氯磺隆和苯磺隆对玉米乙酰乳酸合成酶抑制作用的研究

Study on Enzymatic Inhibition of Acetolactate Synthase from Maize (Zea mays L. ) by Chlorsulfuron and Tribenuron-methyl

用玉米沙培主根长度法测定了玉米品种农大 3138和农大 10 8对氯磺隆和苯磺隆的相对敏感性。结果表明 ,农大 3138耐药能力比农大 10 8强 ,氯磺隆对玉米生长的影响比苯磺隆大。有关玉米离体乙酰乳酸合成酶(ALS)的研究结果表明 ,氯磺隆和苯磺隆对两种玉米离体ALS酶具有强烈的抑制作用 ,是玉米ALS酶的非竞争性抑制剂 ,氯磺隆对两种玉米ALS酶的抑制作用强于苯磺隆。低浓度的氯磺隆和苯磺隆对活体ALS酶无抑制作用 ,高浓度下才抑制活体ALS酶的活性。

The relative sensitivity of maize (Zea mays L.) varieties Nongda108 and Nongda3138 to sulfonylurea herbicide chlorsulfuron and tribenuron methyl was studied by using maize main root length in sand culture. Results showed that Nongda3138 had higher tolerance to chlorsulfuron and tribenuron methyl than Nongda108. Chlorsulfuron had stronger growth inhibitory effect on maize varieties Nongda108 and Nongda3138 than tribenuron methyl. Study on target enzyme of sulfonylurea herbicide acetolactate synthase (ALS) showed that chlorsulfuron and tribenuron methyl inhibited ALS in vitro violently and they were non competitive inhibitors to ALS. At the same concentration of inhibitors, chlorsulfuron had stronger inhibitory effect on ALS activity than tribenuron methyl. Lower level of chlorsulfuron and tribenuron methyl had no inhibitory effect on ALS activity in vivo, and the inhibitory effect on ALS activity only occurred in the condition of high concentration of chlorsulfuron and tribenuron methyl in vivo.