To investigate the response mechanism of terpenoid root exudates to salt stress in halophytes， Elytrigia elongata was used as a model species. Gradients of NaCl solutions were applied to soil to simulate control， light， moderate， and severe salt stress conditions. A non-targeted metabolomics approach was employed to identify the profiles and relative abundances of terpenoid compounds in root exudates， and correlations between terpenoid abundance， root morphological traits， and rhizosphere soil physicochemical properties were analyzed. The results showed that compared with the control， the relative abundance of sesquiterpenes， monoterpenes， diterpenes and other terpenoids in root exudates significantly decreased by 8.61%-16.41% under light， moderate and severe salt stress treatments. Triterpenoids and triterpene saponins significantly decreased by 24.54% and 12.43% respectively only under light salt stress. Soil pH emerged as the primary factor influencing terpenoid exudation in Elytrigia elongata. As soil salinity increased， pH decreased， thereby suppressing the secretion of sesquiterpenoids， monoterpenoids， diterpenoids， and other terpenoid classes. These findings provide critical insights into the physiological mechanisms underlying plant adaptation to saline environments.

Salinization  /  Elytrigia elongata  /  Root exudates  /  Terpenoids