Construction of genetic transformation system of Lycium barbarum callus

In order to achieve efficient genetic transformation of Lycium barbarum L.and accelerate the process of genetic improvement of L. barbarum . The stem segments of Lycium barbarum were used as materials, and the Agrobacterium-mediated method was used to determine the LB concentration, infection time and co-culture time under the optimal transformation conditions by three-factor and three-level orthogonal test. The genetic transformation system of callus was established, and the effect of LbMYB18 gene overexpression on the physiological metabolism of callus was explored by using this system. (1) The optimal transformation conditions were LB concentration of 2%, infection time of 20 min, and co-culture time of 3 d. The callus formation rate was 96.67%, and the GFP fluorescence positive rate was 53.33%. (2) LbMYB18 gene was successfully integrated and stably expressed, and the expression level was about 5.4 times that of the control group. (3) Physiological analysis showed that the activities of SOD, POD, CAT and the content of MDA in the overexpression lines were significantly higher than those in the control group. The contents of chlorophyll a, chlorophyll b and carotenoids increased significantly. The genetic transformation system of Lycium barbarum was established. Overexpression of LbMYB18 gene can significantly improve the antioxidant capacity of plants and promote the accumulation of photosynthetic pigments. The results provide a technical basis for gene function research and genetic improvement of Lycium barbarum .