Sainsbury Laboratory, John Innes Institute, Colney Lane, Norwich NR4 7UH, United Kingdom.
Plant Physiol. 1990 May;93(1):238-43. doi: 10.1104/pp.93.1.238.
Inoculation of mature leaves of turnip (Brassica campestris) with the incompatible Xanthomonas campestris pv vitians resulted in the induction of beta-1,3-glucanase and chitinase/lysozyme (CHL) activity. No increase in the basal activity of beta-1,3-glucanase was observed after inoculation of leaves with heat- or rifampicin-killed X. c. vitians, Escherichia coli, or sterile water. Inoculation with the compatible X. campestris pv campestris resulted in a slower induction of glucanase than that seen with X. c. vitians. In contrast, all bacteria caused an induction of CHL activity. One major beta-1,3-glucanase (molecular mass 36.5 kilodaltons, isoelectric point [pl] ~8.5) was purified from both inoculated and untreated leaves by ion-exchange chromatography. The enzyme degraded laminarin by an endo-glycolytic mechanism. Two major CHL isozymes (CHL 1 and CHL 2, molecular mass 30 kilodaltons and pl 9.4 and 10.2, respectively) were purified from X. c. vitians inoculated leaves by affinity chromatography on a chitin column followed by ion-exchange chromatography. Both enzymes degraded chitin by an endo-glycolytic mechanism although the ratio of lysozyme to chitinase specific activities for CHL 1 and CHL2 were different. The induction of CHL 1 was associated with the hypersensitive reaction caused by X. c. vitians whereas all other treatments induced largely CHL 2.
将芜菁成熟叶片接种不亲和的野油菜黄单胞菌 pv 致病变种会诱导β-1,3-葡聚糖酶和几丁质酶/溶菌酶 (CHL) 活性。用热或利福平杀死的野油菜黄单胞菌 pv 致病变种、大肠杆菌或无菌水接种叶片后，β-1,3-葡聚糖酶的基础活性没有增加。与野油菜黄单胞菌 pv 致病变种相比，接种亲和的野油菜黄单胞菌 pv 野油菜会导致葡聚糖酶的诱导速度较慢。相比之下，所有细菌都会诱导 CHL 活性。一种主要的β-1,3-葡聚糖酶（分子量 36.5 千道尔顿，等电点 [pl]~8.5）通过离子交换层析从接种和未处理的叶片中纯化。该酶通过内糖苷酶机制降解几丁质。两种主要的 CHL 同工酶（CHL 1 和 CHL 2，分子量 30 千道尔顿，pl 分别为 9.4 和 10.2）通过亲和层析在几丁质柱上从接种野油菜黄单胞菌 pv 致病变种的叶片中纯化。两种酶都通过内糖苷酶机制降解几丁质，尽管 CHL 1 和 CHL2 的溶菌酶比几丁质酶比活力的比值不同。CHL 1 的诱导与野油菜黄单胞菌 pv 致病变种引起的过敏反应有关，而其他所有处理均主要诱导 CHL 2。
