Plant growth promoting bacteria mitigates salt stress during Handroanthus impetiginosus in vitro rooting

Salinity is one of main abiotic stresses that causes adverse effects on plant growth and affects millions hectares around the world. Variability physical chemical properties soils has made field experiments notoriously difficult to evaluate. Plant tissue culture been used as a model system study physiological responses induced by salinity. The aim this work was evaluate tolerance salinity Handroanthus impetiginosus ‘pink lapacho’ effect inoculation with growth-promoting bacteria previously isolated from adult plants. Shoots for 3 days in half-strength Murashige Skoog medium 30 μM indole butyric acid were then transferred auxin-free medium, supplemented 0, 40, 80 or 160 mM NaCl inoculated not 108 cfu Bacillus sp. L15 Sphingobacterium L22. At end (40 days), 50% Inhibitory Concentration 50 (IC50) determined regression curves constructed rooting percentages. Bacterization L22 strains displaced IC50 higher concentrations (147 mM, respectively) relative controls (109 mM). Furthermore, improved biometric parameters index (BPI) at 40 NaCl. Finally, bacterization concentration modified proline, phenolics chlorophylls contents during first 15 culture. Bacteria also mitigated anatomical alterations produced salt stress. In conclusion, tested promoted vitro alleviated negative stress H. impetiginosus. promotes under conditions improving percentages, modifying biochemical mitigating sal