Associate Professor Karachi Institute of Biotechnology and Genetic Engineering, University of Karachi, Karachi Karachi, Sindh, Pakistan
Body of Abstract: Root exudation facilitates the crosstalk between plant and soil microbes to improve stress tolerance in crops. These interactions are important to explore the potential of root exudates for developing sustainable management practices under abiotic stresses. The following study is designed to identify compounds/signals present in the root exudates of two different wheat varieties - Pakistan-13 (susceptible) and Dharabhi-11 (tolerant) under varying drought conditions at anthesis stage. Morphological and yield analysis was carried out and drought stress tolerance indices were calculated. Root system architecture along with anatomical adaptations were also investigated under depleting soil moisture conditions in both varieties. Gas Chromatography-Mass Spectrometry (GC-MS) was used to quantify stress-related volatile metabolites from the rhizosphere in both wheat cultivars and data was analyzed through Principal Component Analysis ( PCA). Results revealed the Dharabhi-11 exhibited accumulation of wide range of diverse group of key metabolites (137) such as amino acids, alkaloids, organic acids, flavonoids, sugars, organic acids, and sugar alcohols under extreme drought conditions (15 DAI) as compared to Pakistan-13. These metabolites are correlated with potential biochemical pathways, enzymes or gene locations for better understanding of tolerance mechanism. conditions. Combining deep root capability with modified anatomical features such as., lignification of parenchyma cells and thickened vascular cambium helps to cope with drought conditions. Additionally, this variety had a strong root architecture and a diverse metabolite spectrum, which may contribute to its high drought tolerance capacity. These findings will assist in managing drought stress in wheat microhabitats and shape the future for crop breeding and sustainable crop production by enhancing crop resilience and improving stress tolerance in a changing climate.