A novel oxidant fumigation (NOF) is a commercial bleaching and disinfection agent. Recent study indicates its insecticidal activity. However, its exact mode of action to kill insects is not known. This study sets up a hypothesis that reactive oxygen species released from NOF is a main factor to kill insects. Plodia interpunctella is a lepidopteran insect pest infesting various stored grains. Both larvae and adults were susceptive to NOF. To test the hypothesis, we needed to identify antioxidant genes in P. interpunctella. Superoxide dismutase (SOD) and thioredoxin-peroxidase (Trx) were identified from P. interpunctella EST library using ortholog sequences of Bombyx mori. Both SOD and Trx were expressed in larvae of P. interpunctella expecially against oxidative stress induced by bacterial challenge. The bacterial challenge also induced some heat shock protein (HSP) genes. Similarly, different doses of NOF significantly induced both SOD and Trx genes. There results suggest that NOF at sublethal doses releases reactive oxygen species, which may be detoxified by the antioxidant activities of SOD and Trx of P. interpunctella.

• Jiyeong Park(Department of Bioresource Sciences, Andong National University)
• Hyuk Kwon(Department of Life Sciences and Biotechnology, Korea University)
• Jahyun Na(Institute of Life Science and Natural Resources, Korea University)
• Yongshik Chun(Institute of Life Science and Natural Resources, Korea University)
• Wook Kim(Department of Life Sciences and Biotechnology, Korea University)
• Yonggyun Kim(Department of Bioresource Sciences, Andong National University)