Molecular cloning of a novel GSK3/shaggy-like gene from Triticum monococcum L. and its expression in response to salt, drought and other abiotic stresses
The glycogen synthase kinase 3 (GSK3)/SHAGGY-like kinases are nonreceptor serine/threonine protein kinases that are involved in a variety of biological processes. Here, a novel GSK-3-like kinase encoding cDNA was isolated from Triticum monococcum L. seedlings by reverse transcriptase polymerase chain reaction (RT-PCR). Sequence analysis showed that the full length of cDNA consist of 1,543 bp with an open reading frame of 1,068 bp, which encodes 355 amino acid residues. The deduced amino acid sequence showed a high homology with shaggy-like kinases from Triticum aestivum, Zea mays, Trifolium repens, Nicotine tabacum, Medicago sativa and Arabidopsis thaliana; therefore, the gene was named TmGSK1 (Triticum monococcum Glycogen Synthase Kinase 1,GenBank Accession No. DQ443471). Southern blot analysis indicated that there was only one copy of TmGSK1 in the einkorn wheat genome. Quantitative real-time RT-PCR studies showed that the expression of TmGSK1 in the einkorn wheat was induced by salt stress, mechanical wounding, ABA hormone, cold and drought. These results suggest that cells accumulate more TmGSK1 mRNA response to those abiotic stresses. TmGSK1 was shown to be a positive regulator commonly involved in the tolerance to salt, mechanical injury, ABA hormone, cold and drought in einkorn wheat.
Key words: TmGSK1, abiotic stress, shaggy-like kinase, signal transduction, Triticum monococcum L.