Influence of an arbuscular mycorrhizal fungus on Pseudomonas fluorescens DF57 in rhizosphere and hyphosphere soil
Influence of an arbuscular mycorrhizal fungus on Pseudomonas fluorescens DF57 in rhizosphere and hyphosphere soil
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DOI：
10.1046/j.1469-8137.1999.00374.x
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发表时间：
1999-04-01
期刊：
影响因子：
9.4
通讯作者：
Jakobsen, I
中科院分区：
文献类型：
--
作者：
Ravnskov, S;Nybroe, O;Jakobsen, I
研究了根内球囊霉（BEG 87）对荧光假单胞菌（PseudomonasfluorescensDF 57）在根际和根际土壤中的影响。黄瓜（Cucumis sativus，Aminex，F-1 hybrid）与丛枝菌根真菌G.根内聚氯乙烯管，由一个中央根室和两个侧根无室。使用荧光假单胞菌DF 57的两种Tn 5-luxAB标记的菌株。将在磷酸盐饥饿诱导基因座中插入Tn 5：：luxAB的菌株DF 57-P2用作磷酸盐饥饿报告基因。携带组成型表达的luxAB融合体的另一种lux标记的菌株DF 57 - 40 E7用作菌株DF 57-P2的对照，并用于测量荧光假单胞菌DF 57的代谢活性。将携带组成型表达gfp基因的荧光假单胞菌DF 57菌株用于研究细菌和菌丝之间的附着。G.根际荧光假单胞菌DF 57的可培养性显著降低，而荧光假单胞菌DF 57的总数量仅在根际土壤中降低。G.荧光假单胞菌DF 57在48 h后的代谢活性不受真菌的影响。荧光假单胞菌DF 57不粘附G.根内菌丝，不能利用菌丝作为碳基质。G.研究了根际基质对荧光假单胞菌DF 57在土壤中可培养性和数量的影响。
The influence of Glomus intraradices (BEG87) on Pseudomonas fluorescens DF57 in hyphosphere and rhizosphere soil was examined. Cucumis sativus (Aminex, F-1 hybrid) was grown in symbiosis with the arbuscular mycorrhizal fungus G. intraradices in PVC tubes, consisting of a central root compartment and two lateral root-free compartments. Two Tn5-luxAB-marked strains of P. fluorescens DF57 were used. Strain DF57-P2, which has an insertion of Tn5:: luxAB in a phosphate starvation-inducible locus, was used as a phosphate starvation reporter. Another lux-tagged strain DF57-40E7, which carries a constitutively expressed luxAB fusion, was used as control for strain DF57-P2 and for measuring the metabolic activity of P. fluorescens DF57. A strain of P. fluorescens DF57, which carries a constitutively expressed gfp gene, was used in studies of attachment between the bacteria and the hyphae. G. intraradices decreased the culturability of P. fluorescens DF57 significantly, both in rhizosphere and hyphosphere soil, whereas the total number of P. fluorescens DF57 measured by immunofluorescence microscopy was decreased in hyphosphere soil only. G. intraradices did not induce a phosphorus starvation response in P. fluorescens DF57, and the metabolic activity of the bacteria was not affected by the fungus after 48 h. P. fluorescens DF57 did not attach to G. intraradices hyphae and was not able to use the hyphae as carbon substrate. The negative effect of G. intraradices on culturability and on number of P. fluorescens DF57 in hyphosphere soil is discussed.