Different Physiological Activity of Selected Rice Cultivars to Diphenylether Herbicide, Oxyfluorfen - III. Differential Protoporphyrinogen Oxidase(Protox) Activity and Protoporphyrinogen IX(PPIX) Accumulation

Oxyfluorfen에 대한 내성(耐性) 및 감수성(感受性) 벼품종(品種)의 생리활성(生理活性) 기구 (機構) - III. Protoporphyrinogen oxidase(Protox)활성(活性)과 Protoporphyrinogen IX(PPIX) 축적(蓄積)

This study was conducted to investigate the inhibition of protox activity and the PPIX accumulation of the oxyfluorfen-tolerant and-susceptible rice cultivars with barnyardgrass, a typical susceptible weed in accordance by oxyfluorfen treatment. The susceptible rice cultivars and barnyardgrass showed more inhibition of protox activity due to the treatment of oxyfluorfen than the tolerant rice cultivars. Especially in the concentration at $10^{-6}$M treatment, protox activity of the susceptible rice cultivars and barnyardgrass were the completely inhibited but the tolerant rice cultivars kept 32~59% of activity compared to the control. As the treatment concentration increased, the content of PPIX accumulation increased and it increased untill four hours of light exposure but it tended to decrease these after. The content of PPIX accumulation by the treatment of oxyfluorfen was more pronounced in the light condition than in the dark. Under the light and dark conditions, the susceptible rice cultivars and barnyardgrass showed more PPIX accumulation than the tolerant rice cultivate. Especialiy the susceptible barnyardgrass had more than the rice. With the treatment of GC and DA, tetrapyrrole biosynthesis inhibitor, the herbicidal activity by oxyfluorfen was inhibited, and the susceptible rice cultivars and barnyardgrass tended to have less effective than the tolerant rice cultivars and the content of chlorophyll or PPS accumulation tended to be similar.

Oxyfluorfen 내성(耐性) 및 감수성(感受性) 벼품종(品種)과 감수성 피를 공시하여 oxyfluorfen 처리에 의한 protox 활성저해(活性沮害), PPIX 축적량(蓄積量)과 tetrapyrro1e 생합성(生合性) 억제제(抑制齊) 처리에 의한 oxyfluorfen의 제초활성(除草活性) 억제효과를 조사하였다. 1. Oxyfluorfen 처리에 따른 protox 활성저해(活性沮害)는 내성(耐性) 벼품종(品種)들보다 감수성(感受性) 벼품종(品種)들과 피에서 컸다. 특히,$10^{-6}$ 처리 이상의 농도에서 감수성(感受性) 벼품종(品種)들과 피에서는 완전히 억제되었으나, 내성(耐性) 품종(品種)들에서는 무처리에 대비하여 32~59%의 활성(活性)을 유지하였다. 2. 처리농도가 증가할수록 PPIX의 축적량(蓄積量)은 증가하였고, 광노출 4시간까지는 증가하나 그 이후에는 감소하는 경향이었다. 3. Oxyfluorfen 처리에 의한 PPIX 축적량(蓄積量)은 암조건(暗條件)에서보다 광조건(光條件)에서 많았다. 광 암조건(光 暗條件)에서 감수성(感受性) 벼품종(品種)들과 피는 내성(耐性) 벼품종(品種)들에 비하여 PPIX 축적량(蓄積量)이 많았다. 특히, 감수성(感受性)인 피는 PPIX 축적량(蓄積量)이 벼품종(品種)에 비해 많았다. 4. Tetrapyrrole 생합성(生合性) 억제제(抑制齊)인 GC와 DA를 처리하면 oxyfluorfen에 의한 제초활성(除草活性)은 억제되었으며, 내성(耐性) 벼품종(品種)보다는 감수성(感受性) 벼품종(品種)이나 피에서 그 효과가 떨어지는 경향으로서 엽록소 함량이나 PPIX 축적량(蓄積量)에서도 동일한 경향을 나타내었다.