地黃毛狀根之建立與培養研究

Abstract

地黃為玄參科植物懷慶地黃之塊根。新鮮的根稱鮮生地，性大寒，味甘苦。曬乾後稱乾地黃，性寒，味甘微苦。生地黃以砂仁和酒拌之，蒸熟後曬乾，稱熟地黃，性溫，味甘。地黃含多種甙類成分，其中以環烯醚帖甙為主，在鮮生地、乾地黃和熟地黃中含量顯著差異，且為地黃的主要活性成份，也是使地黃變黑的成分，如梓醇（catalpol）已被證實具有降血糖的藥效。 地黃的栽培時間大約為一年至一年半，有效成分易隨外在環境不同而有所差異，而利用農桿根群菌（Agrobacterium rhizogenes）感染地黃植株誘導生成的地黃毛狀根，則具有遺傳性質及生合成穩定、生長快速、可控制外在環境等優點。本實驗針對培養環境、植物及細菌等因素進行地黃毛狀根的誘導探討，並以 PCR、GUS 表現以及地黃成分分析來鑑定地黃毛狀根，發現在菌液濃度達 A600 = 0.8、22℃ 下感染地黃葉片外植體（leaf disc）兩天，以 White’s 培養基對地黃毛狀根的誘導率最高，而兩種農桿根群菌（A4, ATCC 15834）對地黃毛狀根的誘導，則並沒有太大的差異。如果在培養過程中，添加植物生長調節素如 2,4-D (2,4-Dichlorophenoxyace- tic acid)，更可以增加毛狀根的誘導率。

Chinese foxglove (Rehmannia glutinosa) is a valuable herb medicine which has been used in traditional Chinese medicine. Hairy root cultures were used as a culture system in vitro for the production of medicinally important compounds to avoid many of the problems that affect the traditional production from field-grown species. We successfully established hairy root cultures of Chinese foxglove by infection with A. rhizogenes. The induction and growth of hairy root were differently affected by basal culture media, the age of plant, plant growth regulators and bacteria. The best induction and growth of hairy roots were obtained on White’s medium with 3% sucrose and 2,4-D (2mg/L). The efficiencies of hairy roots’ induction by A. rhizogenes A4 or ATCC 15834 strain were not different.