| Title: | A PIP-family protein is required for biosynthesis of tobacco alkaloids |
| Author(s): | Kajikawa M; Hirai N; Hashimoto T; |
| Address: | "Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara, 630-0192, Japan" |
| DOI: | 10.1007/s11103-008-9424-3 |
| ISSN/ISBN: | 0167-4412 (Print) 0167-4412 (Linking) |
| Abstract: | "Plants in the Nicotiana genus produce nicotine and related pyridine alkaloids as a part of their chemical defense against insect herbivores. These alkaloids are formed by condensation of a derivative of nicotinic acid, but the enzyme(s) involved in the final condensation step remains elusive. In Nicotiana tabacum, an orphan reductase A622 and its close homolog A622L are coordinately expressed in the root, upregulated by methyl jasmonate treatment, and controlled by the NIC regulatory loci specific to the biosynthesis of tobacco alkaloids. Conditional suppression of A622 and A622L by RNA interference inhibited cell growth, severely decreased the formation of all tobacco alkaloids, and concomitantly induced an accumulation of nicotinic acid beta-N-glucoside, a probable detoxification metabolite of nicotinic acid, in both hairy roots and methyl jasmonate-elicited cultured cells of tobacco. N-methylpyrrolinium cation, a precursor of the pyrrolidine moiety of nicotine, also accumulated in the A622(L)-knockdown hairy roots. We propose that the tobacco A622-like reductases of the PIP family are involved in either the formation of a nicotinic acid-derived precursor or the final condensation reaction of tobacco alkaloids" |
| Keywords: | Alkaloids/*biosynthesis/chemistry/*genetics Immunoblotting Molecular Structure Nicotine/chemistry/metabolism Nicotinic Acids/metabolism Phylogeny Plant Proteins/classification/genetics/*physiology Plant Roots/genetics/growth & development/metabolism Plant; |
| Notes: | "MedlineKajikawa, Masataka Hirai, Nobuhiro Hashimoto, Takashi eng Research Support, Non-U.S. Gov't Netherlands 2008/11/13 Plant Mol Biol. 2009 Feb; 69(3):287-98. doi: 10.1007/s11103-008-9424-3. Epub 2008 Nov 12" |
