title: Allelopathic effects of volatile organic compounds from Eucalyptus grandis rhizosphere soil on Eisenia fetida assessed using avoidance bioassays, enzyme activity, and comet assays.
abstract: Allelopathy has been identified as an underlying mechanism of detrimental environmental impacts within commercial plantations. Eucalyptus spp. are known to generate huge amounts of volatile organic compounds (VOCs) that can function as phytotoxins and thus inhibit other plants. In the present study, biochemical markers, including activities of acetylcholinesterase (AChE) and oxidative stress enzymes, such as superoxide dismutase (SOD) and glutathione S-transferase (GST), were assayed to assess changes in Eisenia fetida at the physiological level induced by different doses of VOCs as part of an acute toxicity test over 7 and 14-day exposures. In addition, the toxicities of VOCs were investigated using a soil avoidance test and comet assay. The results revealed that E. fetida exhibited significant avoidance behavior towards the highest concentrations of undecane, decane, 2,4-dimethyl heptane, and 2,2,4,6,6-pentametyl heptane. The tail DNA percentages were significantly increased for all experimental treatments relative to control. However, under the treatments of VOCs, Olive tail moment content and comet tail length also display an obvious increase compared to control, except for that of octane, undecane and decane treatments. As VOC concentrations and durations increased in the soil, activities of AChE, SOD, and GST were either stimulated or inhibited. Among the VOCs, decane, 2,4-dimethyl heptane, 2,2,4,6,6-pentamethyl heptane, and 2,4-di tert buyl phenol exerted stronger effects on enzymatic activities. In summary, VOCs in rhizosphere soils of E. grandis might exert a toxic impact on E. fetida, among which 2,4-dimethyl heptane, 2,2,4,6,6-pentamethyl heptane, and 2,4-di tert buyl phenol have the strongest effects.
authors.affiliation: Institute of Ecological Forestry, Sichuan Provincial Key Laboratory of Ecological Forestry Engineering, College of Forestry, Sichuan Agricultural University, Wenjiang 611130, China.
authors.forename: Tang
authors.initials: T
authors.lastname: Zhiqun
authors.affiliation: Institute of Ecological Forestry, Sichuan Provincial Key Laboratory of Ecological Forestry Engineering, College of Forestry, Sichuan Agricultural University, Wenjiang 611130, China.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Jian
authors.affiliation: Institute of Ecological Forestry, Sichuan Provincial Key Laboratory of Ecological Forestry Engineering, College of Forestry, Sichuan Agricultural University, Wenjiang 611130, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Junli
authors.affiliation: Institute of Ecological Forestry, Sichuan Provincial Key Laboratory of Ecological Forestry Engineering, College of Forestry, Sichuan Agricultural University, Wenjiang 611130, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Chunzi
authors.affiliation: Institute of Ecological Forestry, Sichuan Provincial Key Laboratory of Ecological Forestry Engineering, College of Forestry, Sichuan Agricultural University, Wenjiang 611130, China. Electronic address: zdj_8080573@sohu.com.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Danju
mesh_terms: D064089:Allelopathy; D000818:Animals; D001681:Biological Assay; D015415:Biomarkers / Q000378:metabolism; D020552:Comet Assay; D004249:DNA Damage / Q000187:drug effects*; D005052:Eucalyptus / Q000737:chemistry / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D009835:Oligochaeta / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D058441:Rhizosphere; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000633:toxicity*; D013482:Superoxide Dismutase / Q000378:metabolism; D055549:Volatile Organic Compounds / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D012987:Soil; D012989:Soil Pollutants; D055549:Volatile Organic Compounds; D008315:Malondialdehyde; D013482:Superoxide Dismutase; D005982:Glutathione Transferase
keywords: AChE; Antioxidant enzyme; DNA damage; Ecotoxicology; Eisenia fetida; Volatile organic compounds