| Soybean(Glycine max) is one of the most important oil crops and fodder crops, which has taken an influential position on farming in the world. In China soybean are produced mainly in northeast part. Because of some external factors such as inappropriate irrigation, vegetation damage and seawater intrusion, a large number of secondary salinization soil have been formed in this area and had seriously affected the acreage and production of soybean. In addition, the conditions such as cold and drought were also the important stress factors which had an influence on soybean growth and development. On the other hand, the incidence of soybean cyst nematode disease has becoming more and more serious because of continuous cropping, which exacerbated the loss of soybean yield further. A basic way to improve the stress tolerance and disease resistance of soybean is to exploit transgenic technology to improve soybean's charaterizations. It is important to isolate and clone stress tolerance genes and transform into soybean to solve this important issue. One of the way to achieve it is to clone the inducible stress promoter and fused with resistance gene to the construction of plant expression vector for transformation into soybean. In this study, we separated and cloned a drought, salt inducible promoter STY from maize and constructed a plant expression vector, which was used to identify the promoter's activity section by tobacco leaf disc transformation method. It provided a genetic material for soybean resistance by genetic improvement. At the same time, we used two Agrobacterium-mediated methods for genetic transformation of soybean with the plasmid containing nematode resistance Bt gene. It established a basis for regeneration further and function verification of exogenous genes in soybean roots. It laid the foundation to resolve the serious multi-stress problems of soybean production in northeast of China. It also provided the bases on the research of carrying out genetic engineering of stress tolerance in soybean at the same time.Results are as follows:1.We have cloned 1675bp 5-flanking region of the salt-inducible protein kinase gene from Maize, named STY. The cis-acting elements were analyzed by the PLACE and PlantCARE;2.To investigate the promoter activity, the full length of STY promoter fragment was transcriptionally cloned into the pCAMBIA1301 binary vector, to create the promoter-GUS fusion construct pCAMBIA1301-STY. The plasmids were transformed into A. tumefaciens EHA105 to identify the promoter's activity section by tobacco leaf disc transformation method with histochemical analysis of GUS activity on resistant shoots;3.We optimized the method with A. tumefaciens EHA105 transforming into the soybean cotyledon used the plant expression vector pBI121-Bt06 which was already constructed. The results as follows: when the cotyledon node pre-culture was 1 day, infected 30 min and the co-culture time was 5 days, the genetic transformation was the highest. The appropriate concentration of Kan was 100mg/L. We obtained seven T1 generation transgenic lines tested through PCR identification which showed positive;4.We tried the method of A. rhizogenes K599 transforming into hypocotyls according to Attila Kereszt and made some slight changes used the plant expression vector pBI121-Bt06 which was already constructed. The results showed that A. rhizogenes K599 can make soybean forming transformation roots which were tested positive by histochemical analysis of GUS activity.
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