基因改造芥藍之安全性評估及檢定

Abstract

自從基因改造作物開始商業化種植，其發展趨勢即逐年快速增長。基於食品安全上的考量，欲上市之基因改造作物必須經過嚴格的食用安全性評估，並利用準確的檢驗方法配合各國法定規範加以管理、標示。基因改造芥藍為臺灣大學葉開溫教授研究室開發之具抗蟲特性的芥藍，其轉殖蛋白 sporamin 可抑制胰蛋白酶活性而影響昆蟲消化。本研究以探討轉殖基因來源、胺基酸序列比對、模擬消化液實驗評估其是否具致過敏性；並與非基因改造芥藍比較營養成分含量，評估其是否實質等同 (substantial equivalence)。本研究利用網路資料庫搜尋基因改造芥藍轉殖蛋白 sporamin 之來源甘藷以及芥藍本身皆無相關致過敏紀錄；而 sporamin 之胺基酸序列比對結果只有過敏原 Sola t 4 與 Gly m TI 與其有較高之相似性；而模擬消化液實驗則顯示 sporamin 蛋白熱不穩定與易被消化的性質，不符合一般過敏原之特性。本研究對基因改造芥藍與非基因改造芥藍之主要營養成分包括水分、灰份、粗蛋白質、粗脂肪、膳食纖維、碳水化合物、維生素 A、維生素 B6、維生素 B12 與維生素 C 進行含量比較，結果皆無顯著差異。定性檢測系統以 sporamin 基因為目標設計引子對 spo137F/spo137R，對基因改造芥藍 DNA 樣品之靈敏度可達 0.5 ng。基因改造芥藍之定量系統建立，以 TaqManTM 與 SYBR Green I 系統所建立之定量方法，在本研究中同樣對於基因改造芥藍定量有良好的表現，其檢測範圍為 0.5% 至 100% 之基因改造芥藍，符合歐盟與我國對基因改造食品標示標準之要求。

The development of genetically modified (GM) crops increases year by year since the commercial genetically modified crops beginning planted. However, for the concern of human health, safety assessment of GM food and development of detection system is necessary before it enter the market. Laboratory of professor Yeh had developed the insect-resistant kale by expressing the sporamin gene. In this study, we check the safety of the GM kale by search for allergic reaction reports and compare the amino acid sequence with allergen in database. The result showed that the sporamin is similar to Sola t 4 and Gly m TI by sequence alignment. But the heat-unstable and easy-digest character of sporamin is not alike allergen. For nutrient composition analysis, GM kale and wild type kale have not shown the difference on content of water, ash, protein, fat, dietary fiber, carbohydrate, vitamin A, vitamin B6, vitamin B12 and vitamin C. We use the primer pair spo137F/spo137R for qualitative analysis. The detection limit of qualitative system is 0.5 ng DNA for GM kale. Two quantitative methods, TaqManTM and SYBR Green I, based on real-time quantitative PCR were used for GM kale. Quantification range was from 0.5% to 100%. The results showed good quantitative performance in these two methods.