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苹果轮纹病菌(Botryosphaeriaberengrianaf.sppiricola)能在培养基及活体内产生一系列果胶酶:多聚半乳糖醛酸酶(PG)、聚甲基半乳糖醛酸酶(PMG)、多聚半乳糖醛酸反式消除酶(PGTE)和果胶甲基反式消除酶(PMTE)。其中PG和PMG是降解果实胞壁的主要酶类,在整个致病过程中起重要作用。从结果可看出PG活性随着侵染的进展而升高,PMG的作用在侵染前期更大一些,2种果胶酶可能是引起被接种苹果果皮上还原糖变化的重要因素。接种与未接种果实果皮的pH值差异随侵染进程而降低,接种40d后,接种处pH值开始低于健康组织的pH值,这一变化可能造成细胞壁软化而有利于PG和PMG活动。接种后10～20d,PG活性及组织中还原糖的增长速度比其他阶段要快。对侵染点的病原组织学研究进一步表明,病菌产生的各种果胶酶不论是在侵染初期还是后期都是重要的致病物质。
Botryosphaeria berengrianaf sppiricola can produce a series of pectinase in culture medium and in vivo: polygalacturonase (PG), polymethyl galacturonase (PMG), galactooligosaccharides Aldonic trans-elimination enzyme (PGTE) and pectin methyl trans-elimination enzyme (PMTE). Among them, PG and PMG were the main enzymes that degraded the cell wall of fruit and played an important role in the pathogenicity. It can be seen from the results that PG activity increased with the progress of infection and the effect of PMG was greater at the early stage of infection. The two pectinases may be the important factors that cause the change of reducing sugar on the peel of the inoculated apple. The differences of pH value between perfused and uninoculated fruit peels decreased with the progress of infection. After 40 days of inoculation, the pH value of inoculated part began to be lower than that of healthy tissues. This change may cause the cell wall to soften and facilitate the activities of PG and PMG. From 10 to 20 days after inoculation, the activity of PG and the growth of reducing sugars in tissues were faster than other stages. Etiological histological studies of the infection point further indicate that the various pectin enzymes produced by the germs are important pathogenic agents both in the early and late stages of infection.