Physiological and Biochemical Responses of GmXTH1 Overexpression Soybean to Drought Stress at Seedling Stage

In order to study the effect of GmXTH1 gene on the phenotype and physiological and biochemical characteristics of soybean seedlings under drought stress, five transgenic soybean varieties M18, GmXTH1 overexpressing transgenic lines OEA1 and OEA2, GmXTH1 interfering expressing transgenic lines IEA1 and IEA2 were used as experimental materials. We set three different water treatments using the potting method to measure the phenotype of RWC, SOD and POD activity, and MDA content of different transformed lines at the seedling stage. The results showed that with the increase of drought stress, RWC decreased relatively, SOD and POD activity increased firstly and then decreased, and MDA content increased. Under the same drought stress condition, compared with the control M18, OEA1 and OEA2 with overexpressed GmXTH1 gene had higher RWC, higher SOD and POD activity, faster response speed, weaker MDA content, lower growth rate, thicker green leaves, thicker stems, better overall plant type performance, and faster rehydration after drought stress. However, IEA1 and IEA2 with GmXTH1 interference expressed gene were on the contrary. Under drought stress, the overall performance of the plants was as follows: leaf wilted, stem withered and was thin, overall performance of plant type was poor, RWC, SOD and POD activities were relatively low, and response speed was slow. The result indicated that the GmXTH1 overexpressed gene had a positive effect on the physiological and biochemical indexes related to drought resistance of soybean plants, and GmXTH1 gene may be involved in the response to drought stress in soybean.