농약 환경 : Paraquat 저항성 망초의 protective 효소

The resistance of Cornyza bonariensis to herbicide paraquat was investigated by evaluating the activities of three enzymes concerning in scavenging paraquat-generated toxic oxygen species such as superoxide radical and hydrogen peroxide in resistant and susceptible biotypes. Conyza bonariensis inhabited in cultivated area was more tolerant to paraquat than that of uncultivated area. This is the first report that a biotype of Cornyza bonariensis has appeared in an area with repeated paraquat treatments of Korea. Superoxide dismutase activity of resistant biotype was 20% higher as 150 than that of susceptible biotype. Ascorbate peroxidase activity of resistant biotype was 44% higher than that of susceptible biotype. Glutathione reductase activity of resistant biotype was 64% higher than that of susceptible biotype. It can be concluded from above results that the resistance of Conyza bonariensis to paraquat depends partially on the toxic oxygen species-scavenging efficiency of protective multienzymatic system which is composed of three enzymes, superoxide dismutase, ascorbate peroxidase, and glutathione reductase.