DROUGHT STRESS RESILIENCE AND ADAPTIVE MECHANISMS IN WHEAT THROUGH GAS EXCHANGE AND BIOCHEMICAL METHODS

Drought stress in wheat plants is a crucial aspect affecting various growth stages of the crop.The current research was aimed to investigate the effects of drought stress on leaf gas exchange and biochemical parameters in three wheat (Triticum aestivum L.) genotypes: two salt-tolerant varieties (W4909 and W4910) and one drought-sensitive variety (Yecora Rojo).Understanding how plants cope with drought is essential with the escalating global warming concerns.The results show that the salt-tolerant varieties, W4909 and W4910, exhibit higher Rubisco efficiency compared to Yecora Rojo, underscoring the importance of Rubisco content in carboxylation efficiency under drought conditions.Furthermore, these salt-tolerant varieties demonstrate greater RuBP regeneration capacity than Yecora Rojo.Significant variations in Rubisco content were noted among the genotypes, with the tolerant varieties maintaining higher levels during drought stress.Additionally, these varieties exhibited higher chlorophyll and total chlorophyll content under drought, enabling them to sustain photosynthesis even under severe stress.Conversely, the tolerant varieties had lower transpiration rates due to stomatal closure, preserving leaf water potential and enhancing photosynthetic rates.Despite a decrease in overall leaf protein content in the tolerant varieties, an increase in Rubisco degradation was observed in Yecora Rojo.Overall, the salt-tolerant varieties showed superior photosynthetic performance, higher Rubisco content, and lower transpiration rates under drought stress, demonstrating their improved water use efficiency and Rubisco efficiency compared to the droughtsensitive Yecora Rojo.