In common wheat, stem strength is one of the key factors for lodging resistance, which is influenced by lignin content. Cinnamyl alcohol dehydrogenase (CAD) is a vital enzyme in the pathway of lignin biosynthesis. Cloning and marker development of the CAD gene could be helpful for lodging resistance breeding. In this study, the full-length genomic DNA sequence of CAD gene in wheat was cloned by using homologous strategy. A marker 5-f2r2 was developed based on CAD sequence and used to genotype 258 wheat lines. Four haplotype combinations of CAD genes were identified in 258 wheat lines. Correction analyses among the CAD gene expression, CAD activity, and stem strength indicated significant positive correlation between CAD gene expression and CAD activity, between wheat CAD activity and wheat stem strength. The haplotype combination B is significantly associated with the lower enzyme activity and weak stem strength, which was supported by the level of CAD gene expression. The CAD activity and stem strength of wheat could be distinguished to some extent using this pair of specific primer 5-f2r2 designed in this study, indicating that the sequence targeted site (STS) marker 5-f2r2 could be used in marker assistant selection (MAS) breeding.

中文翻译：

---

普通小麦肉桂醇脱氢酶基因的克隆、表达分析及分子标记开发

在普通小麦中，茎秆强度是抗倒伏的关键因素之一，受木质素含量的影响。肉桂醇脱氢酶 (CAD) 是木质素生物合成途径中的重要酶。CAD基因的克隆和标记开发有助于抗倒伏育种。本研究采用同源策略克隆了小麦CAD基因的全长基因组DNA序列。标记5-f2r2是基于CAD序列开发的，用于对258个小麦品系进行基因分型。在 258 个小麦品系中鉴定了 CAD 基因的四种单倍型组合。CAD基因表达、CAD活性和茎强度之间的校正分析表明CAD基因表达与CAD活性之间、小麦CAD活性与小麦茎强度之间显着正相关。单倍型组合 B 与较低的酶活性和较弱的茎强度显着相关，这得到了 CAD 基因表达水平的支持。本研究设计的这对特异性引物5-f2r2可以在一定程度上区分小麦的CAD活性和茎强度，表明序列靶向位点（STS）标记5-f2r2可用于标记辅助选择（MAS） ） 配种。