physiological mechanisms underlying the metabolic responses of cannabis to water-deficit stress, focusing on how water-deficit stress could promote the accumulation of secondary metabolites. Water-deficit stress induces metabolic changes in cannabis, leading to secondary metabolite accumulation. Water shortages cause stomatal closure, significantly reducing CO2 uptake and fixation via the Calvin cycle and leading to an oversupply of NADPH+H+. This oversupply allows metabolic processes to shift toward synthesizing highly reduced compounds, such as secondary metabolites. Overall, the literature suggests that the controlled application of water-deficit stress during cannabis cultivation can enhance cannabinoid quality and yields, offering a practical strategy for optimizing plant productivity while addressing current knowledge gaps in metabolic signaling pathways.