Hydroxamic Acids Derived from 2-Hydroxy-2H-1,4-Benzoxazin-3(4H)-one: Key Defense Chemicals of Cereals

• Published in: Journal of agricultural and food chemistry 2009-03, Vol.57 (5), p.1677-1696
• Main Author: Niemeyer, Hermann M
• Format: Article
• Language: English
• Subjects: 2-hydroxy-2H-1,4-Benzoxazin-3(4H)-one; Agrobacterium tumefaciens; allelochemicals; allelopathy; Animals; Aphids - physiology; Benzoxazines - immunology; Benzoxazines - metabolism; Biological and medical sciences; Cereal and baking product industries; corn; Edible Grain - genetics; Edible Grain - immunology; Edible Grain - metabolism; Edible Grain - parasitology; Food industries; Fundamental and applied biological sciences. Psychology; gene expression; Gene Expression Regulation, Plant; hydroxamic acids; Hydroxamic Acids - immunology; Hydroxamic Acids - metabolism; insect pests; Lepidoptera; literature reviews; Ostrinia nubilalis; pest control; Plant Diseases - immunology; Plant Diseases - microbiology; Plant Diseases - parasitology; plant pests; plant physiology; resistance mechanisms; weed control
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf8034034

Many cereals accumulate hydroxamic acids derived from 2-hydroxy-2H-1,4-benzoxazin-3(4H)-one. These benzoxazinoid hydroxamic acids are involved in defense of maize against various lepidopteran pests, most notably the European corn borer, in defense of cereals against various aphid species, and in allelopathy affecting the growth of weeds associated with rye and wheat crops. The role of benzoxazinoid hydroxamic acids in defense against fungal infection is less clear and seems to depend on the nature of the interactions at the plant−fungus interface. Efficient use of benzoxazinoid hydroxamic acids as resistance factors has been limited by the inability to selectively increase their levels at the plant growth stage and the plant tissues where they are mostly needed for a given pest. Although the biosynthesis of benzoxazinoid hydroxamic acids has been elucidated, the genes and mechanisms controlling their differential expression in different plant tissues and along plant ontogeny remain to be unraveled.