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The green-fluorescent protein (GFP) from Aequorea victoria has been shown to be a convenient and flexible reporter molecule within a variety of eukaryotic systems, including higher plants. It is particularly suited for applications in vivo, since the mechanism of fluorophore formation involves an intramolecular autoxidation and does not require exogenous(More)
The yeast C-8,7 sterol isomerase contains a polyvalent high-affinity drug binding site similar to mammalian sigma receptors. Exogenously supplied sigma ligands inhibit sterol biosynthesis in yeast, demonstrating a pharmacological relationship between sigma ligand-binding and C-8,7 sterol isomerase activity. We report the isolation of an Arabidopsis thaliana(More)
Plant produced insect molting hormones, termed phytoecdysteroids (PEs), are thought to function as plant defenses against insects by acting as either feeding deterrents or through developmental disruption. In spinach (Spinacia oleracea), 20-hydroxyecdysone (20E) concentrations in the roots rapidly increase following root damage, root herbivory, or methyl(More)
A series of experiments, using GLC, RP-HPLC, and GC-MS techniques, were performed to examine the metabolic fate and absorption of different dietary sterols in the grasshopper Schistocerca americana. In the first experiment, grasshoppers were reared on diets containing different sterols presented singly. Cholesterol was the dominant tissue sterol recovered(More)
Cholesterol oxidase represents a novel type of insecticidal protein with potent activity against the cotton boll weevil (Anthonomus grandis grandis Boheman). We transformed tobacco (Nicotiana tabacum) plants with the cholesterol oxidase choM gene and expressed cytosolic and chloroplast-targeted versions of the ChoM protein. Transgenic leaf tissues(More)
Insect-molting hormones, phytoecdysteroids, have been reported to occur in over 100 plant families. Plants, unlike insects, are capable of the biosynthesis of ecdysteroids from mevalonic acid, and in several cases the biosynthesis of phytoecdysteroids was also demonstrated to proceed via sterols. Spinacia oleracea (spinach) biosynthesizes polypodine B and(More)
Previously, we have shown that the expression of a 3-hydroxysteroid-oxidase gene in transgenic tobacco initiated a series of biochemical events leading to the conversion of sterol to stanol. As a result, the plants maintained a diminished sterol pool and a modified relative sterol ratio but demonstrated no observable morphological abnormalities. The(More)
The symbiotic fungus Amylostereum areolatum is essential for growth and development of larvae of the invasive woodwasp, Sirex noctilio. In the nutrient poor xylem of pine trees, upon which Sirex feeds, it is unknown whether Amylostereum facilitates survival directly through consumption (mycetophagy) and/or indirectly through digestion of recalcitrant plant(More)
Insects lack the ability to synthesize sterols de novo, which are required as cell membrane inserts and as precursors for steroid hormones. Herbivorous insects typically utilize cholesterol as their primary sterol. However, plants rarely contain cholesterol, and herbivorous insects must, therefore, produce cholesterol by metabolizing plant sterols. Previous(More)