The Role of a Novel Gene, GmXTH-like26, in Improving Salt Tolerance in Soybean

Soybean is an important crop for food, oil and feed production in China, and improving its yield is a major national goal. Salt stress severely restricts soybean production. XTH genes participate in plant growth and stress adaptation, yet the functions of most soybean XTH members are unclear. In this study, we cloned the soybean GmXTH-like26 gene previously identified via transcriptome sequencing, and successfully constructed its overexpression vector and CRISPR/Cas9 gene-editing vector. Subcellular localization analysis confirmed that GmXTH-like26 is localized to the cell wall. The gene was transformed into soybean via the Agrobacterium-mediated method. Under 100 mM NaCl stress, the GmXTH-like26-overexpressing lines exhibited markedly enhanced salt tolerance at both germination and seedling stages compared with the control group. Physiological and biochemical assays showed that the overexpression plants had higher activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), lower malondialdehyde (MDA) content and higher chlorophyll content under salt stress, while the gene-edited lines displayed the opposite trends. These results indicate that GmXTH-like26 improves salt tolerance in soybean by reducing reactive oxygen species accumulation and effectively enhances the resistance of soybean to salt stress.