Cloning and Functional Study of AmGDSL1 in Agropyron mongolicum

<i>Agropyron mongolicum</i> Keng is a diploid perennial grass of triticeae in gramineae. It has strong drought resistance and developed roots that can effectively fix the soil and prevent soil erosion. GDSL lipase or esterases/lipase has a variety of functions, mainly focusing on plant abiotic stress response. In this study, a <i>GDSL</i> gene from <i>A. mongolicum</i>, designated as <i>AmGDSL1</i>, was successfully cloned and isolated. The subcellular localization of the <i>AmGDSL1</i> gene (pCAMBIA1302-<i>AmGDSL1</i>-EGFP) results showed that the AmGDSL1 protein of <i>A. mongolicum</i> was only localized in the cytoplasm. When transferred into tobacco (<i>Nicotiana benthamiana</i>), the heterologous expression of <i>AmGDSL1</i> led to enhanced drought tolerance. Under drought stress, <i>AmGDSL1</i> overexpressing plants showed fewer wilting leaves, longer roots, and larger root surface area. These overexpression lines possessed higher superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and proline (PRO) activities. At the same time, the malondialdehyde (MDA) content was lower than that in wild-type (WT) tobacco. These findings shed light on the molecular mechanisms involved in the <i>GDSL</i> gene's role in drought resistance, contributing to the discovery and utilization of drought-resistant genes in <i>A. mongolicum</i> for enhancing crop drought resistance.