Inter-regional variation on leaf surface defenses in native and non-native Centaurea solstitialis plants

SOTES GJ; CAVIERES LA; MONTESINOS D; PEREIRA COUTINHO AX; PELÁEZ WJ; LOPES SMM; PINHO E MELO TMVD

BIOCHEMICAL SYSTEMATICS AND ECOLOGY

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2015 vol. 62 p. 208 - 218

0305-1978

Plantchemical defenses can be qualitative (toxins) to face generalist herbivores andquantitative (digestibility reducers) to specialists. Trichomes can producechemicals, but also acts as a quantitative defense and in water loss. The shiftingdefense hypothesis (SDH) poses that invasive plants reduce the production ofqualitative defenses against specialist herbivores because those are frequentlyabsent in invaded regions, while increasing defenses against generalistherbivores. Chemical and physical leaf surface defensive traits could giveinformation about direct planteherbivore interaction in native and non-native regions.We studied leaf surface morphology and epicuticular chemistry of the invasive C.solstitialis in plants from native and non-native regions. Across regions, themain chemical components were sesquiterpene lactones, similar densities ofsessile glandular trichomes and a variable number of large multicellulartrichomes. Exotic plants face different sets of challenges in the new regions.In accordance with SDH, plants from non-native regions presented higher totalsesquiterpene lactones concentrations (qualitative defense). Trichome densitywas possibly associated to differences in local climatic conditions. Sesquiterpenelactones are likely to play an important role on the invasion success of Centaurea.Leaf surface components provide meaningful information that should be considerin future studies to unravel the mechanisms involved in plant invasions.