Abstract
Tropical pitcher plants (Nepenthes) catch animals in
their specialized cup-shaped leaves, digest the prey by
secreting enzymes, and actively take up the resulting
compounds. The benefit of this behaviour is the ability
to grow and compete in nutrient-poor habitats. Our
present in vitro study shows that not only the nitrogen
of alanine fed to the carnivorous organs is used by the
plant but that in addition intact C2-units derived from
C-2 and C-3 of stable isotope labelled L-alanine serve as
building blocks, here exemplarily for the synthesis of
the secondary metabolite plumbagin, a potent
allelochemical. This result adds a new facet to the
benefit of carnivory for plants. The availability of
plumbagin by a de novo synthesis probably enhances the
plants' fitness in their defence against phytophagous and
pathogenic organisms. Amissing specific uptake of CoA
activation mechanism might be the reason that acetate fed
to the pitchers was not incorporated into the
naphthoquinone plumbagin. The dihydronaphthoquinone
glucosides rossoliside and plumbaside A, here isolated
for the first time from Nepenthes, by contrast, showed no
incorporation after feeding of any of the two precursors,
suggesting these compounds to be storage forms with
probably very low turnover rates.
Original language | English |
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Pages (from-to) | 603-609 |
Journal | Phytochemistry |
Volume | 59 |
Issue number | 6 |
DOIs | |
Publication status | Published - 2002 |
MoE publication type | A1 Journal article-refereed |
Keywords
- Nepenthes insignis; Nepenthaceae; Carnivory; L-Alanine uptake; Naphthoquinones; Plumbagin; Phytoalexin; Secondary metabolism