title: UV-B impact on aphid performance mediated by plant quality and plant changes induced by aphids.
abstract: Plants face various abiotic and biotic environmental factors and therefore need to adjust their phenotypic traits on several levels. UV-B radiation is believed to impact herbivorous insects via host plant changes. Plant responses to abiotic challenges (UV-B radiation) and their interaction with two aphid species were explored in a multifactor approach. Broccoli plants [Brassica oleracea L. convar. botrytis (L.), Brassicaceae] were grown in two differently covered greenhouses, transmitting either 80% (high UV-B) or 4% (low UV-B) of ambient UV-B. Three-week-old plants were infested with either specialist cabbage aphids [Brevicoryne brassicae (L.), Sternorrhyncha, Aphididae] or generalist green peach aphids [Myzus persicae (Sulzer), Sternorrhyncha, Aphididae]. Plants grown under high-UV-B intensities were smaller and had higher flavonoid concentrations. Furthermore, these plants had reduced cuticular wax coverage, whereas amino acid concentrations of the phloem sap were little influenced by different UV-B intensities. Cabbage aphids reproduced less on plants grown under high UV-B than on plants grown under low UV-B, whereas reproduction of green peach aphids in both plant light sources was equally poor. These results are likely related to the different specialisation-dependent sensitivities of the two species. The aphids also affected plant chemistry. High numbers of cabbage aphid progeny on low-UV-B plants led to decreased indolyl glucosinolate concentrations. The induced change in these glucosinolates may depend on an infestation threshold. UV-B radiation considerably impacts plant traits and subsequently affects specialist phloem-feeding aphids, whereas aphid growth forces broccoli to generate specific defence responses.
authors.affiliation: Julius-von-Sachs Institute of Biosciences, University of Würzburg, Würzburg, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Kuhlmann
authors.forename: C
authors.initials: C
authors.lastname: Müller
mesh_terms: D000818:Animals; D001042:Aphids / Q000502:physiology*; D019607:Brassicaceae / Q000737:chemistry* / Q000528:radiation effects*; D005419:Flavonoids / Q000737:chemistry; D005961:Glucosinolates / Q000737:chemistry; D052585:Phloem / Q000737:chemistry; D014466:Ultraviolet Rays; D014885:Waxes / Q000737:chemistry
chemical_list: D005419:Flavonoids; D005961:Glucosinolates; D014885:Waxes