Scopolamine in Brugmansia Suaveolens (Solanaceae): Defense, Allocation, Costs, and Induced Response

• Published in: Journal of chemical ecology Vol. 33; no. 2; pp. 297 - 309
• Main Authors: Alves, Marcos Nopper, Sartoratto, Adilson, Trigo, José Roberto
• Format: Journal Article
• Language: English
• Published: New York, NY New York : Springer-Verlag 01-02-2007; Springer; Springer Nature B.V
• Subjects: Acetates - metabolism; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Biological and medical sciences; Brugmansia; Butterflies & moths; Cyclopentanes - metabolism; Diet; Flowers & plants; Fundamental and applied biological sciences. Psychology; General aspects; herbivore-induced resistance; Herbivores; Herbivory; induced resistance; insect growth; Larva - drug effects; Larvae; larval development; Leaves; methyl jasmonate; mortality; Noctuidae; optimal-defense theory; Oxylipins; pest resistance; phytophagous insects; plant damage; plant defense; Plant Leaves - metabolism; resistance costs; Ricinus; Ricinus communis; scopolamine; Scopolamine Hydrobromide - metabolism; Scopolamine Hydrobromide - pharmacology; Solanaceae; Solanaceae - physiology; Spodoptera - drug effects; Spodoptera - physiology; Spodoptera frugiperda; tissue distribution; tropane alkaloids; Terpenoid; Costs; Herbivorous; Induction; Theory; Induced resistance; Brugmansia suaveolens, Costs of induction, Herbivory; Alkaloid; Dicotyledones; Angiospermae; Induced resistance, Induced responses, Artificial damage, Methyl jasmonate, Optimal-defense theory, Scopolamine, Solanaceae; Plant growth substance; Defense mechanism; Spermatophyta; Solanaceae; Damage; Jasmonic acid; Tropane alkaloids
• ISSN: 0098-0331; 1573-1561
• DOI: 10.1007/s10886-006-9214-9

Brugmansia suaveolens (Solanaceae) contains tropane alkaloids (TAs), which can act as chemical defenses. Selective pressures might modulate the allocation of alkaloids within the plant, as postulated by optimal-defense theory. By tracing scopolamine, the most abundant TA in this species, we found that scopolamine in an artificial diet, in concentrations similar to those in leaves of B. suaveolens, increased mortality and prolonged developmental time of the larvae of the generalist noctuid moth Spodoptera frugiperda. A diet of undamaged leaves of B. suaveolens also showed a large negative effect on the growth of larvae of S. frugiperda compared to a diet of leaves of Ricinus communis, a species that did not have negative effects on this moth; more valuable plant parts, such as young leaves, flowers, and unripe fruits with seeds, have higher scopolamine concentrations than other tissues; leaves of B. suaveolens increase their content of scopolamine after artificial damage. The highest induction was found 24 hr after the damage, and after that, scopolamine content decreased to constitutive levels. This increase represented a cost, because in another experiment, a treatment with methyl jasmonate, an elicitor hormone, increased scopolamine production 9.5-fold and decreased leaf growth 2.3-fold; a diet of artificially damaged leaves of B. suaveolens showed a negative effect on the growth of larvae of S. furgiperda compared to undamaged leaves, suggesting that damage by herbivores induces resistance. Our data are in line with the optimal-defense theory, but experiments in the field with herbivores that share an evolutionary history with B. suaveolens must be undertaken to understand the dynamics of TA allocation in response to herbivory.