Abstract:

The response to low temperature stress in highland barley indicates that there is a potential gene bank for cold resistance, which is helpful to develop the genes associated with resistance to cold and to survey the regulation mechanism. The objective of this study was to exploit a new gene with cold resistance, to validate its function. A pair of primer was designed based on the blt14.2 gene sequence documented in GenBank, a low-temperature-responsive (LTR) gene hblt14.2 was cloned by PCR from highland barley with GenBank accession number EF514912. Its length was 470 bp, containing 249 bp ORF, 69 bp 5'untranslated region (UTR) and 152 bp 3'UTR. Nucleotide sequence of hblt14.2 gene shares 98.9% (only five base pairs difference)homology with that of blt14.2 in barley, which encoded a protein of 82 amino acids. Theprotein was a highly hydrophilic small protein with rich Gly, Ala, Leu and Val amino acids, which were similar to proteins encoded by other LTR genes. The hblt14.2 ligated with CaMV 35S promoter and NOS terminator was inserted into multiple clone site in plasmid CAMBIA1301 to construct plant expression vector pCAMBIA-BI-hblt, which was transformed into tobacco mediated by Agrobacterium tumefaciens. Transgenic plants response to low temperature were investigated. The results suggested that the hblt14.2 is related to cold resistance in highland barley.

Key words: Highland barley, Low temperature, hbltl4.2 gene, Function analysis