| Abstract |
Some rhizobacteria were isolated, that have copper resistance
and can confer copper resistance to plants allowing growth
under copper stress. Isolated strains Pseudomonas veronii MS1
and P. migulae MS2 produced 0.13 and 0.26 mmol/ml of
siderophore, that is a metal-chelating agent, and also showed
64.6 and 77.9% of biosorption ability for Cu in 20 mg/L Cu
solution, respectively. Copper can catalyze a formation of
harmful free radicals, which may cause oxidative stress in
organisms. Removal activity of 1,1-diphenyl-2-picryl hydrazyl
radical and antioxidant capacity of strains MS1 and MS2
increased up to 82.6 and 78.1%, respectively compared to those
of control at 24 h of incubation. They exhibited 7.10 and 6.42
μmol α-ketobutyrate mg/h of 1-aminocyclopropane-1-carboxylic
acid deaminase activity, respectively, which reduced levels of
stress hormone, ethylene in plants, and also produced indole-
3-acetic acid and salicyclic acid that can help plant growth
under abiotic stress. All these results indicated that these
copper-resistant rhizobacteria could confer copper resistance
and growth promotion to plants. |
