利用 EST 及基因微陣列法研究臺灣杉之功能基因(1/3)

臺灣杉 (Taiwania cryptomerioides Hayata) 為臺灣原產重要經濟樹種之一，針對臺灣杉的 抽出成分、生物活性、及其木材性質的研究，已累積相當多的成果。為了進一步了解參與臺 灣杉生理生化機制基因的表現與調控情形，我們乃展開分子層面的探討。首先，藉由構築臺 灣杉苗木之互補DNA 基因庫(cDNA library) 所獲得之表現序列標籤(Expressed Sequence Tags, ESTs)，來進行一初步全面性的探討。至目前為止，由序列分析結果指出，334 個ESTs 中， 有67.4% 與基因資料庫中的基因具同源性。藉由BLASTX 演算及進一步依其假設性功能做 分類，結果顯示，12.2% 的ESTs 與蛋白質之合成與修飾有關，其中包含了高度表現的small heat shock proteins (smHSPs)；有7.2% 的ESTs 與細胞防禦有關，包括高度表現的cysteine proteinase inhibitors、dehydrins 及late embryogenesis abundant proteins；另外，有1.2% 的ESTs 與二次代謝有關。此外，有32.6% 的ESTs 不與基因資料庫中的任何基因具同源性，由此結 果顯示，這些ESTs 可能為臺灣杉所具之獨特基因，也因此更凸顯出臺灣杉於分子生物研究 上的重要性。Taiwania (Taiwania cryptomerioides Hayata), one of the most economically important tree species in Taiwan, had many studies about bioactivities, wood properties and phytochemistry. In order to further understand the genes of physiological and biochemical mechanisms in Taiwania, an expressed sequence tags (ESTs) resource was established by constructing a Taiwania seedling cDNA library firstly. Sequence analyses identified 334 ESTs, of which 67.4% showed homology to previously described sequences in public databases. Analyzed by BLASTX searches and classified functionally, 12.2% of ESTs involved in protein synthesis and processing which included highly expressed smHSPs, 7.2% were similar to the cell rescue and defense including highly expressed cysteine proteinase inhibitors, dehydrins and late embryogenesis abundant proteins, and 1.2% involved in secondary metabolism among identified ESTs of Taiwania. Additionally, 32.6% of ESTs showed no significant similarity to any other protein sequences in public databases. These sequences may indicate the unique genes in Taiwania and revealed the remarkable value of Taiwania