Isolation And Functional Analysis Of Triae; CYCD2; 1 Gene In Triticum Aestivum L.

Cell cycle is one of the most conspicuous features of life and is usually a hot topic in biological research field. Although recent data have strongly expanded our knowledge of the molecular events of cell cycle in animals and yeasts, it is still poorly understood in plants. Cyclin D genes appeared playing special roles in controlling re-entry into the cell cycle and perceiving developmental and external signals. Although the function of a number of cyclin D genes were investigated in several dicots, little is known about their funcition in monocots. Wheat (Triticum aestivum L.) is an important crop and belongs to monocots. To study the molecular mechanism of cell cycle in this species, we isolated Triae;CYCD2;1(Triticum aestivum CYCLIN D2)gene encoding cyclin D2 protein from wheat.The nearly full-length cDNA of Triae;CYCD2;1 is 1645bp in length and it has the encoding region of 1059 bp. The deduced amino acid sequence of Triae;CYCD2;1 contains 353 amino acid residues. The phylogenetic analysis revealed that the Triae;CYCD2;1 protein is closer to D2 cyclins. Thus, these data suggest that Triae;CYCD2;1 is a cyclin D2 ortholog in wheat. The expression pattern of Triae;CYCD2;1 was analyzed by RNA blot hybridization and in situ hybridization , the results revealed that Triae;CYCD2;1 expression is associated with the proliferation tissues, particularly in meristems and leaf primordia.To explore the function of Triae;CYCD2;1, the gene was transferred to Arabidopsis plants. The homozygous transformants had the phenotypes such as curled leaves and stems, but had relative normal roots. Also, it was found that the emergence of leaves and flowers of transgenic plants was much later than that of wild-type plants. The total life span of the plants with the overexpressing Triae;CYCD2;1 was much longer than that of wild-type plants. Cellular...