期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2003
卷号：100
期号：12
页码：7027-7032
DOI：10.1073/pnas.1232474100
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：In response to elicitors in the oral secretions of caterpillars, plants produce and release volatile chemicals that attract predators and parasitoids of the caterpillar while it feeds. The most prevalent elicitors are fatty acid amides consisting of 18-carbon polyunsaturated fatty acids coupled with L-glutamine. We demonstrate rapid CoA- and ATP-independent in vitro biosynthesis of the fatty acid amide elicitor, N-linolenoyl-L-glutamine, by microsomal fractions of several alimentary tissues in Manduca sexta. N-linolenoyl-L-glutamine is a structural analog of several other elicitors including volicitin, the first fatty acid amide elicitor identified in caterpillars. The enzyme(s) that catalyzed biosynthesis of N-linolenoyl-L-glutamine was localized within the integral membrane protein fraction extracted from microsomes by Triton X-114 detergent phase partitioning and had maximum activity at alkaline pH. We found no evidence suggesting microbial or tissue-independent biosynthesis of N-linolenoyl-L-glutamine in M. sexta. The in vitro biosynthesis of N-linolenoyl-L-glutamine by membrane-associated enzyme(s) in M. sexta represents direct evidence of fatty acid amide synthesis by caterpillar tissues.
