Biosynthesis of Neral in Carpoglyphus lactis (Acari: Carpoglyphidae) and Detection of Its Key Enzyme, Geraniol Dehydrogenase, by Electrophoresis

Abstract

The biosynthetic pathway of neral and its key enzyme(s) in Carpoglyphus lactis were elucidated using a crude enzyme solution obtained from C. lactis. Geraniol, which was biosynthesized via the mevalonate pathway, was first oxidized to geranial, and then geranial was isomerized to neral in C. lactis. Geraniol's geometrical isomer, nerol, was not converted by the crude enzyme solution. The body of C. lactis contained geraniol dehydrogenase (GeDH) dependent on NAD + and a factor that catalyzes the isomerization of geranial to neral. Four GeDHs were found in the crude enzyme solution of C. lactis when subjected to electrophoresis followed by staining with nitro blue tetrazolium and phenazine methosulfate in the presence of geraniol as a substrate. This is the first report of GeDHs from an animal.

Geraniol and Geranial Dehydrogenases Induced in Anaerobic Monoterpene Degradation by Castellaniella defragrans

“…A number of other GeDHs from plant sources (25,43,49) and the insect pest Carpoglyphus lactis (37) are involved in geraniol synthesis and therefore may not have evolved a higher affinity for geraniol than enzymes in degradation pathways. The transformation of ␤-myrcene to geraniol by the linalool dehydratase isomerase is thermodynamically unfavorable and results in a steady state at low geraniol concentrations (7,35), thus requiring a high-affinity GeDH for an efficient metabolic flux.…”

“…Plants synthesize monoterpenes for thermotolerance or other plant-environment interactions in amounts of over 100 Tg C year Ϫ1 ; thus, they represent an important component in the carbon cycle on earth (33,51,54). In insects, monoterpenes are synthesized as pheromones (4,37,50). Furthermore, these substances are widely used in the food, flavor, and fragrance industries due to their odorous properties (8).…”

“…The formation of geranic acid was observed in vivo and in vitro (24), indicating the presence of dehydrogenases catalyzing the oxidation of the allyl alcohol geraniol to geranic acid, most probably via geranial. So far, the only geraniol dehydrogenases (GeDHs) characterized on the molecular level come from sweet basil, Ocimum basilicum (25), and the astigmatid mite Carpoglyphus lactis (37). An aldehyde dehydrogenase acting on geranial has never been reported.…”

Identification of the Alarm Pheromone of Hygia lativentris and Changes in Composition during Development

“…Polyacrylamide vertical slab gel electrophoresis was performed at 4°C according to the method reported by Noge et al (2005) using a hand-cast gel (90×80 mm, 1 mm in thickness) with slight modifications. Briefly, the separating and stacking gels were made of 9.3 and 3.1 % (w/v) of acrylamide, respectively.…”

Influence of the mite Carpoglyphus lactis (L) on the aroma of pale and dry wines aged under flor yeasts

“…According to Kuwahara et al (1980), stress conditions can prompt the emission of 10-50 times the amount of pheromone liberated than when mites are relaxed. Detection of a high concentration of pheromone by C. lactis leads to scattering of the colonies according to Katsuhiko et al (1998), Morita et al (2004) and Noge et al (2005). This scattering might induce mites to fall into the casks and wine biofilm, causing diffusion of neral into the wine.…”