Suppression of camptothecin biosynthetic genes results in metabolic modification of secondary products in hairy roots of Ophiorrhiza pumila
Suppression of camptothecin biosynthetic genes results in metabolic modification of secondary products in hairy roots of Ophiorrhiza pumila
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DOI：
10.1016/j.phytochem.2012.04.019
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发表时间：
2013-07-01
期刊：
影响因子：
3.8
通讯作者：
Yamazaki, Mami
中科院分区：
文献类型：
--
作者：
Asano, Takashi;Kobayashi, Kanae;Yamazaki, Mami
喜树碱是一种具有抗肿瘤活性的吲哚类单萜生物碱。矮蛇根草毛状根中喜树碱及其相关生物碱的产量较高，而毛状根细胞悬浮培养中喜树碱及其相关生物碱的产量较低。为了鉴定喜树碱生物合成的中间产物，抑制了喜树毛状根中编码色氨酸脱羧酶（TDC）和裂殖酸合酶（SLS）的基因的表达。利用RNA干扰技术（RNAi），研究了不同浓度的pumila的代谢产物的变化。在大多数TDC-和SLS-抑制线，喜树碱和相关生物碱，strictosidine，strictosamide，pumiloside，deoxypumiloside的积累减少。裂叶马钱素的积累水平与TDC的表达水平呈强负相关，马钱素的积累水平与SLS的表达水平呈负相关。液相色谱-傅立叶变换离子回旋共振质谱（LC-FTICR-MS）检测到的毛状根特异性色谱峰与TDC表达呈正或负相关，表明其可能参与喜树碱的生物合成。(C)2012爱思唯尔有限公司保留所有权利。
Camptothecin is a monoterpenoid indole alkaloid that exhibits anti-tumor activity. In Ophiorrhiza pumila, production of camptothecin and its related alkaloids was high in the hairy roots, but not in the cell suspension culture derived from hairy roots. To identify the intermediates in camptothecin biosynthesis, expression of genes encoding tryptophan decarboxylase (TDC) and secologanin synthase (SLS), the two enzymes catalyzing the early steps in camptothecin biosynthesis, were suppressed in the hairy roots of O. pumila by RNA interference (RNAi), and metabolite changes were investigated. In most TDC- and SLS-suppressed lines, accumulation of camptothecin and related alkaloids, strictosidine, strictosamide, pumiloside, and deoxypumiloside was reduced. The accumulation levels of secologanin exhibited a strong negative correlation with the expression level of TDC, and that of loganin exhibited a negative correlation with the expression level of SLS. Some hairy root-specific chromatographic peaks detected by liquid chromatography Fourier transform ion cyclotron resonance mass spectrometry (LC-FTICR-MS) exhibited positive or negative correlation with TDC expression, suggesting their possible involvement in camptothecin biosynthesis. (C) 2012 Elsevier Ltd. All rights reserved.