title: Dissipation of phenanthrene and pyrene at the aerobic-anaerobic soil interface: differentiation induced by the rhizosphere of PAH-tolerant and PAH-sensitive rice (Oryza sativa L.) cultivars.
abstract: A pot experiment was conducted to reveal the removal of two polycyclic aromatic hydrocarbons (PAHs) (phenanthrene, PHE, and pyrene, PYR) during rice cultivation in a paddy field. The rhizosphere effect on facilitating dissipation of PAHs varied simultaneously as a function of soil properties, PAH types, cultivation time, and genotypes within rice cultivars, with differences performed for PYR but not PHE. Changes in soil PLFA profiles evidenced that the growth of rice roots modified the dominant species within rhizosphere microbial communities and induced a selective enrichment of Gram-negative aerobic bacteria capable of degrading, thereby resulting in the differentiated dissipation of PYR. While the insignificant differences in PHE dissipation might be attributed to its higher solubility and availability under flooded condition that concealed the differences in improvement of bioavailability for microorganisms between rhizosphere and non-rhizosphere, and between both soils and both rice cultivars. Our findings illustrate that the removal of PAHs in paddy soils was more complex relative to those in dryland soils. This was possibly due to the specialty of rice roots for oxygen secretion that provides development of redox heterogeneous microbial habitats at root-soil interface under flooded condition.
authors.affiliation: College of Environmental and Natural Resource Sciences, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: He
authors.forename: Wen
authors.initials: W
authors.lastname: Xia
authors.forename: Xinfeng
authors.initials: X
authors.lastname: Li
authors.forename: Jiajiang
authors.initials: J
authors.lastname: Lin
authors.forename: Jianjun
authors.initials: J
authors.lastname: Wu
authors.forename: Jianming
authors.initials: J
authors.lastname: Xu
mesh_terms: D001673:Biodegradation, Environmental; D018533:Biomass; D005227:Fatty Acids / Q000032:analysis; D059013:Microbial Consortia; D012275:Oryza / Q000737:chemistry*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism; D010616:Phenanthrenes / Q000378:metabolism*; D018517:Plant Roots / Q000737:chemistry* / Q000201:enzymology; D018520:Plant Shoots / Q000254:growth & development; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism; D011721:Pyrenes / Q000378:metabolism*; D058441:Rhizosphere; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D010616:Phenanthrenes; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; D012987:Soil; D012989:Soil Pollutants; C031181:phenanthrene; C030984:pyrene; D010088:Oxidoreductases