Influence of plant growth promoting bacteria and Cr6+ on the growth of Indian mustard

• Published in: Chemosphere (Oxford) 2006-02, Vol.62 (5), p.741-748
• Main Authors: Rajkumar, M, Nagendran, R, Lee, K.J, Lee, W.H, Kim, S.Z
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; Bacillus (bacteria); Bacillus - drug effects; Bacillus - isolation & purification; Bacillus - metabolism; Biological and medical sciences; biosynthesis; Brassica juncea; chromium; Chromium - pharmacokinetics; Chromium - pharmacology; Conservation, protection and management of environment and wildlife; Dose-Response Relationship, Drug; Drug Resistance, Bacterial; Environmental degradation: ecosystems survey and restoration; Fundamental and applied biological sciences. Psychology; indole acetic acid; Indoleacetic Acids - metabolism; metal tolerance; Mustard Plant - drug effects; Mustard Plant - growth & development; Mustard Plant - microbiology; phosphates; Phosphates - metabolism; plant growth; plant growth-promoting rhizobacteria; Pseudomonas; Pseudomonas - drug effects; Pseudomonas - isolation & purification; Pseudomonas - metabolism; siderophores; soil pollution; Solubility; water solubility
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2005.04.117

The Cr(6+) resistant plant growth promoting bacteria (PGPB), Pseudomonas sp. PsA4 and Bacillus sp. Ba32 were isolated from heavy metal contaminated soils and their plant growth promoting activity on the Indian mustard (Brassica juncea) were assessed with different concentrations of Cr(6+) in soil. Production of siderophores and the solubilization of phosphate were observed in both strains, PsA4 and Ba32. Production of IAA was only observed in strain PsA4. Inoculation of PsA4 or Ba32 promoted the growth of plants at 95.3 and 198.3 microg of Cr(6+)g(-1) soil. The maximum growth was observed in the plants inoculated with strain PsA4. Both strains, PsA4 and Ba32 did not influence the quantity of accumulation of chromium in root and shoot system. The present observations showed that the strains PsA4 and Ba32 protect the plants against the inhibitory effects of chromium, probably due to the production of IAA, siderophores and solubilization of phosphate.