Abstract: Using total DNA of Porphyra haitanensis thalli as PCR template,three overlapping fragments of its trehalose-6-phosphate synthase(TPS)gene(PhTPS)with size of 1.3,1.1,0.7 kb were amplified by three pairs of DNA primers respectively. After T-A cloning,sequencing and sequence assembly,the full length open reading frame sequence of PhTPS gene was obtained.Without intron,its length is 2 727 bp.Based on the construction of the pro-karyotic expression vector of Porphyra yezoensis TPS gene ( pET22 b-PyTPS ), its PyTPS gene was replaced by PhTPS gene and the prokaryotic expression vector of PhTPS gene(pET22b-PhTPS)was derived.After expression induction of the recombinant E.coli strain BL21(pET22b-PhTPS)with TPTG,a specific band about 100 kDa was found in SDS-PAGE pattern.Salt tolerance of the recombinant strain was detected in the NaCl-containing LB medi-um,visual inspection and OD₆₀₀ determination results indicated that the salt-tolerance of the recombinant strain was significantly higher than that of control E.coli strain BL21(pET22b).The salt tolerance of the recombinant strain was increased by the expression of PhTPS gene.This gene can be used as a salt-tolerant candidate gene in plant ge-netic engineering improvement.

Key words: Porphyra haitanensis, TPS gene, Prokaryotic expression, Recombinant E. coli, Salt tolerance

CLC Number: 

• S917.3