ROLE AND MECHANISM OF GMHORSTS GENE ON DROUGHT STRESS TOLERANCE OF SOYBEAN

With the frequent occurrence of global drought, some countries and regions are facing reduced soybean production.Therefore, in order to increase soybean yield and ensure global food security, the influence and mechanism of soybean GmHORSTs gene on its drought stress tolerance are analyzed, in order to provide support for improving soybean drought resistance.The experimental results indicated that after drought stress, the fresh weight, dry weight, and water content of pTRV-GmHORSTs were 0.90 g, 0.48 g, and 36.7%,respectively, significantly lower than that of pTRV-00.The content of malondialdehyde and H2O2 were both higher than in pTRV-00, with values of 0.41 umlo/g FW and 13.69 umlo/g, respectively.The fresh weight, dry weight, and water content of GmHORSTs overexpressed plants after drought stress were 1.51 g, 0.59 g, and 61.2%, respectively, all higher than those of wild plants, while their H2O2 and propylene glycol contents were lower than those of wild plants.Under drought stress, the withering degree of pTRV-GmHORSTs was higher than that of normal plants, while the withering degree of over-expressed plants was significantly lower than that of wild plants.In addition, under drought stress conditions, the stomatal conductance of pTRV-GmHORSTs was 19.7 um 2 , which was higher than that of pTRV-00.The stomatal conductance of over-expressed plants was 3.9 um 2 , which was lower than that of wild plants.The abscisic acid content of pTRV-GmHORSTs was 45.3 ng/mL, which was lower than that of pTRV-00.The abscisic acid content of over-expressed plants was 84.8 ng/mL and 84.7 ng/mL, both higher than that of wild plants.The above results indicate that the GmHORSTs gene can increase stomatal closure by increasing leaf abscisic acid content, thereby reducing transpiration and improving soybean drought tolerance.