Alexander Weinhold

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Plant glandular trichomes exude secondary metabolites with defensive functions, but these epidermal protuberances are surprisingly the first meal of Lepidopteran herbivores on Nicotiana attenuata. O-acyl sugars, the most abundant metabolite of glandular trichomes, impart a distinct volatile profile to the body and frass of larvae that feed on them. The(More)
Treating wounds in Nicotiana attenuata leaves with Manduca sexta oral secretions (W+OS) mimics most changes elicited by M. sexta herbivory, but an unbiased analysis of the effect of the different OS constituents on volatile emissions is lacking. We used two-dimensional gas chromatography/time-of-flight (GCxGC-ToF) mass spectrometry combined with(More)
Mar ıa-Jos e Endara*, Alexander Weinhold, James E. Cox, Natasha L. Wiggins, Phyllis D. Coley and Thomas A. Kursar Department of Biology, The University of Utah, Salt Lake City, UT 84112-0840, USA; Health Sciences Center Core Research Facilities, School of Medicine, The University of Utah, Salt Lake City, UT 84112-0840, USA; and Smithsonian Tropical Research(More)
Plant trichomes are known for their capability to produce and store secondary metabolites that protect plants from biotic and abiotic stresses. 1H NMR studies on intact individual trichomes located on the leaf surface of Nicotiana attenuata revealed the presence of two major secondary metabolites: nicotine, the signature metabolite of the genus, and(More)
UNLABELLED Theoretical and empirical studies show that, when past or current herbivory is a reliable cue of future attack and defenses are costly, defenses can be induced only when needed and thereby permit investment in other functions such as growth or reproduction. Theory also states that, in environments where herbivory is constantly high, constitutive(More)
O-Acyl sugars (O-AS) are abundant trichome-specific metabolites that function as indirect defenses against herbivores of the wild tobacco Nicotiana attenuata; whether they also function as generalized direct defenses against herbivores and pathogens remains unknown. We characterized natural variation in O-AS among 26 accessions and examined their influence(More)
When attacked by herbivores, plants produce toxic secondary metabolites that function as direct defenses, as well as indirect defenses that attract and reward predators of the offending herbivores. These indirect defenses include both nutritive rewards such as extra floral nectar, as well as informational rewards, such as the production and release of(More)
BACKGROUND The present proficiency study aimed to elucidate the comparability and reliability of test systems for the determination of AFP concentrations. METHODS 25 laboratories using 8 different commercial test systems used liquid BIOREF-AFP control serum in their routine internal quality control over a period of one year. For statistical analysis the(More)
This communication deals with a longitudinal evaluation of C-reactive protein (CRP) analysis during a one-year period using a single lot of liquid control sera (3 levels) (BIOREF-CRP levels 1, 2 and 3) in different laboratories. A total of 652 sets of data were returned from 20 participating laboratories using 13 different reagent-measuring device(More)
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