Characterization of plant growth promoting traits of bacterial isolates from the rhizosphere of barley (Hordeum vulgare L.) and tomato (Solanum lycopersicon L.) grown under Fe sufficiency and deficiency.
Plant Growth Promoting Bacteria (PGPB) are considered a promising approach to replace the conventional agricultural practices, since they have been shown to affect plant nutrient-acquisition processes by influencing nutrient availability in the rhizosphere and/or those biochemical processes determining the uptake at root level of nitrogen (N), phosphorus (P), and iron (Fe), that represent the major constraints for crop productivity worldwide. We have isolated novel bacterial strains from the rhizosphere of barley (Hordeum vulgare L.) and tomato (Solanum lycopersicon L.) plants, previously grown in hydroponic solution (either Fe deficient or Fe sufficient) and subsequently transferred onto an agricultural calcareous soil. PGPB have been identified by molecular tools and characterized for their capacity to produce siderophores and indole-3-acetic acid (IAA), and to solubilize phosphate. Selected bacterial isolates, showing contemporarily high levels of the three activities investigated, were finally tested for their capacity to induce Fe reduction in cucumber roots two isolates, from barley and tomato plants under Fe deficiency, significantly increased the root Fe-chelate reductase activity; interestingly, another isolate enhanced the reduction of Fe-chelate reductase activity in cucumber plant roots, although grown under Fe sufficiency.
Department of Soil, Plant and Food Sciences, University of Bari "Aldo Moro", Via Amendola 164/a, 70125 Bari, Italy.
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Scagliola
Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100 Bolzano, Italy.
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Pii
Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100 Bolzano, Italy.
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Mimmo
Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100 Bolzano, Italy.
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Cesco
Department of Soil, Plant and Food Sciences, University of Bari "Aldo Moro", Via Amendola 164/a, 70125 Bari, Italy.
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Ricciuti
Department of Soil, Plant and Food Sciences, University of Bari "Aldo Moro", Via Amendola 164/a, 70125 Bari, Italy. Electronic address: carmine.crecchio@uniba.it.
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Crecchio
D001419:Bacteria / Q000187:drug effects / Q000302:isolation & purification*; D004275:DNA, Ribosomal / Q000235:genetics; D038181:FMN Reductase / Q000378:metabolism; D001467:Hordeum / Q000254:growth & development / Q000382:microbiology*; D007501:Iron / Q000494:pharmacology*; D000090463:Iron Deficiencies; D018551:Solanum lycopersicum / Q000254:growth & development*; D010802:Phylogeny; D058441:Rhizosphere; D032322:Solanum / Q000254:growth & development / Q000382:microbiology*
D004275:DNA, Ribosomal; D007501:Iron; D038181:FMN Reductase; C023903:ferric citrate iron reductase
Fe-chelate reductase; Indole 3-acetic acid production; Phosphate solubilization; Plant growth promoting bacteria; Siderophores production