Metabolomic responses of wheat grains to olive mill wastewater and drought stress treatments

The present research aimed to assess the metabolomic responses of wheat to olive mill wastewater (OMWW) and drought stress treatments. Wheat plants were cultivated under controlled conditions with the following treatments: control (75% field capacity, FC), OMWW (75 ml L^-1), drought stress (40% FC, applied 30 days after sowing), and a combined treatment of OMWW and drought stress. Drought stress alone reduced grain yield by 67%, while the OMWW-treated plants resulted in a 29% reduction under stress relative to the control. OMWW application improved soil properties, enhancing organic matter and nutrient levels. Wheat grains from OMWW-treated plants exhibited higher sugar content and related enzyme activities, indicating improved metabolism, with significant increases in starch, fructose, and glucose levels alongside stable invertase and sucrose phosphate synthase activities. The study also noted substantial changes in amino acids, fatty acids, and phenolic acids in plants subjected to OMWW and drought stress. These modifications indicate OMWW's capability to influence vital biochemical pathways and boost antioxidant capacities in wheat. In conclusion, OMWW proves to be an effective soil amendment that mitigates drought stress and contributes to the production of nutrient-rich, resilient wheat, underscoring its potential as a sustainable agricultural practice in water-scarce areas.