Phosphate-solubilization mechanism and in vitro plant growth promotion activity mediated by Pantoea eucalypti isolated from Lotus tenuis rhizosphere in the Salado River Basin (Argentina)
Phosphate-solubilization mechanism and in vitro plant growth promotion activity mediated by Pantoea eucalypti isolated from Lotus tenuis rhizosphere in the Salado River Basin (Argentina)
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DOI：
10.1111/j.1365-2672.2011.04968.x
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发表时间：
2011-05-01
影响因子：
4
通讯作者：
Ruiz, O. A.
中科院分区：
文献类型：
--
作者：
Castagno, L. N.;Estrella, M. J.;Ruiz, O. A.
目的：分离和表征溶磷菌株从一个受限制的环境，如萨拉多河流域，并评估其溶磷机制，以进一步选择最有前途的菌株，以提高种植和持久性百脉根在最重要的地区，专门用于肉牛productioninArgentina.Methods和Results：50分离株，并通过BOX-PCR分析，17个非冗余菌株被确定。16 S rRNA基因序列分析表明，它们与泛菌属（Pantoea）、欧文氏菌属（Erwinia）、假单胞菌属（Pseudomonas）、根瘤菌属（Rhizobium）和肠杆菌属（Enterobacter）等菌属有亲缘关系。这与通过抗生素耐药性分析获得的聚类一致。对所有菌株进行了溶磷活性测定，并将筛选出的菌株接种到L。纤细的植物最有效的分离物被鉴定为Pantoea euclutti，这是一种新的植物根际促生细菌。结论：本研究中获得的分离物在离体条件下对百脉根具有显著的植物促生活性，其中最好的菌株主要通过诱导葡萄糖酸的分泌和氧化代谢来溶解磷酸盐。这些细菌单独或与固氮微生物组合作为生物接种剂的用途，可能是一种可持续的做法，以促进营养供应的百脉根植物和防止负面的副作用，如富营养化。
Aims:To isolate and characterize phosphate-solubilizing strains from a constrained environment such as the Salado River Basin and to assess their phosphate-solubilizing mechanisms, to further selection of the most promising strains to inoculate and improve the implantation and persistence of Lotus tenuis in the most important area devoted to meat-cow production in Argentina.Methods and Results:Fifty isolates were obtained and through BOX-PCR analysis, 17 non-redundant strains were identified. Subsequently, they were found to be related to Pantoea, Erwinia, Pseudomonas, Rhizobium and Enterobacter genera, via 16S rRNA gene sequence analysis. This was in agreement with the clusters obtained by antibiotic resistance analysis. All isolates were tested for their phosphate-solubilizing activity and selected strains were inoculated onto L. tenuis plants. The most efficient isolate, was identified as Pantoea eucalypti, a novel species in terms of plant growth-promoting rhizobacteria.Conclusions:The isolates obtained in this study showed a significant in vitro plant-growth promoting activity onto Lotus tenuis and the best of them solubilizes phosphate mainly via induction of the metabolism through secretion and oxidation of gluconic acid.Singnificance and Impact of the Study:The use of these bacteria as bioinoculants, alone or in combination with nitrogen-fixing micro-organisms, could be a sustainable practice to facilitate the nutrient supply to Lotus tenuis plants and preventing negative side-effects such as eutrophication.