Assessment of microbial activity and bacterial community composition in the rhizosphere of a copper accumulator and a non-accumulator

• Published in: Soil biology & biochemistry Vol. 40; no. 5; pp. 1167 - 1177
• Main Authors: Wang, YuanPeng, Li, QingBiao, Shi, JiYan, Lin, Qi, Chen, XinCai, Wu, Weixiang, Chen, YingXu
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-05-2008; New York, NY Elsevier Science
• Subjects: Agronomy. Soil science and plant productions; Biochemistry and biology; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; copper; Copper accumulator; Copper-contaminated soil; DNA fingerprinting; Elsholtzia; Elsholtzia splendens; Elzholtzia splendens; enzyme activity; forage crops; forage legumes; Fundamental and applied biological sciences. Psychology; gel electrophoresis; heavy metals; hyperaccumulators; microbial activity; microbial genetics; Microbiology; PCR-DGGE; phosphatase; phylogeny; Physics, chemistry, biochemistry and biology of agricultural and forest soils; polymerase chain reaction; Proteobacteria; Rhizosphere; shoots; Soil and water pollution; soil bacteria; soil enzymes; Soil science; species diversity; Trifolium repens; uptake mechanisms; Asia; China; PCR-DGGE; Rhizosphere; Elsholtzia splendens; Trifolium repens; Copper-contaminated soil; Copper accumulator; Community structure; Microbial activity; Copper-contaminated soil; PCR-DGGE; Elsholtzia splendens; Denaturing gradient gel electrophoresis; Annual plant; Soil pollution; Contamination; Polymerase chain reaction; Leguminosae; Labiatae; Trifolium repens; Rhizosphere; Copper accumulator; Dicotyledones; Angiospermae; Bacteria; Herbaceous plant; Spermatophyta; Soil science; Fodder crop; Bioremediation; Biological accumulation; Copper; Microbial community
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/j.soilbio.2007.12.010

Soil microorganisms may play an important role in the uptake of heavy metals from soils. However, assessments of bacterial activity and community composition in the rhizosphere of accumulators have been largely ignored. We studied potential effects of a copper (Cu)-accumulator,
Elsholtzia splendens, and a non-Cu-accumulator plant,
Trifolium repens, on soil microbial activity and community composition with increasing Cu addition. The results showed that concentrations of Cu in the shoots of
E. splendens were 2.1, 2.2 and 2.4 times those of
T. repens under the treatment of different Cu concentrations. Soil microbial biomass and phosphatase activity in the rhizosphere of
E. splendens were higher than those of
T.repens. PCR-denaturing gradient gel electrophoresis (PCR-DGGE) fingerprint analysis revealed that addition of Cu decreased the number of bands in bare soil and soil with
T. repens. However, there was a significant increase in the number of bands in soil with
E. splendens incorporated with either 200 or 500
mg
kg
−1 Cu. The abundances of five phylogenetic groups related most closely to
α-,
β-,
γ-
proteobacteria, Gram-positive bacteria and CFB group, respectively, were determined in the rhizosphere of plants. Some specific clone such as E13 (metal-contaminated soil clone K20-64) was found in the rhizosphere of
E. splendens. Results indicated that
E. splendens, as a Cu-accumulator, played an important role in governing soil microbial activity and bacterial community composition in the rhizosphere in response to Cu stress.