CATALASE AND SUPEROXIDE-DISMUTASE OF ROOT-COLONIZING SAPROPHYTIC FLUORESCENT PSEUDOMONADS
CATALASE AND SUPEROXIDE-DISMUTASE OF ROOT-COLONIZING SAPROPHYTIC FLUORESCENT PSEUDOMONADS
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DOI：
10.1128/aem.56.11.3576-3582.1990
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发表时间：
1990-11-01
影响因子：
4.4
通讯作者：
ANDERSON, AJ
中科院分区：
文献类型：
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作者：
KATSUWON, J;ANDERSON, AJ
恶臭假单胞菌 (Pseudomonas putida-P) 的根定植、腐生荧光假单胞菌。荧光菌组在富含蔗糖和氨基酸的培养基上生长期间表达相似水平的过氧化氢酶和超氧化物歧化酶活性。在这些细菌在从根表面清洗的成分上生长的过程中，观察到过氧化氢酶的比活性增加，但超氧化物歧化酶的比活性没有增加。在这些细菌与完整豆根接触的过程中，两种酶的比活性也受到调节。将细胞接种到完整的豆根上后 10 分钟，迅速观察到超氧化物歧化酶增加和过氧化氢酶活性降低。过氧化氢酶比活性随着时间的推移而增加，在 12 小时达到峰值，然后下降。到 48 小时，细胞表现出较低的过氧化氢酶，但保持较高的超氧化物歧化酶比活性。具有低比活性和高超氧化物歧化酶活性的过氧化氢酶也存在于从施用到种子的接种物定殖的7日龄根获得的细胞提取物中。与在丰富培养基上生长的细胞相比，根接触细胞的超氧化物歧化酶的比活性大约高四倍，而过氧化氢酶的比活性降低了大约五倍。在细菌在根表面成分上生长以及细胞暴露于完整豆根1小时期间，检测到单一过氧化氢酶同工酶A和超氧化物歧化酶同工酶1的一种同工酶。暴露于完整豆根 12 小时后，从细菌中检测到了另一种过氧化氢酶，即同工酶 B。过氧化氢酶同工酶A和超氧化物歧化酶同工酶1位于恶臭假单胞菌的细胞质中，过氧化氢酶带B位于恶臭假单胞菌的膜上。
Root-colonizing, saprophytic fluorescent pseudomonads of the Pseudomonas putida-P. fluorescens group express similar levels of catalase and superoxide dismutase activities during growth on a sucrose- and amino acid-rich medium. Increased specific activities of catalase but not superoxide dismutase were observed during growth of these bacteria on components washed from root surfaces. The specific activities of both enzymes were also regulated during contact of these bacteria with intact bean roots. Increased superoxide dismutase and decreased catalase activities were observed rapidly, by 10 min upon inoculation of cells onto intact bean roots. Catalase specific activity increased with time to peak at 12 h before declining. By 48 h, the cells displayed this low catalase but maintained high superoxide dismutase specific activities. Catalase with a low specific activity and a high superoxide dismutase activity also were present in extracts of cells obtained from 7-day-old roots colonized from inoculum applied to seed. This specific activity of superoxide dismutase of root-contacted cells was about fourfold-higher in comparison to cells grown on rich medium, whereas the specific activity for catalase was reduced about fivefold. A single catalase isozyme A, and one isozyme of superoxide dismutase, isozyme 1, were detected during growth of the bacteria on root surface components and during exposure of cells to intact bean roots for 1 h. An additional catalase, isozyme B, was detected from bacteria after exposure to the intact bean roots for 12 h. Catalase isozyme A and superoxide dismutase isozyme 1 were located in the cytoplasm and catalase band B was located in the membrane of P. putida.