title: Species-specific glucosylation of DIMBOA in larvae of the rice Armyworm.
abstract: DIMBOA [2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one] is a benzoxazinoid (Bx), part of the chemical defense system of graminaceous plants such as maize, wheat, and rye. When Bombyx mori larvae were fed artificial diets containing DIMBOA, they died in three days. In contrast, Mythimna separata larvae, a serious pest of rice, maize, sorghum, wheat etc., grew well on the same diets. Three kinds of glucosides [1-(2-hydroxy-4-methoxyphenylamino)-1-deoxy-beta-glucopyranoside-1,2-carbamate (methoxy glucoside carbamate), 2-O-beta-glucopyranosyl-4-hydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA-2-O-Glc), and 2-O-beta-glucopyranosyl-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (HMBOA-2-O-Glc)] were identified by LC-MS and NMR analyses from the frass of M. separata that had been fed on a DIMBOA-containing diet. Furthermore, the incubation of DIMBOA with a midgut tissue suspension of M. separata in the presence of UDP-D-glucose generated DIMBOA-2-O-Glc. These findings strongly suggest that glucosylation by UDP-glucosyltransferase(s) was important for detoxification to circumvent the defenses of host plants against M. separata larvae.
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Sasai
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ishida
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Murakami
authors.forename: Naoko
authors.initials: N
authors.lastname: Tadokoro
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ishihara
authors.forename: Ritsuo
authors.initials: R
authors.lastname: Nishida
authors.forename: Naoki
authors.initials: N
authors.lastname: Mori
mesh_terms: D000818:Animals; D048588:Benzoxazines / Q000378:metabolism*; D012831:Bombyx / Q000254:growth & development / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D005947:Glucose / Q000378:metabolism*; D007814:Larva / Q000378:metabolism*; D013045:Species Specificity; D013056:Spectrophotometry, Ultraviolet
chemical_list: D048588:Benzoxazines; D005947:Glucose; C050733:2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one