Symbiotic efficiency of autochthonous arbuscular mycorrhizal fungus (G. mosseae) and Brevibacillus sp. isolated from cadmium polluted soil under increasing cadmium levels

• Published in: Environmental pollution (1987) 2003-11, Vol.126 (2), p.179-189
• Main Authors: Vivas, A, Vörös, I, Biró, B, Campos, E, Barea, J.M, Azcón, R
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; Arbuscular mycorrhizal fungus; Biological and medical sciences; Brevibacillus; Brevibacillus sp; Brevibacterium; Cadmium - toxicity; Cadmium levels; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; Fundamental and applied biological sciences. Psychology; Glomus mosseae; Mycorrhizae; Nickel - metabolism; Nitrogen - metabolism; Phosphorus - metabolism; Plant Leaves - growth & development; Plant Leaves - metabolism; Rhizobium sp; Soil Pollutants - toxicity; Symbiosis; Trifolium; Trifolium - drug effects; Trifolium - growth & development; Trifolium - metabolism; Trifolium repens; Zinc - metabolism
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/S0269-7491(03)00195-7

Selected ubiquitous microorganisms are important components of Cd tolerance in plants. The effect of inoculation with indigenous naturally occurring microorganisms [an arbuscular mycorrhizal (AM) fungus and rhizosphere bacteria] isolated from a Cd polluted soil was assayed on Trifolium repens growing in soil contaminated with a range of Cd. One of the bacterial isolate showed a marked PGPR effect and was identified as a Brevibacillus sp. Mycorrhizal colonization also enhanced Trifolium growth and N, P, Zn and Ni content and the dually inoculated (AM fungus plus Brevibacillus sp.) plants achieved further growth and nutrition and less Cd concentration, particularly at the highest Cd level. Increasing Cd level in the soil decreased Zn and Pb shoot accumulation. Coinoculation of Brevibacillus sp. and AM fungus increased shoot biomass over single mycorrhizal plants by 18% (at 13.6 mg Cd kg−1), 26% (at 33.0 mg Cd kg−1) and 35% (at 85.1 mg Cd kg−1). In contract, Cd transfer from soil to plants was substantially reduced and at the highest Cd level Brevibacillus sp. lowered this value by 37.5% in AM plants. Increasing Cd level highly reduced plant mycorrhization and nodulation. Strong positive effect of the bacterium on nodule formation was observed in all treatments. Results show that selected ubiquitous microorganisms, applied as enriched inocula, are important in plant Cd tolerance and development in Cd polluted soils.