细胞分裂素对金钗石斛开花及其VRN1-like基因表达的影响

Cloning and Expression Analysis of a VRN1-like Gene from Dendrobium Nobile

以金钗石斛类原球茎为材料,通过同源克隆分离其VRN1-like同源基因,利用半定量RT-PCR分析细胞分裂素20 mg/L的噻重氮苯基脲(Thidiazuron)对该基因在腋芽和类原球茎中表达的影响.结果表明,喷施TDZ可以代替低温处理诱导金钗石斛开花;金钗石斛VRN1-like基因DnVRNA的cDNA编码的蛋白与高羊茅(Festuca arundinacea)和小麦(Triticum monococcum)中VRN1蛋白的氨基酸序列一致性分别为63%和62%.DnVRNA在腋芽中的表达受TDZ的促进,而在类原球茎中,其表达也受到细胞分裂素和低温的诱导,暗示该基因可能参与细胞分裂素替代低温诱导金钗石斛成花的生物学过程.

Effects of thidiazuron （TDZ） on flowering of Dendrobium nobile were investigated, by spraying on leaves with a concentration of 20 mg/L; and to further investigate the molecular mechanism of the process, the VRNl-like gene was cloned from protocorm-like bodies （PLBs） of Dendrobium nobile, the effects of cytokinins on its expres-sion in axillary buds and PLBs were studied using semi-quantitative RT-PCR analysis. ,The results showed that flow-ering of D. nobile could be induced by application with TDZ instead of cold; the full-length cDNA of a VRNl-like gene named DnVRNA （GenBank accession No. EF535598 ） was cloned, which encodes a peptide with 63% and 62% similarity to the VRN1 protein from Festuca arundinacea and Triticum monococcum, respectively. Semi-quan-titative RT-PCR analysis showed that the expression of DnVRNA in axillary buds was improved by TDZ, and those in PLBs were also up-regulated by cytokinins and cold, which suggested that it would function in cytokinin-induced floral transition.