Department of Soil Science and Agricultural Chemistry, University of Santiago de Compostela, Campus Vida, 15782 Santiago de Compostela, Spain.
Centre for Environmental Sciences, University of Hasselt, Agoralaan Building B, 3590 Diepenbeek, Belgium.
Sci Total Environ. 2017 Mar 1;581-582:676-688. doi: 10.1016/j.scitotenv.2016.12.180. Epub 2017 Jan 6.
Plant growth promoting (PGP) bacterial strains possess different mechanisms to improve plant development under common environmental stresses, and are therefore often used as inoculants in soil phytoremediation processes. The aims of the present work were to study the effects of a collection of plant growth promoting bacterial strains on plant development, antioxidant enzyme activities and nutritional status of Cytisus striatus and/or Lupinus luteus plants a) growing in perlite under non-stress conditions and b) growing in diesel-contaminated soil. For this, two greenhouse experiments were designed. Firstly, C. striatus and L. luteus plants were grown from seeds in perlite, and periodically inoculated with 6 PGP strains, either individually or in pairs. Secondly, L. luteus seedlings were grown in soil samples of the A and B horizons of a Cambisol contaminated with 1.25% (w/w) of diesel and inoculated with best PGP inoculant selected from the first experiment. The results indicated that the PGP strains tested in perlite significantly improved plant growth. Combination treatments provoked better growth of L. luteus than the respective individual strains, while individual inoculation treatments were more effective for C. striatus. L. luteus growth in diesel-contaminated soil was significantly improved in the presence of PGP strains, presenting a 2-fold or higher increase in plant biomass. Inoculants did not provoke significant changes in plant nutritional status, with the exception of a subset of siderophore-producing and P-solubilising bacterial strains that resulted in significantly modification of Fe or P concentrations in leaf tissues. Inoculants did not cause significant changes in enzyme activities in perlite experiments, however they significantly reduced oxidative stress in contaminated soils suggesting an improvement in plant tolerance to diesel. Some strains were applied to non-host plants, indicating a non-specific performance of their plant growth promotion. The use of PGP strains in phytoremediation may help plants to overcome contaminant and other soil stresses, increasing phytoremediation efficiency.
植物促生（PGP）细菌菌株具有不同的机制，可以在常见的环境胁迫下改善植物的发育，因此常被用作土壤植物修复过程中的接种剂。本研究的目的是研究一组植物促生细菌菌株对金雀花和黄花羽扇豆植物发育、抗氧化酶活性和营养状况的影响，这些植物 a）在珍珠岩中生长，无胁迫条件，b）在受柴油污染的土壤中生长。为此，设计了两个温室实验。首先，金雀花和黄花羽扇豆植物从种子在珍珠岩中生长，并定期用 6 株 PGPR 菌株接种，单独或成对接种。其次，将黄花羽扇豆幼苗种植在受污染的土壤样本中，这些土壤样本取自受污染的耕作层（A 层）和淋溶层（B 层），土壤中含有 1.25%（w/w）的柴油，并接种从第一个实验中选择的最佳 PGPR 接种剂。结果表明，在珍珠岩中测试的 PGPR 菌株显著促进了植物的生长。组合处理比各自的单一菌株更能促进黄花羽扇豆的生长，而单一接种处理对金雀花的生长更有效。在 PGPR 菌株的存在下，黄花羽扇豆在受柴油污染的土壤中的生长显著改善，植物生物量增加了 2 倍或更多。接种剂没有引起植物营养状况的显著变化，除了一组产生铁载体和溶解磷的细菌菌株外，它们导致叶片组织中铁或磷浓度发生显著变化。接种剂在珍珠岩实验中没有引起酶活性的显著变化，但它们显著降低了污染土壤中的氧化应激，表明植物对柴油的耐受性提高。一些菌株被应用于非宿主植物，表明它们的植物促生作用具有非特异性。在植物修复中使用 PGPR 菌株可能有助于植物克服污染物和其他土壤胁迫，提高植物修复效率。
