肉桂醇脱氢酶(cinnamoyl alcohol dehydrogenas, CAD)是木质素生物合成过程中的一类关键酶。采用RT-PCR及RACE方法从孝顺竹笋中分离出CAD基因家族的一个基因, cDNA全长是1 131 bp (GenBank注册号为GU985522), 含有一个1 107 bp的读码框, 编码一个368 aa的蛋白, 分子量约为39 kD。序列分析结果表明, 其编码的氨基酸含有CAD类基因所具有的醇脱氢酶GroES-like结构域和锌结合脱氢酶结构域, 与禾本科植物水稻、玉米等有很高的相似性, 与水稻相似性高达97.0 %。系统进化树分析同样表明, 克隆的孝顺竹CAD基因与水稻的CAD基因的亲缘关系最为接近。组织特异性表达分析显示, CAD基因在孝顺竹笋中表达量最高, 在茎、叶和杆箨中亦有低水平表达。本研究将为更深入的研究孝顺竹CAD基因的分子调控研究奠定基础。

Cinnamoyl Alcohol Dehydrogenas is a key enzyme in the biosynthesis of lignin. A gene of CAD gene family was cloned by RT-PCR and SMART RACE RT-PCR from the shoots of Bambusa multiplex (Lour.)Raeuschel (GenBank accession number: GU985522). The cloned CAD gene of Bambusa multiplex (Lour.) Raeuschel,with the cDNA length of 1 131 bp, contained an open reading frame of 1 107 bp which encoded a polypeptide of 368 amino acids with predicted molecular mass of 39 kD. The results of sequence analysis showed that the deduced polypeptide contained alcohol dehydrogenase GroES-like domain and zinc-binding dehydrogenase in the conserved sequences of the CAD family .It was highly homologous to the CAD proteins from O.sativa and Zea mays and its identity to CAD proteins from O.sativa was up to 97.0 ％.The phylogenetic tree analysis also indicated that cloned CAD gene has most close relationship with the CAD gene in O.sativa. Tissue specific expression showed that CAD expressed in leaf, sheath, young stem and bamboo shoots, much higher in bamboo shoots．All the study will provide a theoretical basis for further studying molecular regulation mechanism of the CAD gene and for taking advantage of its function by gene engineering technique.