ausblenden:
Schlagwörter:
-
Zusammenfassung:
More than 87% of flowering plant species are animal-pollinated [1] and produce floral scents and
other signals to attract pollinators. These floral
cues may however also attract antagonistic visitors,
including herbivores [2]. The dilemma is exacerbated
when adult insects pollinate the same
plant that their larvae consume. It remains largely
unclear how plants maximize their fitness under
these circumstances. Here we show that in the
night-flowering wild tobacco Nicotiana attenuata,
the emission of a sesquiterpene, (E)-a-bergamotene,
in flowers increases adult Manduca sexta
moth-mediated pollination success, while the
same compound in leaves is known to mediate
indirect defense against M. sexta larvae [3, 4]. Forward
and reverse genetic analyses demonstrated
that both herbivory-induced and floral (E)-a-bergamotene
are regulated by the expression of a monoterpene-
synthase-derived sesquiterpene synthase
(NaTPS38). The expression pattern of NaTPS38
also accounts for variation in (E)-a-bergamotene
emission among natural accessions. These results
highlight that differential expression of a single
gene that results in tissue-specific emission of
one compound contributes to resolving the
dilemma for plants when their pollinators are also
herbivores. Furthermore, this study provides genetic
evidence that pollinators and herbivores
interactively shape the evolution of floral signals and plant defense.
