Abstract Detail

Ecological Section

Jhee, Edward [1], Boyd, Robert [2], Eubanks, Micky [3].

Nickel hyperaccumulation as an elemental defense of Streptanthus polygaloides (Brassicaceae): influence of herbivore feeding mode.

No study of a single Ni hyperaccumulator species has investigated the impact of hyperaccumulation on herbivores representing a variety of feeding modes. Streptanthus polygaloides plants were grown on high- or low-Ni soils and a series of no-choice and choice feeding experiments was conducted using eight arthropod herbivores. Herbivores used were two leaf-chewing folivores (the grasshopper, Melanoplus femurrubrum, and the lepidopteran, Evergestis rimosalis), a dipteran rhizovore (the cabbage maggot, Delia radicum), a xylem-feeder (the spittlebug, Philaenus spumarius), two phloem-feeders (the aphid, Lipaphis erysimi, and the spidermite, Trialeurodes vaporariorum) and two cell-disruptors (the bug, Lygus lineolaris, and the whitefly, Tetranychus urticae). Hyperaccumulated Ni significantly decreased survival of the leaf-chewers and rhizovore, and significantly reduced population growth of the whitefly cell-disruptor. However, vascular tissue-feeding insects were unaffected by hyperaccumulated Ni as was the bug cell-disruptor. We conclude that Ni can defend against tissue-chewing herbivores but is ineffective against vascular tissue-feeding herbivores. The effects of Ni on cell-disruptors varies, due either to variation in Ni sensitivity or the location of Ni in S. polygaloides cells and tissues.

1 - 1849 Stancrest Trace Nw, Kennesaw, Georgia, 30152-7676, USA
2 - Auburn University, Department of Biological Sciences, 101 Life Sciences Building, Auburn, Alabama, 36849-5407, USA
3 - Auburn University, Department of Entomology and Plant Pathology, Auburn, Alabama, 36849, USA

Keywords:
hyperaccumulation
nickel
herbivory
feeding mode.

Presentation Type: Poster
Session: 33-34
Location: Salon C, D & E - Gov Ballroom/Hilton
Date: Tuesday, August 16th, 2005
Time: 12:30 PM
Abstract ID:14