小麦细胞分裂素氧化/脱氢酶基因（TaCKX5）的克隆及其染色体定位

【目的】克隆小麦的TaCKX基因并对其序列进行生物信息学分析，明确TaCKX基因在小麦基因组中的分布情况，以期为今后深入研究小麦CKX基因以及利用该基因进行小麦重要农艺性状的遗传改良奠定基础。【方法】采用同源克隆结合BAC文库筛选的方法克隆基因，通过小麦缺体-四体对其进行染色体定位。【结果】从普通小麦中国春中分离得到TaCKX5基因的gDNA和cDNA序列。分析表明，TaCKX5基因的开放阅读框为1 596 bp，编码531个氨基酸，含有CKX基因家族典型的功能位点FAD-binding domain，预测属于分泌蛋白，并具有糖基化位点。使用中国春缺体-四体将TaCKX5定位于小麦第三同源群。系统发育分析表明，CKX基因在植物中较为保守，禾谷类作物中直向同源的CKX基因很可能具有相似的特性与功能。【结论】分离获得了普通小麦TaCKX5基因全长，TaCKX5分布于小麦染色体3A、3B、3D上，与水稻OsCKX5基因直向同源。

Isolation and Chromosomal Localization of Cytokinin Oxidase/Dehydrogenase Gene (TaCKX5) in Wheat

【Objective】Genetic manipulation of CKX activity holds the promise of improving agricultural traits in crops.【Method】and【Result】In this study, a strategy of homologous cloning combined with BAC library screening was used to isolate TaCKX5 gene from wheat. Sequence analysis of TaCKX5 revealed that TaCKX5 contains a FAD-binding domain which is well conserved in the N-terminal halves of all known CKX sequences. Using TargetP program, TaCKX5 was predicted to be a secretion pathway protein, and one N-glycosylation site (NFTE) was also found with NetNGly program, implied that TaCKX5 protein may be modified posttranslationally by glycosylation. Using nulli-tetrasomic stocks, TaCKX5 was located on wheat homoeologous group 3 chromosomes.【Conclusion】TaCKX5 was very closely related to its orthologous CKX gene (OsCKX5) in rice, so they might have similar characters and functions.