Abstract：Peroxiredoxins(Prxs)are a superfamily of cysteine-dependent peroxidases that decompose hydrogen peroxide. Among the family, typical 2-cysteine Peroxiredoxins (2-Cys Prxs) are multifunctional proteins. In plant nematode, 2-Cys Prxs play an important role in nematode development in planta or in countering radicals produced by the plant as a defense response to parasitism. In order to understand the effect of low dose of nematicides on 2-Cys Prxs mRNA expression, a novel 2-Cys Prx gene was cloned from Ditylenchus destructor using RT-PCR and RACE techniques, and its mRNA expression of D. destructor treated by low dose(10、1、0.1、0.01、0.001 and 0.0001 μg/mL) nematicides of emanectin benzoate and aldicarb were monitored using Real-time PCR after 24 h. The results showed that the full-length cDNA was 784 bp with an open reading frame (ORF) of 591 bp encoding 196 amino acids residues, named Dd-prx-1(GenBank accession No. JQ609353). The protein had a predicted molecular weight of 21 850.09 D and a hypothetical pI of 6.83. The structure of Dd-Prx-1 genomic DNA include 6 extons and 5 introns. The N-terminal of predicted protein had no apparent signal peptide, but there was one transmembrane domain containing of 23 hydrophilic amino acids. Homology analysis showed that the deduced Dd-PRX-1 protein was highly homologous to the 2-cysteine peroxiredoxin in other nematodes. After treated by low dose emanectin benzoate and aldicarb, the expression levels of Dd-Prx-1 had no significant difference compared with control (P<0.05). The results provide the useful information for further research mechanisms of nematodes response to low dose of nematicides.
