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Selenium hyperaccumulation reduces plant arthropod loads in the field
Author(s) -
Galeas Miriam L.,
Klamper Erin M.,
Bennett Lindsay E.,
Freeman John L.,
Kondratieff Boris C.,
Quinn Colin F.,
PilonSmits Elizabeth A. H.
Publication year - 2008
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2007.02285.x
Subject(s) - arthropod , selenium , biology , botany , ecology , chemistry , organic chemistry
Summary• The elemental defense hypothesis proposes that some plants hyperaccumulate toxic elements as a defense mechanism. In this study the effectiveness of selenium (Se) as an arthropod deterrent was investigated under field conditions. • Arthropod loads were measured over two growing seasons in Se hyperaccumulator habitats in Colorado, USA, comparing Se hyperaccumulator species ( Astragalus bisulcatus and Stanleya pinnata ) with nonhyperaccumulators ( Camelina microcarpa , Astragalus americanus , Descurainia pinnata , Medicago sativa , and Helianthus pumilus ). • The Se hyperaccumulating plant species, which contained 1000–14 000 µg Se g −1 DW, harbored significantly fewer arthropods ( c. twofold) and fewer arthropod species ( c. 1.5‐fold) compared with nonhyperaccumulator species that contained < 30 µg Se g −1 DW. Arthropods collected on Se‐hyperaccumulating plants contained three‐ to 10‐fold higher Se concentrations than those found on nonhyperaccumulating species, but > 10‐fold lower Se concentrations than their hyperaccumulator hosts. Several arthropod species contained > 100 µg Se g −1 DW, indicating Se tolerance and perhaps feeding specialization. • These results support the elemental defense hypothesis and suggest that invertebrate herbivory may have contributed to the evolution of Se hyperaccumulation.