马铃薯干腐病菌侵染过程中切片组织细胞壁降解酶的变化

【目的】探讨干腐病菌(Fusarium sulphureum Schlechlendahl)侵染过程中马铃薯切片组织主要细胞壁降解酶(cell wall degrading enzymes, CWDEs)活性的动态变化。【方法】陇薯3号马铃薯块茎组织切片接种F. sulphureum后，不同培养天数取样测定并比较分析主要CWDEs活性变化。【结果】F. sulphureum侵染的组织均能产生多聚半乳糖醛酸酶(PG)、果胶甲基半乳糖醛酸酶(PMG)、纤维素酶(Cx)、β-葡萄糖苷酶、多聚半乳糖醛酸反式消除酶(PGTE)、果胶甲基反式消除酶(PMTE)、果胶甲基酯酶(PME)、果胶裂解酶(PML)，但PG、PMG、Cx、β-葡萄糖苷酶活性显著高于其它酶。在侵染前期(1-3 d) PMG和Cx出现高峰，PG在后期(4-6 d)活性增高，而β-葡萄糖苷酶在整个侵染过程中活性一直呈上升趋势。【结论】CWDEs是F. sulphureum侵染和扩展过程中主要的致病因子，且各种CWDEs在致病中发挥作用的时期不同。

Changes of Cell Wall Degrading Enzymes in Potato Tuber Tissue Slices Infected by Fusarium sulphureum

【Objective】The dynamic changes of main cell wall degrading enzymes(CWDEs) activities in potato tuber tissue slices infected by Fusarium sulphureum were investigated.【Method】Major CWDEs activities of potato tuber slices tissue(Longshu No.3) inoculated with F.sulphureum were detected and comparatively analyzed during different sampling period.【Result】 A series of CWDEs including polygalacturonase(PG),polymethyl-galacturonase(PMG),carboxymethyl cellulose(Cx),β-glucosidase,polygalacturonic acid trans-eliminase(PGTE),pectin methyl-trans-eliminase(PMTE),pectin methylesterase(PE) and pectate lyase were detected in infected tissue.Whereas PG,PMG,Cx,and β-glucosidase showed higher activities as compared with others.The activity of PMG and Cx kept higher during early infection period(1-3 days after infection),but higher PG activity appeared during later infection period(4-6 days after inoculation),but β-glucosidase showed a rising trend during the enzyme dynamics analysis.【Conclusion】 These findings suggested that CWDEs were the primary pathogenic factors,and different CWDEs might take effect at different infecting periods.