DNA shuffling of Arabidopsis thalianna K+ uptake transporter gene
拟南芥K+转运蛋白AtKup1基因的DNA改组

The DNA fragment sized 2139bp which sequence is the same with AtKup1 gene from Arabidopsis thalianna was used as the templates to do DNA family shuffling. The shuffled AtKup1 gene library was expressed in the mutant of S. cerevisae in which potassium transporter gene TRK1 and TRK2 were knocked out by homologous recombination. Then the screening was carried out in the low potassium media containing 5.0 mM KCl and no histidine in it. it was found that both of diverse and wild AtKup1 genes can rescue the trk1 trk2 yeast mutant strain on low K+] medium. The growth of 2 clones yeast contained diverse AtKup1 were beter than that of AtKup1 wild gene transformant. The sequencing results of the shuffled Atkup1 showed that there were 2 nucleotides had changed and resulted in 2 amino acid variations in it compared with original AtKup1. The potassium uptaking capacity of shuffled Atkup1 gene increased significantly when it was transformed into tobacco.