Abstract
Hyoscyamine-6β-hydroxylase (H6H; EC 1.14.11.11) catalyses oxidative
reactions in the biosynthetic pathway leading from hyoscyamine to the
more pharmaceutically valuable tropane alkaloid scopolamine. The h6h gene encoding H6H from Hyoscyamus niger was introduced, under the control of the CaMV 35S promoter, into non-hyoscyamine-producing Nicotiana tabacum and hyoscyamine-producing Hyoscyamus muticus. The transformation was performed using a binary vector system based on Agrobacterium rhizogenes. Production of scopolamine in hairy roots was clearly correlated with the 35S-h6h transcript expression. The engineered N. tabacum and H. muticus
hairy roots were studied for the production of scopolamine and other
tropane and nicotine alkaloids after feeding the cultures with exogenous
hyoscyamine. N. tabacum hairy roots carrying the 35S-h6h
transgene showed a more efficient uptake of hyoscyamine from the
culture medium and a higher rate of bioconversion of hyoscyamine to
scopolamine than those of H. muticus. In particular, the secretion of scopolamine in N. tabacum
hairy roots was remarkably high, up to 85% of the total scopolamine
being released to the culture medium. Exogenous hyoscyamine also caused
changes in nicotine alkaloid accumulation in N. tabacum hairy roots.
Original language | English |
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Pages (from-to) | 2611-2618 |
Number of pages | 8 |
Journal | Journal of Experimental Botany |
Volume | 56 |
Issue number | 420 |
DOIs | |
Publication status | Published - Oct 2005 |
MoE publication type | A1 Journal article-refereed |
Keywords
- Hairy roots
- Hyoscyamine-6beta-hydroxylase
- Hyoscyamus
- Nicotiana
- Secretion
- Tropane alkaloids