Abstract
Under osmotic stress plant avoid it by different modification in their metabolisms such as increasing the synthesis of mRNA of delta 1-pyrroline-5-carboxylate synthase (P5CS), where P5CS is a target gene for increasing proline production and expect to improve the resistance to abiotic stress. To test this hypothesis, grape (Vitis vinifera L.) cv. Thompson Seedless was conducted to develop a protocol for high frequency regeneration and Agrobacterium mediated P5CS gene transfer. Callus induction was achieved by culture leaf explants on Nitsch and Nitsch (NN) basal medium including 2.0 mg L-1 2,4-di-chloro-phenoxy-acetic-acid + 0.5 mg L-1 Thiadiazuron solidified with 2.5 g L-1 phytagel. While for in vitro proliferation of plant, the calli were cultured on NN medium supplemented with 3.0 mg L-1 Zeatin riboside + 0.5 mg L-1 Thiadiazuron. Agrobacterium-mediated transformation using the strain LB4404 harbouring the binary vector pBI121 with the P5CS gene under CaMV 35S promoter and the bar gene as a plant selectable marker was used for transforming grape explants. A P5CS specific band (2100 bp) was amplified from DNA extracted only from the transgenic grape plants and 24% for P5CS gene was positive for the bar gene. Over expression of the abiotic stress P5CS gene was enhanced synthesis of proline to over 6 times higher in transgenic plants compared to controls. The successful transformation of genetically diverse grape cv. Thompson Seedless indicated that the transformation system may have general application to an even wider range of grapes cultivars. (C) 2016 Friends Science Publishers