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Eicosanoids mediate Manduca sexta cellular response to the fungal pathogen Beauveria bassiana : A role for the lipoxygenase pathway
Author(s) -
Lord, Jeffrey C.,
Anderson Sheri,
Stanley David W.
Publication year - 2002
Publication title -
archives of insect biochemistry and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.576
H-Index - 66
eISSN - 1520-6327
pISSN - 0739-4462
DOI - 10.1002/arch.10049
Subject(s) - biology , lipoxygenase , beauveria bassiana , eicosanoid , microbiology and biotechnology , oxylipin , phytoalexin , arachidonate 5 lipoxygenase , biochemistry , enzyme , resveratrol , botany , arachidonic acid , biological pest control
Many studies have documented the involvement of eicosanoids in insect cellular immune responses to bacteria. The use of the fungal pathogen Beauveria bassiana as a nodulation elicitor, with inhibition of phospholipase A 2 by dexamethasone, extends the principle to fungi. This study also provides the first evidence of involvement of the lipoxygenase (LOX) pathway rather than the cyclooxygenase (COX) pathway in synthesis of the nodulation mediating eicosanoid(s). The LOX product, 5(S)‐hydroperoxyeicosa‐6E,8Z,11Z,14Z‐tetraenoic acid (5‐HPETE), substantially reversed nodulation inhibition caused by dexamethasone and the LOX inhibitors, caffeic acid and esculetin. The COX product, prostaglandin H 2 (PGH 2 ), did not reverse the nodulation inhibition by dexamethasone or the COX inhibitor, ibuprofen. None of the inhibitors tested had a significant effect on the phagocytosis of B. bassiana blastospores in vitro. Hemocyte phenoloxidase activity was reduced by dexamethasone, esculetin, and the COX inhibitor, indomethacin. The rescue candidates 5‐HPETE and PGH 2 did not reverse the inhibition. Arch. Insect Biochem. Physiol. 51:46–54, 2002. Published 2002 Wiley‐Liss, Inc.