The Enhancement of Cytochrome P-450 Mediated Aryl Hydroxylation of Bentazon in Rice Microsomes

벼에서 Bentazon 히드록시화반응에 관련된 Cytochrome P-450 활성(活性) 증진(增進)에 관한 연구(硏究)

Bentazon 6-hydroxylase (B6H) and cinnamic acid 4-hydroxylase (CA4H) activities were determined in rice (Oryza sativa L.) microsomes to study methods of enhancing cytochrome P-450 mediated aryl hydroxylation of bentazon by hydoxylase inducing compounds. Pretreating rice seeds with 1,8-naphthalic anhydride at 0.5-2% and fenclorim at 5 and 10 ${\mu}M$ increased B6H and CA4H activities. Treatments of rice seedling with ethanol 2.5% enhanced B6H and CA4H activities, and with phenobarbital at 12 mM enhanced B6H activity, and CA4H activity was enhanced at 2 mM. B6H activity was synergistically enhanced by combined treatments of ethanol 2.5 or 5% and phenobarbital 8 or 12mM and also that of 1,8-naphthalic anhydride 0.5 or 1% and phenobarbital 8 or 12 mM, but CA4H activity was decreased by combined treatment. Five-day-old rice seedlings showed higher B6H and CA4H activities which decreased with seedling age.

Bentazon이 첫 분해대사물질인 6-hydroxy bentazon으로 변화하는데 관련하는 cytochrome P-450 활성을 증진시키는 방법을 모색하기 위하여 벼 microsome에서 hydroxylase 효소 유기물질을 처리하여 bentazon 6-hydroxylase(B6H)와 식물에서 흔히 볼 수 있는 cinnamic acid 4-hydroxylase(CA4H) 효소를 대조하여 효소활성을 검정하였다. 1,8-naphthalic anhydride 0.5-2% 농도를 벼 종자에 분의처리하거나 fenclorim 5, 10${\mu}M$을 벼종자에 침지처리함에 따라 B6H와 CA4H 효소 활성이 증대되었다. Ethanol 2.5%를 벼 유묘에 처리함으로써 B6H와 CA4H 활성이 증대되었으며, phenobarbital 12mM 처리에서 B6H 활성이 증대되었고 phenobarbital 2mM 처리에서는 CA4H 활성이 증대되었다. B6H 효소활성은 ethanol 2.5, 5%와 phenobarbital 8, 12mM 혼합 처리 또는 1,8-naphthalic anhydride 0.5, 1%와 phenobarbital 8, 12mM 혼합처리에서 상승적으로 증가하였으며, CA4H 효소는 혼합처리에 의하여 활성이 저하되었다. 한편 벼 5 일묘에서는 B6H와 CA4H 활성 이 가장 높았으며 묘령이 진전될수록 효소활성은 현저히 감소되는 경향을 나타냈다.