紅檜、台灣扁柏、台灣冷杉、台灣鐵杉和台灣杉caffeoyl CoA 3-O-methyltransferase基因之選殖與序列分析

Gene Cloning and Sequence Analysis of Caffeoyl CoA 3-O-methyltransferase from Chamaecyparis formosensis Matsum., Chamaecyparis obtusa var. formosana, Abies kawakamii, Tsuga chinensis var. formosana an

木質素為植物體內含量僅次於纖維素之重要成分，於木質素生合成過程中，甲基轉移酵素（O-methyltransferase, OMT）扮演相當重要的角色。我們自資料庫中收集並分析已發表之草本和木本植物caffeoyl CoA3-O-methyltransferase（CCoAOMT）序列，在具高保守性的序列中設計了一對引子，並對紅檜、台灣扁柏、台灣冷杉、台灣鐵杉和台灣杉進行OMT基因的釣取，同時配合RACE（Rapid Amplify of oDNA End）的策略，成功獲得紅檜、台灣扁柏、台灣杉的全長基因及台灣冷杉與台灣鐵杉之部分基因片段。由分析比對的結果顯示，此五種台灣現生的針葉樹不論在DNA或者是蛋白質的序列上均具有極高的相似性，此序列資料除了可以提供蛋白質功能區塊的預測，也有助於對本土樹種的親緣關係，分子標記與與生化分類的瞭解。 Lignin is the second most abundant biopolymer, next to cellulose, present in the cell wall of plants. In the stepwise biosynthesis pathway of lignin, O-methyltransferase (OMT) plays a key role. To investigate the mechanism of wood formation and lignin biosynthesis, it is important to understand the function and characteristic of OMT. In the present study, a set of primer was designed based on the conserved region of OMT genes from several woody and non-woody plants, to clone the counter part gene by PCR and RACE (Rapid Amplify of eDNA END) from Chamaecvparis formosensis Matsum., Chamaeeyparis obtusa var. Jormosana, Abies kawakarnii, Tsuga ehinensis var. Jormosana and Taiwania eryptonierioide Hayata. The cloned genes were sequenced and their amino acid sequences predicted. According to the alignment data of nucleotidcs and amino acids sequences, there is a high similarity among the OMT genes from these five species. Thus, our study not only provides valuable information for predicting the protein functional motifs of OMT but also contributes to our understanding of the molecular marker and phylogenetic relationship among these species.

Lignin is the second most abundant biopolymer, next to cellulose, present in the cell wall of plants. In the stepwise biosynthesis pathway of lignin, O-methyltransferase (OMT) plays a key role. To investigate the mechanism of wood formation and lignin biosynthesis, it is important to understand the function and characteristic of OMT. In the present study, a set of primer was designed based on the conserved region of OMT genes from several woody and non-woody plants, to clone the counter part gene by PCR and RACE (Rapid Amplify of eDNA END) from Chamaecvparis formosensis Matsum., Chamaeeyparis obtusa var. Jormosana, Abies kawakarnii, Tsuga ehinensis var. Jormosana and Taiwania eryptonierioide Hayata. The cloned genes were sequenced and their amino acid sequences predicted. According to the alignment data of nucleotidcs and amino acids sequences, there is a high similarity among the OMT genes from these five species. Thus, our study not only provides valuable information for predicting the protein functional motifs of OMT but also contributes to our understanding of the molecular marker and phylogenetic relationship among these species.