摘要
The novel full length of cytochrome P450 gene has been isolated in insecticideresistant （named CYP6CXlvl） and -susceptible （named CYP6CXlv2） Bemisia tabaci, which was identified as B biotype, in Shangjie, Fujian, China （Sj）. CYP6CX1 （1 940 bp contained a 1 557 bp open reading frame） included conserved domains common to CYP6 members, such as heme-binding motif PFGEGPRFCIA, putative ＂meander＂-binding sequence ETLR and PERF in helix-K, oxygen-binding motif AGLDPV and conserved sequence PEKFNP near the carboxyl end. There were four different replacements of amino acid residues between R and S B. tabaci （Thr300 Ala, Thr354Pro, Arg486His and Ile503Thr）, among which the substitution Ile503Thr was located in the substrate recognition sites region. The mRNA transcription level of CYP6CXlvl was 2.38-fold as high as that of CYP6CXlv2. The results indicated that the CFP6CX1 from the B biotype B. tabaci in Sj was one of the CYP6 members, and enhanced CYP6CX1 expression and substitute of amino acid residues might be involved in the resistance mechanisms in field B. tabaci.
The novel full length of cytochrome P450 gene has been isolated in insecticideresistant （named CYP6CXlvl） and -susceptible （named CYP6CXlv2） Bemisia tabaci, which was identified as B biotype, in Shangjie, Fujian, China （Sj）. CYP6CX1 （1 940 bp contained a 1 557 bp open reading frame） included conserved domains common to CYP6 members, such as heme-binding motif PFGEGPRFCIA, putative ＂meander＂-binding sequence ETLR and PERF in helix-K, oxygen-binding motif AGLDPV and conserved sequence PEKFNP near the carboxyl end. There were four different replacements of amino acid residues between R and S B. tabaci （Thr300 Ala, Thr354Pro, Arg486His and Ile503Thr）, among which the substitution Ile503Thr was located in the substrate recognition sites region. The mRNA transcription level of CYP6CXlvl was 2.38-fold as high as that of CYP6CXlv2. The results indicated that the CFP6CX1 from the B biotype B. tabaci in Sj was one of the CYP6 members, and enhanced CYP6CX1 expression and substitute of amino acid residues might be involved in the resistance mechanisms in field B. tabaci.
