Studies on Effect and its Mechanism of Herbicide Mixture of Cyhalofop-butyl, pyribenzoxim and Pyrazosulfuron-ethyl - II. Effect of Herbicide Mixture on the Activity of ALS, Content of Free Amino Acids and Fatty Acids

Cyhalofop-butyl, Pyribenzoxim 및 Pyrazosulfuron-ethyl의 상호작용효과(相互作用效果) 및 상호작용(相互作用) 기작(機作)에 관(關)하여 - 제(第) 2 보(報) 혼합제초제(混合除草劑) 처리(處理)가 acetolactate synthase 활성(活性) 및 유리(遊離) 아미노산함량(含量)과 지방산함량(脂肪酸含量)에 미치는 영향(影響)

This study was conducted to determine the activity of ALS, content of endogenous free amino acids and fatty acids affected by herbicide mixture of cyhalofop-butyl, pyribenzoxim and pyrazosulfuron-ethyl. $I_{50}$ values (concentration required for 50% inhibition of ALS activity) of pyribenzoxim herbicide on the activity of ALS in Echinochloa crus-galli and Cyperus serotinus in vitro were recorded at 4${\times}$100 nM and 5${\times}$10 nM, respectively, while $I_{50}$ values of pyrazosulfuron against E crus-galli and C. serotinus were 4.5${\times}$10 nM and 4${\times}$10 nM, respectively, and the mixture of two herbicides showed additive effect on ALS activity at the low application rate, and independent effect at the high application rates of two herbicides. The inhibition rates of the three herbicides mixture treatment on the three branch-chain amino acids such as valine, leucine and isoleucine were 74.6%, 66.6% and 57.9% in C. serotinus and 36.6% 51.1% and 48.1% in E. crus-galli, respectively. A little bit higher inhibitory effect on the three branch-chain amino acids in C. serotinus and E. crus-galli seedlings was observed in two herbicide mixture of pyribenzoxim with pyrazosulfuron than three herbicide mixture of cyhalofop with pyribenzoxim and pyrazosulfuron. The interaction among three herbicides showed non-antagonism on the amounts of endogenous free amino acids.

제초제(除草劑) cyhalofop, pyrazosulfuron 및 pyribenzoxim 혼합처리(混合處理)의 상로작용(相互作用) 기작(機作)을 구명(究明)하고자 혼합제초제(混合除草劑)의 처리(處理)에 의한 ALS 활성(活性) 저해효과(沮害效果) 및 유리(遊離) 아미노산 함량변화(含量變化)와 집방산(脂肪酸) 함량변화(含量變化)를 조사한 결과를 요약하면 다음과 같다. 1. In vitro에서 ALS 활성(活性) 저해효과(沮害效果)는 pyribenzoxim의 $I_{50}$은 물피와 너도방동사니에서 각각(各各) 4${\times}$100 nM과 5${\times}$100 nM였으며, pyrazosulfuron의 $I_{50}$은 각각 4.5${\times}$10 nM과 4${\times}$10nM로 두 제초제(除草劑) 혼합처리시(混合處理時) ALS 활성(活性) 저해효과(沮害效果)는 저농도처리(低濃度處理)에서 상가적작용(相加的作用), 고농도처리(高濃度處理)에서는 독립작용(獨立作用)을 보였다. 2. 3종류(種類) 제초제(除草劑)(cyhalofop+pyribenzoxim+pyrazosulfuron 100+10+10 g ai/ha) 혼합처리(混合處理)에 의해 너도방동사니와 물피의 valine, leucine 및 isoleucine의 함량(含量)은 58~75%, 37%, 51%씩 각각(各各) 감소(減少)하여 저해정도가 물피보다 너도방동사니에서 더 컸으며, 그 경향은 cyhalofop을 혼합(混合)하지 않은 2종류(種類)의 혼합제초제(混合除草劑) 처리(處理)에서 다소 높았으나 초종(草種) 및 제초제(除草劑) 종류(種類)에 따라 상이(相異)하였다. 3. 3종(種)의 제초제처리(除草劑處理)에 의해 총(總) 지방산(脂肪酸) 함량(含量) 및 지방산(脂肪酸) 종류별(種類別) 함량(含量)이 모두 감소(減少)되었으나 지방산(脂肪酸) 함량(含量)에 대한 3종(種) 제초제간(除草劑間)의 길항작용(拮抗作用)은 없었다.