Abiotic Stress-Induced Alterations in Growth, Water Relations, Yield, and Physico-Biochemical Parameters in Opophytum forakahlii

This study investigates the effects of combined drought and heat stress on growth, physiology, biochemistry, and yield of Opophytum forakahlii. It is reported that stress conditions significantly reduced plant height, biomass, leaf area, and photosynthetic efficiency. Physiological traits such as membrane stability, water use efficiency, and relative water content declined, while leaf water potential increased, reflecting impaired water relations. Chlorophyll content and gas exchange traits were also reduced. Biochemical analysis revealed that stress imposition elevated oxidative stress markers and levels of osmoprotectants, soluble sugars, proteins, and antioxidant enzymes. The rise in oxidative stress markers alongside the accumulation of osmoprotectants and antioxidants indicates an activated defense response; however, these adaptations were inadequate to prevent yield reduction and decline in seed nutritional quality, seed yield, proximate composition, and nutrient content decline, with drought exerting a stronger effect than heat. These results highlight the vulnerability of O. forakahlii to future climate stress conditions and underline the need for stress-tolerant varieties amid sustainable agricultural practices. Further research should focus on identifying stress-related genes in O. forakahlii and related crops under stress conditions.