Molecular analysis of CYP321A1, a novel cytochrome P450 involved in metabolism of plant allelochemicals (furanocoumarins) and insecticides (cypermethrin) in Helicoverpa zea

Transposable elements are enriched within or in close proximity to xenobiotic-metabolizing cytochrome P450 genes

“…Previous studies have demonstrated that CYP321A1 is highly inducible by xanthotoxin [23] and the four CYP6B transcripts accumulate to varying degrees in response to a range of allelochemicals naturally encountered in hostplants (xanthotoxin, indole-3-carbinol, chlorogenic acid, flavone) as well as in response to synthetic chemicals not naturally encountered (cypermethrin, phenobarbital) [21,22]. The CYP6B transcripts are also inducible by plant defense signalling molecules jasmonate and salicylate, allowing this species to "eavesdrop" on plant defense signals for activating detoxification systems in advance of induced biosynthesis of host plant toxins [41].…”

“…Transposons within the CYP6B gene cluster Seven P450 genes distributed in the CYP6B, CYP4M, and CYP321A subfamilies have been cloned from H. zea [21][22][23]. Previous studies have demonstrated that CYP321A1 is highly inducible by xanthotoxin [23] and the four CYP6B transcripts accumulate to varying degrees in response to a range of allelochemicals naturally encountered in hostplants (xanthotoxin, indole-3-carbinol, chlorogenic acid, flavone) as well as in response to synthetic chemicals not naturally encountered (cypermethrin, phenobarbital) [21,22].…”

“…Multiple P450 genes exist in a given genome, some of which may function as essential housekeeping genes involved in the biosynthesis of hormones [18,19]; others may act as environmental response genes involved in the biosynthesis of toxic compounds for plant defense or pathogens attack or in the detoxification of naturally-occurring and synthetic xenobiotics [2,17,20]. To address the issue of whether TEs mediate genomic changes in the environmental response P450 genes, we scanned two alleles (one from a laboratory colony, another from a cell line) per each of the six xenobiotic-metabolizing Helicoverpa zea P450 genes, CYP6B8, CYP6B27, CYP9A12v3, CYP9A14, CYP321A1 and CYP321A2 [21][22][23][24][25], for the presence of TE insertions by genome walking and sequence analysis. Twelve novel TEs, including LINEs (long interspersed nuclear elements), SINEs (short interspersed nuclear elements), MITEs (miniature inverted-repeat transposable elements), one fulllength transib-like transposon, and one full-length Tcllike DNA transpson, are identified from their introns, exons or flanking regions.…”

Molecular characterization of two novel deltamethrin‐inducible P450 genes from Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae)

“…Recently, this approach was used to identify two P450 genes (CYP6B1 and CYP6B3) in P. polyxenes induced by and metabolizing furanocoumarins, toxins produced by their host plant (Petersen et al, 2001). Similarly, other P450 genes capable of metabolizing xanthotoxin were characterized in H. zea Sasabe et al, 2004). The effect of xenobiotic exposure on the expression of detoxification genes was investigated by microarraybased approaches in Drosophila.…”

A link between host plant adaptation and pesticide resistance in the polyphagous spider miteTetranychus urticae

“…The "preadaptation hypothesis" for insecticide resistance has been supported by surveys of the literature (11,12) although the comparisons drawn between herbivores and natural enemies or between chewing and sucking herbivores may be confounded by taxonomy, thus calling for other forms of experimental and observational evidence (12). It is now well accepted that herbivore exposure to different plant allelochemicals can affect the toxicity of pesticides (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25). Moreover, metabolic resistance to pesticides is known to commonly rely on the increased expression of one or more genes encoding detoxification enzymes and formal evidence that many of these detoxification enzymes can metabolize both plant chemicals and pesticides is accumulating (26,27).…”