Cloning of Salt Stress Responsive cDNA from Wheat and Resistant Analysis of Differential Fragment SR07 in Transgenic Tobacco

Analysis of the gene expression differentiation in leaves of wheat (Triticum aestivum L.) cultivar Baofeng 7228, under salt stress, was carried out by Differential-Display Reverse Transcription-polymerase Chain Reaction (DDRT-PCR.) Twenty-seven differential cDNA fragments were obtained. The expression of the SR07 fragment was induced noticeably by salt treatment, and the nucleotide sequence homology of 87% between the SR07 fragment and PIPs (water channel proteins) was observed. Further research showed that a 561 bp open read frame was present in the SR07 fragment. Plant expression vector of pCAMBIA-SR07 was constructed and three transformants of tobacco (Nicotiana tobacum) mediated by Agrobacterium tumefaciens plasmid were obtained. Resistance to salt, PEG, and mannitol stresses of the three transformants were examined. No significant difference (P > 0.05) was observed between the control and the transformants in resistance to salt stress, but there was significant difference (P < 0.05) between the control and the transformants in resistance to PEG and mannitol stresses. Therefore, the expression of the SR07 fragment may play an important role in the water regulation of the plant.