Expression, cloning of PutSnRK2 gene and its protein purification of Puccinellia tenuiflora

In the present study, the full length cDNA of PutSnRK2 gene was cloned from the cDNA library of Puccinellia tenuiflora under the NaHCO3 stress. PutSnRK2 gene contains an open reading frame (ORF) of 1 077 bp, encodes 358 deduced amino acid residues (AARs) with a calculated molecular mass of 41.1 kDa and predicted pI of 5.63. Quantitative real-time PCR (qRT-PCR) analysis showed that the expression of PutSnRK2 gene was significantly induced (P<0.05) in leaves and roots of the P. tenuiflora under stress of NaHCO3, NaCl, ABA, and PEG. At the same time, the prokaryotic expression plasmid of pGEX-6p-3-PutSnRK2 was constructed and transformed into Escherichia coli BL21 (DE3), and GST-PutSnRK2 fusion protein was induced and purified. These results provide foundation for further analyzing the activity of PutSnRK2 and protein-protein interaction.