Ectomycorrhizal symbiosis affects functional diversity of rhizosphere fluorescent pseudomonads
Ectomycorrhizal symbiosis affects functional diversity of rhizosphere fluorescent pseudomonads
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DOI：
10.1111/j.1469-8137.2004.01212.x
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发表时间：
2005-01-01
期刊：
影响因子：
9.4
通讯作者：
Garbaye, J
中科院分区：
文献类型：
--
作者：
Frey-Klett, P;Chavatte, M;Garbaye, J
从道格拉斯冷杉（Pseudostuga menziesii）幼苗-双色蜡蚧（Laccaria bicolor S238 N）的苗圃土壤、外生菌根和外生菌根中分离到60株荧光假单胞菌（P. fluorescens）。它们的特征在于在体外与以下标准：ARP 4，磷酸盐溶解，铁载体，HCN和AIA的生产，N-2-固定和抗生素合成的基因，在体外对抗一系列的植物病原真菌和外生菌根真菌，对道格拉斯冷杉-L的影响。对于大多数标准，我们证明外生菌根圈显著地构建了荧光假单胞菌种群，并选择了潜在的有利于共生和植物的菌株。这促使我们提出外生菌根共生是一种真正的微生物复合体，其中发生了多营养相互作用。此外，它强调了这样一个事实，即这种共生除了其已知的直接积极影响外，还通过其对细菌群落的选择压力对植物生长产生间接的积极影响。
Here we characterized the effect of the ectomycorrhizal symbiosis on the genotypic and functional diversity of soil Pseudomonas fluorescens populations and analysed its possible consequences in terms of plant nutrition, development and health.Sixty strains of P. fluorescens were isolated from the bulk soil of a forest nursery, the ectomycorrhizosphere and the ectomycorrhizas of the Douglas fir (Pseudostuga menziesii) seedlings-Laccaria bicolor S238N. They were characterized in vitro with the following criteria: ARDRA, phosphate solubilization, siderophore, HCN and AIA production, genes of N-2-fixation and antibiotic synthesis, in vitro confrontation with a range of phytopathogenic and ectomycorrhizal fungi, effect on the Douglas fir-L. bicolor symbiosis.For most of these criteria, we demonstrated that the ectomycorrhizosphere significantly structures the P. fluorescens populations and selects strains potentially beneficial to the symbiosis and to the plant.This prompts us to propose the ectomycorrhizal symbiosis as a true microbial complex where multitrophic interactions take place. Moreover it underlines the fact that this symbiosis has an indirect positive effect on plant growth, via its selective pressure on bacterial communities, in addition to its known direct positive effect.