The Research Of Cloning Of OsNHX1 Gene And Its Genetic Transformation Into Tomato

Land salinization is one of the important problems in modern agriculture. In order to increase land use efficiency and increase crop yield, it is very important to develop crops with high salt tolerance. In this study, the OsNHX1 gene was cloned from rice, and the gene was transferred into Tomato by Agrobacterium mediated method. NHX gene is one of the important genes related to drought resistance and salt tolerance. NHX gene controls the expression of Na+(K+) /H+, which can promote the accumulation of Na + in the vacuole, and regulate the pH, which can make the salt tolerant ability of the plant. Tomato belongs to the Solanaceae,Solanum L. The cultivation of tomato have a large area of the plant. Tomato contains carbohydrates, minerals, tomato red element and so on a variety of ingredients, with Jianweixiaoshi, Liangxue Pinggan, heat clearing and detoxifying effect. Because of the advantages of self- pollination, chromosome mapping, genetic transformation,easy cultivation, and so on, which is one of the most studied models in biology.The results of this study are as follows:(1) The logarithm growth period of OsNHX1 containing the gene of Agrobacterium was10 to15 hours,the Agrobacteriuma in this period can be used for the transformation of the Agrobacterium;(2) Screening of tomato regeneration mediumGermination medium: 1/2MS solid medium;Regeneration medium: MS solid medium(3% sucrose) IAA+2mg/L 6-BA+0.2mg/L;Co-culture medium: MS solid medium(3% sucrose) IAA+2mg/L6-BA+0.2mg/L AS +0.2mg/L;Rooting medium: MS solid medium(3% sucrose) NAA+100mg/L Cef+0.1mg/L(3) Determination of the conditions of transformationOD600=3.0 +0.2mg/L(MS) IAA+2mg/L 6-BA, pre culture for 2days, infection for 8 min, and co culture for 4 days;(4) Obtaining and testing of resistant plantsBy the transformation of tomato explants, 190 resistant shoots were obtained,and 28 strains of resistant plants were obtained after transplanting.OsNHX1 gene was preliminary confirmed by PCR to integrate into the tomato genome;Further confirmed target gene was integrated into different sites of tomato genome by blot Southern hybridization assay;The expression of OsNHX1 gene in RNA was confirmed by RT-PCR assay.(5) Salt tolerance test of resistant plantsCompared with wild type, the results showed that the seed germination rate was not significantly different from that of the wild type, but the average germination time was 2 days earlier than that of the wild type. The results showed that the OsNHX1 gene increased the salt tolerance of tomato plants.In this study, the tomato regeneration and transformation system were established, and the OsNHX1 gene was successfully transferred into tomato, and it increased the salt tolerance of plant, and laid a theoretical foundation for the cultivation of high salt tolerance crops. But the mechanism of salt tolerance in plants has not been well studied, and many genes have not been cloned. Therefore, it is necessary to research futher to improve the salt tolerance of plants by transgenic.