花生种子胰蛋白酶抑制剂与抗黄曲霉侵染的关系

Relationship of Trypsin Inhibitor in Peanut Seed and Resistance to Aspergillus flavus Invasion

通过丙酮分级沉淀和 DEAE- Sephadex A5 0离子交换柱 ,从花生种子醋酸提取液中分离纯化出具有胰蛋白酶抑制剂活性的物质。SDS- PAGE电泳图谱显示 ,纯化的胰蛋白酶抑制剂是以二聚体形式存在 ,分子量分别为 17.1和10 .3k Da,纯化的胰蛋白酶抑制剂在体外能显著地抑制黄曲霉 (Aspergillusflavus)孢子的萌发和菌丝的生长 ,表明胰蛋白酶抑制剂是花生种子抗黄曲霉的有效成分。种子胰蛋白酶抑制剂含量的多少、活性的高低与品种抗黄曲霉侵染的能力有关。 5个抗性品种胰蛋白酶抑制剂的含量和活性均高于感病品种 ,且抗性品种胰蛋白酶抑制剂粗提液体外抑菌效果也较感病品种显著 ,表明花生种子胰蛋白酶抑制剂含量和活性可作为花生抗黄曲霉侵染的标记性状之一。

A trypsin inhibitor in peanut seeds was purified by acetone fractionation, followed by passing through DEAE-Sephadex A50 ion-exchange column. The purified inhibitor consisted of two subunits with molecular weight of 10.3 and 17 kDa respectively. The inhibition of germination and hypha growth of Aspergillus flavus was observed in protein concentration 10 μg on Czapek medium. The content and activity of trypsin inhibitor in peanut seeds were correlated with it′s resistance to Aspergillus flavus invasion and aflatoxin producing. The content and activity of trypsin inhibitor in resistant genotypes were significantly higher than that in susceptible genotypes.