Abstract:Using Petri dish method and normal biochemical methods, the mechanism of a novel compound ZJ-2725 was studied under the laboratory condition. The results showed the inhibition of ZJ-2725 on the stem of Abutilon theophrasti could recover when adding three branched chain amino acids valine, leucine, and isoleucine together at 20 mg/L concentration. However, it could not eliminate the inhibition effect absolutely when only adding one of the three branched chain amino acids at the same concentration. In vitro, the inhibition rate on the specific activity of acetolaetate synthase (ALS) increased with the concentration increase of ZJ-2725. The specific activity of ALS increased as the reaction time was prolonged, and the relationship between the specific activity of ALS and the reaction time was coincident with Michaelis-Meten equation. In vivo, ZJ-2725 also inhibited the specific activity of ALS. The results revealed that ZJ-2725 could prevent biosynthesis of the three branched chain amino acids, then restrained the pathway of protein biosynthesis, and hence inhibited the plant growth, indicating that ZJ-2725 was the inhibitor of ALS.