Non-induce occurrence of benzoxazinones in non-autotrophic wheat and maize

Research Project

Project/Area Number	08456059
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Research Field	Bioproduction chemistry/Bioorganic chemistry
Research Institution	KYOTO UNIVERSITY
Principal Investigator	IWAMURA Hajime Kyoto Univ., Appl.Life Sei., Prof., 農学研究科, 教授 (30026570)
Co-Investigator(Kenkyū-buntansha)	ISHIHARA Atsusi Kyoto Univ., Appl.Life Sei., Instr., 農学研究科, 助手 (80281103) HIRAI Nobuhiro Kyoto Univ., Appl.Life Sei., Instr., 農学研究科, 助手 (00165151)
Project Period (FY)	1996 – 1997
Project Status	Completed (Fiscal Year 1997)
Budget Amount *help	¥2,000,000 (Direct Cost: ¥2,000,000) Fiscal Year 1997: ¥2,000,000 (Direct Cost: ¥2,000,000)
Keywords	wheat / maize / defense mechanism / benzoxazinones / glucosidase / antifungal substances
Research Abstract	Benzoxazinones are known as defense compounds in wheat, maize and rye, and occur as glucosides. Upon infection or insect attack, they are rapidly hydrolyzed to produce the aglycones. The aglycones exhibit wide range of fugi-and bacteriostatic activity as well as antifeeding activity against insects. In this study, we found that free benzoxazinones occur transiently during non-autotrophic stage of growth. This appearance and disappearance were little affected by infection and wounding, and thus thought to be a programd event. Benzoxazinone glucoside beta-glucosidade activity was identified in extracts of maize and wheat seedlings, and purified to an apparent homogeneity by ion-exchange and gel chromatographies. Characterization made for this fraction revealed that the glucosidase has a very high specificity for benzoxazinone glucosides, indicating that a specific glucosidase occurs for the production of active benzoxazinones in the juvenile stage. Also identified in the extracts were a glucosyltransferase with a high specificity for benzoxazinones. The set of results suggested that benzoxazinones occur in a programd manner as defense at the vulnerable juvenile stage of qrowth, and specific glucosisade and glucosyltransferase are involved in this event.