Accumulation Of Dehydrins In Turfgrass Under Dehydration And Transformation Of Creeping Bentgrass With AVP1 Gene Driven By Rd29A Promoter

Turfgrass play more and more important roles in our daily life. As the lack of water becomes a major limitation of the the growth of them, to study on the drought resistance in turfgrass is necessary, and it would also be important to develop new kind of drought-enduring turfgrass.In this paper, the accumulation of heat-stable proteins and dehydrins of three kinds of turfgrass under dehydration treatment was detected. And the high efficient system of plant regeneration of turfgrass was established. In order to acquire a drought-enduring turfgrass, AVPl gene driven by rd29A promoter from Arabidopsis thaliana was introduced into creeping bentgrass by Agrobacterium tumefaciens.The primary results could be summarized as follows:1. Water content (gH₂O/gDW) was linear with drying time during the slow desiccation treatment of three kinds of turfgrass callus. The amount of heat-stable proteins increased significantly in two cold-season turfgrass when the water content dropped to 10%, however, the 35kDa heat-stable protein in burmudagrass was decreased. Result from western-blot detection showed that dehydrins were accumulated in all the three turfgrass after the desiccation treatment. Their molecular masses ranged from 18.5 to 34.3kDa. The differences of heat-stable proteins and dehydrins between cold-season and warm-season turfgrass might contribute to their different drought- tolerance mechanisms.2. A tissue culture system for callus induction was developed. The results showed that embryogenic callus could be induced from seeds of creeping bentgrass and tall fescue at high frequency of 53.0±8.7% and 60.7±7.9%. And their callus growth rate could reach the level of 206.0±43.7% and 159.3±34.4%. Differently, the callus induced from seeds of burmudagrass was non embryogenic, with a very low induction rate of 14.7 ±4.0%. And its callus growth rate was only 78.4± 23.2%. Embryogenic callus of burmudagrass could only be induced from nodal segments, while this callus would turn to non-embryogenic callus after several generations.3. The rd29A promoter and AVP1 gene were cloned from Arabidopsis thaliana, and they were placed into pCambial302 vector to establish plant expression vectors.4. The AVP1 gene driven by rd29A promoter was transformed into creeping bentgrass respectively mediated by Agrobacterium tumefaciens. 280 transgenic plants with rd29A promoter regenerated from resistant callus were obtained, and 17 of them were found to be positive by PCR analysis. 450 transgenic plants with AVP1 gene driven by rd29A promoter were obtained, and 4 of them were positive by PCR analysis.