Isolation And Characterization Of Calcium/Calmodulin-dependent Protein Kinase TaCCaMK Gene In Wheat

Environmental stresses, such as cold, salinity and drought, have an significant impact on crop productivity. Loss of production can also be caused by various diseases. Wheat is the second important crop in China. With an increasing population and the decreasing arable land, it becomes more and more urgent to breed new wheat cultivars that are tolerant to environment stress and diseases. Calcium/calmodulin-dependent protein kinase (CCaMK) belongs to one of those Ca2+ binding proteins. CCaMKs have been reported to play pivotal roles in light-dependent signal-transduction pathway, anther development, symbioses between plant and bacterial/fungal, low temperature and high salinity responses.In this study, we report our work on the gene structure, chromosome localization, subcellular localization, tissure specific expression, gene expression pattern to plant hormone/abiotic/biotic stresses and Arabidopsis transformation of wheat CCaMK (TaCCaMK). The results are as follows:1. The intact open reading frame of wheat TaCCaMK was 1569bp length, which encoded 522 amino acids. TaCCaMK shared 88% similarity with rice OsCCaMK ;2. TaCCaMK contained 7 exsons and 6 introns. The number and the location of introns had no obvious changes in different genome varieties except the size of the introns . The result revealed the conservation of TaCCaMK gene structure as well as CCaMKs from other plant species used for comparison;3. The result of chromosome localization showed that TaCCaMK had at least two copies in the wheat genome;4. The result of sub-cellular localization showed that TaCCaMK was expressed in the plasma membrane, the cytoplasm and the nuclear;5. The expression of TaCCaMK were tissue specific. In five kinds of tissues surveyed, TaCCaMK was found to preferentially express in root tissues, whereas no expression was detected in leaves.6. The expression level of TaCCaMK in root was reduced by treatment with 200μM NaCl, 16%PEG as well as 50μM ABA treatment, suggesting that TaCCaMK may act as a negative regulator of ABA signaling pathway. Salinity and drought stresses might increase endogenous ABA concentration, as inhibited the expression of TaCCaMK. Accordingly the ABA-response signal pathway was activated;7. Root TaCCaMK mRNA levels were not affected by GA treatment, suggesting that TaCCaMK might not participate in GA signal transduction pathway.