« Previous AbstractBand bending of TiO(2) induced by O-xylene and acetaldehyde adsorption and its effect on the generation of active radicals    Next AbstractEnhanced toxicity and induction of cytochrome P450s suggest a cost of 'eavesdropping' in a multitrophic interaction »

J Chem Ecol

Title:		Allelochemical induction of cytochrome P450 monooxygenases and amelioration of xenobiotic toxicity in Helicoverpa zea
Author(s):		Zeng RS; Wen Z; Niu G; Schuler MA; Berenbaum MR;
Address:		"Key Lab of Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, People's Republic of China. rszeng@scau.edu.cn"
Journal Title:		J Chem Ecol
Year:		2007
Volume:		33
Issue:		3
Page Number:		449 - 461
DOI:		10.1007/s10886-006-9238-1
ISSN/ISBN:		0098-0331 (Print) 0098-0331 (Linking)
Abstract:		"Polyphagous herbivores encounter allelochemicals as complex mixtures in their host plants, and the toxicity of an individual compound may be influenced by the chemical matrix in which it is encountered. Certain plant constituents may reduce toxicity of cooccurring compounds by inducing detoxification systems, including cytochrome P450s, which can metabolize a broad range of substances. The polyphagous corn earworm Helicoverpa zea encounters a diversity of plant allelochemicals in its many host plants and, as well, can encounter aflatoxins, mycotoxins produced by Aspergillus flavus and Aspergillus parasiticus that infect damaged grains. Dietary supplementation of each of three plant allelochemicals that are frequently (coumarin, COU), occasionally (indole-3-carbinol, 13C), or rarely (xanthotoxin, XAN) encountered by H. zea larvae substantially reduced the toxicity of aflatoxin B1 (AFB1) to H. zea. Compared to fourth instars on diets containing 1 microg/g AFB1 that failed to develop and pupate, fourth instars on diets containing I3C and XAN increased in mass by 216.1 and 700% after 6 days, and pupated at rates of 40 and 88%, respectively. Diets containing COU or XAN also significantly reduced the mortality rates of caterpillars exposed to the insecticides, diazinon and carbaryl. Diets containing COU and XAN increased CYP6B8 transcripts 2.6-fold; CYP321A1 transcripts increased 20.7, 8.3, and 10.6-fold in response to COU, I3C, and XAN, respectively. These results indicate that consumption of plant allelochemicals can ameliorate toxicity of natural and synthetic toxins encountered by insects, and they suggest that P450s induced by these allelochemicals contribute to detoxification of these chemicals in H. zea"
Keywords:		"Animals Base Sequence Cytochrome P-450 Enzyme System/*biosynthesis/genetics DNA Primers Enzyme Induction Moths/*drug effects Pheromones/*pharmacology RNA, Messenger/genetics Reverse Transcriptase Polymerase Chain Reaction Transcription, Genetic/drug effec;"
Notes:		"MedlineZeng, Ren Sen Wen, Zhimou Niu, Guodong Schuler, Mary A Berenbaum, May R eng GM071826/GM/NIGMS NIH HHS/ Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2007/01/12 J Chem Ecol. 2007 Mar; 33(3):449-61. doi: 10.1007/s10886-006-9238-1"