苯并噻唑衍生物亚磷酸盐对禾谷镰刀菌的作用机理初探

Preliminary Study on Mechanism of Action of Benzothiazole-phosphites to Fusarium graminearum

为了寻找具有更高杀菌活性的化合物，将苯并噻唑衍生物与亚磷酸反应，得到了4个苯并噻唑衍生物的亚磷酸盐，其结构均经IR、NMR及元素分析确证。采用功丝生长速率法测定了4个亚磷酸盐对禾谷镰刀菌Fusarium graminearum的离体抑菌作用，观察了药剂对菌丝形态的影响，并初步研究了其作用机制。结果表明．4个亚磷酸盐对禾谷镰刀菌均有较好的抑制效果，其抑制中浓度（EC50）在15．2～36．1μg／mL之间。以100μg／mL的2-氨基-6-甲氧基苯并噻唑亚磷酸盐（D）处理3d后，菌丝表现畸形、膨肿，8d后出现干瘪、塌陷，外壁模糊、粗糙；分别以300μg／mL的4个亚磷酸盐处理后12h内，菌体内还原糖含量明显降低，几丁质酶活性显著升高，可溶性蛋白和N-乙酰葡萄糖胺含量短期内略有上升随后下降。

Four novel benzothiazole-phosphites were prepared from benzothiazole derivatives. Their structures were confirmed by IR, NMR and elemental analysis. The inhibitory effects and mechanisms of action of four benzothiazole-phosphites to Fusarium graminearum in vitro were studied with the mycelial growth rate method. The results showed that four salts had high inhibitory effect on the growth of Fusarium graminearum,with the value of ECso ranged from 15.2 to 36.1 p,g/mL. After F. graminearum was treated with 100 p,g/mL of 2-amino-6-methoxybenzothiazole-phosphite （D）, the hyphal morphology was observed abnormal and swollen after 3 days. After 8 days, part of the hypha and ramification was shriveled and collapsed, and the surface of mycelium was blurred and unshaped. After treatments with four salts at 300 p,g/mL within 12 h , the mycelial reducing sugar content declined obviously and chitinase activity increased significantly. And the soluble protein and D-GlcNAc content increased in the short time and decreased subsequently.