Genetic Transformation Of Peapy2and The Relevance To Cell Salt Tolerance

Populus euphratica has a higher capacity to tolerate salinity. Previous transcriptional profile showed that apyrase gene (PeAPY) was up-regulated under salinity conditions, indicating that apyrase of P euphratica may play an important role in adapting to salt stress. To analyze the gene function, full length cDNA of PeAPY2was cloned from P. euphratica by RT-PCR....Blast analysis shows that the cDNA encodes apyrase. which is a hydrophobic protein of467amino acids and has an ORF of1404bp. Over-expression of PeAPY2in tobacco BY-2cells improved salt tolerance, but the ability to tolerate hyperosmotic stress that caused by mannitol (200-600mM) was not enhanced. After2weeks of NaCl stress (50-150mM), wild-type cells had lower fresh and dry weights than PeAPY2-transgenic cells. Salt treatment caused a lower reduction of K+and lower increase of Na-in transgenic cells. Under salinity conditions, transgenic cells showed lower membrane permeabilization and higher cell viability compared to wild-type cells. This research reveals that overexpressed PeAPY2gene could improve the ability to tolerate salinity in tobacco cells. Our data provides useful information for the further study on the function of PeAPY2in the salt tolerance of P. euphratica.