Isolation And Characterization Of IbP5CS Gene From Sweet Potato And Its Transformation In Arabidopsis Thaliana

Sweet potato is one of the most important food crops in China.The high production and low price makes it to be an important resource for food and industrial production.Sweet potato is always planted in barren land so that it is susceptible to abiotic stress.It is of great significance to study the function of genes involves in responsing to abiotic stress for sweet potato.Δ1-pyrroline-5-carboxylate synthetase(P5CS)is a key enzyme for proline synthesis of plant.Many studies have shown that P5 CS gene are associated with resistance to abiotic stress for plant.The results showed that over-expression of P5 CS gene significantly improved the resistance to abiotic stress and the content of proline in transgenic plants was also increased.Proline is a compatible small molecule involves in osmotic regulation,antioxidant,reduce toxicity and signal transduction and other functions.Proline can quickly accumulate to enhance the resistance to abiotic stress when the plant was under drought,high salt and other non-biological stress conditions.In this study,the complete IbP5 CS gene of sweet potato was successfully cloned by RT-PCR using the relevant P5 CS gene sequence in sweet potato transcriptome and NCBI database.The protein sequence of IbP5 CS was analyzed by bioinformatics softwares.The cDNAs of IbP5 CS were inserted into the pET32a(+)and pYES2 vectors which were transformed into Escherichia coli BL21 and Saccharomyces cerevisiae,respectively.The recombinant proteins of IbP5 CS was successfully expressed by IPTG.The function of IbP5 CS gene was verified when the recombinants were treated by abiotic stress(drought,high salt and high temperature).In order to study the function of Ib P5 CS in plants,pCAMBIA1302-P5 CS was transformed into Agrobacterium tumefaciens that was used to infect the Arabidopsis thaliana.The results showed that the photosynthesis and transpiration of transgenic plants were improved compared with wild type.We will finish the follow-up experiment in the future to study the function of IbP5 CS and provide experimental basis for raising the production of crop.