Molecular and Biochemical Studies on Copper Resistance of Plant Pathogenic Bacteria

用硫酸铜和氢氧化铜（可杀得）对5属31种179株植物病原细菌的铜抗性进行了测定。将细菌暴露于琼脂平板（Bacto马铃薯-葡萄糖琼脂）和水溶液形式的这些铜化合物。琼脂法测得的硫酸铜最低抑菌浓度（MIC）比水溶液法高100倍。对硫酸铜的高抗性观察到卡氏假单胞菌（3 mM）、洋葱假单胞菌（4.5mM）、唐菖蒲假单胞菌（4.25mM）、颖壳假单胞菌（3.2mM）、青枯假单胞菌（2.25mM）、丁香假单胞菌致病变种（pv. aceris（2.25 mM）、P.放线菌素（3.0 mM）、P. maclicola（2.0 mM）、P.番茄（2.75 mM）、托氏假单胞菌（2.75 mM）、欧文氏菌（Erwinia chilli pv.）75 mM）、根癌土壤杆菌（2.25 mM）和辣椒黄单胞菌致病变种（Xanthomonascampestris pv.囊泡（1.75 mM）。假单胞菌rRNA Ⅱ组成员对铜的高抗性一致。每个细菌 ...更多信息 M是？??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????抗铜性表现在颖壳疫霉、水稻疫霉等。猕猴桃疫霉P. maculicola和P.番茄被证实为质粒来源。将颖壳疫霉P. glumae（pPgCul）和烟草疫霉pv.放线菌素（pPaCul）是自身传播的。后者的另一个质粒（pPaCu 2）不具有传播性。铜抗性质粒并不总是与高水平的抗性相关。在黑脉病菌P. sytingae pv.例如，还通过质粒确定了石楠的中等铜抗性（MIC 0.8mM），尽管其性质尚未详细阐明。这些抗铜质粒有时携带其他表型特性，如：例如，在一个实施例中，链霉素抗性质粒放线菌素和胞外多糖的合成。在大多数测试的细菌中，观察到对硫酸铜的抗性程度与对氢氧化铜的抗性程度之间的高度相关性。而洋葱疫霉、唐菖蒲疫霉、颖疫霉和丁香疫霉致病变种（P. sytingae pv.）锕系元素对这两种铜化合物的反应行为与其它元素不同。在P.猕猴桃对氢氧化铜的抗性大于对硫酸铜的抗性。洋葱疫霉、唐菖蒲疫霉和颖壳疫霉的相关性正好相反。这些事实表明，植物病原细菌对铜的抗性机制是多样的，即使是对硫酸铜最高MIC的细菌，对氢氧化铜或可杀得的MIC仍在实际喷雾浓度范围内。因此，植物病原细菌对铜化合物的抗性可能不一定意味着这些化合物在控制细菌性植物病害中无效。少

Copper resistance of plant pathogenic bacteria (5 genus, 31 species and 179 strains) was examined with copper sulfate and copper hydroxide (Kocide). The bacteria were exposed to these copper compounds in the from of agar plate (Bacto potato-dextrose agar) and of aqueous solution. The minimum inhibitory concentration (MIC) of copper sulfate obtained by the agar method was one hundred times higher than that by aqueous solution. The high resistance to copper sulfate was observed with P. caryophylli (3mM), P. cepacia (4.5 mM), P. gladioli (4.25 mM), P. glumae (3.2 mM), P. solanacearum (2.25 mM), P. sytingae pv. aceris (2.25 mM), P. syringae pv. actinidiae (3.0 mM), P. syringae pv. maclicola (2.0 mM), P. syringae pv. tomato (2.75 mM), P. tolaasii (2.75 mM), Erwinia chrysanthemi pv. zeae (2.75 mM), Agrobacterium tumefaciens (2.25 mM), and Xanthomonas capmpestris pv. vesicatoria (1.75 mM). The members of rRNA group II of Pseudomonas were consistent in the high copper resistance. Each bacteriu … More m was???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????Copper resistance in P. glumae, P. syringae pv. actinidiae, P. syringae pv. maculicola and P. syringae pv. tomato was confirmed to be plasmid origin. The plasmid of P. glumae (pPgCul) and P. syringae pv. actinidiae (pPaCul) were self-transmissible. Another plasmid of the latter (pPaCu2) was not transmissible. Copper-resistance plasmids did not always associate with high level of resistance. In P. sytingae pv. photiniae, for example, moderate copper resistance (MIC 0.8 mM) was also determined by a plasmid, although its properties have not been elucidated in detail. These copper-resistance plasmids sometimes carried other phenotypic properties e. g., streptomycin resistance in plasmids of P. syringae pv. actinidiae and extracellular polysaccharide synthesis in the plasmid of P. syringae pv. maculicola.In the majority of bacteria tested, high correlation was observed between the degree of resistance to copper sulfate and that to copper hydroxide. However, P. cepacia, P. gladioli, P. glumae and P. sytingae pv. actinidiae were different from others in the behavior to these two copper compounds. In P. syringae pv. actinidiae, the resistance to copper hydroxide was greater than that to copper sulfate. The relationship was just opposite in P. cepacia, P. gladioli and P. glumae. These facts suggested that the diverse mechanisms are involved in copper resistance of plant pathogenic bacteria.Even in bacteria with the highest MIC to copper sulfate, the MIC to copper hydroxide or Kocide was still within the range of concentrations for practical spray. Thus, the resistance to copper copmpounds in plant pathogenic bacteria may not necessarily imply the ineffectiveness of these compounds in control of bacterial plant diseases. Less