Studies On Cloning Of Salt Tolerant Genes From Populus Euphratica And Transformation Of Populus Popularis

Populus euphratica is the only arbor species which can survive in semi-arid areas in Northwest China. Due to its tolerant to high salinity, Populus euphratica becomes one of the main research interests in the field of plant salt tolerance mechanism. In this dissertation, studies was focused mainly on genes coding for 14-3-3 protein and plasma membrane H~+-ATPase as well as Na~+/H~+ antiporter (PeNHA) from Populus euphratica. Research progress were made mainly on following aspects: Firstly tissue culture and regeneration system of Populus popularis , a salt-sensitive transformation acceptor, was obtained and then based on this system the gene coding Na~+ /H~+ antiporter of Populus euphratica was transferred into Populus popularis by Agrobacerium-mediated transformation approach. The transformation was proved by PCR and PCR-Southern Blotting. Secondly by PCR approach, a 900bp DNA fragment representing the gene coding for 14-3-3 protein was cloned from Populus euphratica . It was then sequenced and proved to be the DNA sequence coding for 14-3-3 protein by Blast analysis. Thirdly screening for gene coding for plasma membrane H~+ATPase of Populus euphratica from cDNA library was conducted and a positive clone with a 999bp insert on the recombinant-vector λ ExCell was obtained, and this insert was speculated to be the plasma membrane H~+-ATPase gene of Populus euphratica. At last, an expression vector containing PeNHA was constructed for expressing PeNHA in Chlorella pyrenoidosa. The results summed up above establish a basis for further thorough illumination of the salt tolerance mechanism of Populus euphratica.