草酸青霉BZH-2002果胶酶系的纯化及其诱导抗病作用

Purification and Induced Resistance of Pectinases from Penicillium oxalicum BZH-2002

采用超滤浓缩、亲和层析、阳离子交换柱层析、SephadexG-100凝胶过滤层析等步骤,由草酸青霉菌果胶酶发酵液最终分离得到3个电泳纯的内切聚半乳糖醛酸酶主要组分P-1、P-2和P-3.经SDS-聚丙烯酰胺凝胶电泳测得各组分的分子量(Mr)均为41×103.上述果胶酶组分稀释成不同浓度后分别喷雾处理供试黄瓜,表明3个组分均能不程度地诱导黄瓜对黑星病抗性的提高,在酶活力200UmL-1条件下,3个组分的诱导效果分别为35.18%、57.11%和38.83%,而且3个组分在试验浓度下对病菌孢子萌发和芽管生长均没有影响.

Three components Of endo-polygalacturonases were separated and purified by ultra-filtration and concentration, affinity adsorption chromatography, CM-Cellulose （CM-52） column chromatography and Sephadex G-100 gel filtration chromatography from the crude pectinase extract of Penicillium oxalicum BZH-2002. The molecular weight of each component was characterized by SDS- PAGE, indicating it was the same of 41 ×10^2. The induced resistance to Cladosporium cucumerinum in etiolated cucumber seedlings was evaluated with the purified peetinases above. The results indicated that the 3 components of pectinases exhibited different degrees of increased resistance to the disease. The induced resistance efficieneies of peetinases were respectively 35.18%, 57.11% and 38.83% at the concentration of 200 U mL^-1. No inhibitory activity was observed on conidial germination and germ-tube growth of C. cucumerinum at various concentrations of the 3 pectinases （20 - 200 U mL^-1 ）. Fig 3, Tab 3, Ref 20