Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Hangzhou 310058, China.
Department of Animal, Plant and Soil Sciences, Centre for AgriBioscience, La Trobe University, Melbourne Campus, Bundoora, VIC 3086, Australia.
Environ Pollut. 2020 Feb;257:113580. doi: 10.1016/j.envpol.2019.113580. Epub 2019 Nov 8.
Plant-specific root-microbe-soil interactions play an indisputable role in microbial adaptation to environmental stresses. However, the assembly of plant rhizosphere microbiomes and their feedbacks in modification of pollution alleviation under organochlorine stress condition is far less clear. This study examined the response of root-associated bacterial microbiomes to lindane pollution and compared the dissipation of lindane in maize-cultivated dry soils and rice-cultivated flooded soils. Results showed that lindane pollution dramatically altered the microbial structure in the rhizosphere soil of maize but had less influence on the microbial composition in flooded treatments regardless of rice growth, when the reductive dechlorination of lindane was actively coupled with natural redox processes under anaerobic conditions. After 30 days of plant growth, lindane residues dissipated much faster in anaerobic than in aerobic environments, with only 1.08 mg kg lindane remaining in flooded control compared to 12.79 mg kg in dry control soils. Compared to the corresponding unplanted control, maize growth significantly increased, but rice growth slightly decreased the dissipation of lindane. Our study suggests that opposite impacts would lead to the self-purification of polluted soils during the growth of xerophytic maize and hygrocolous rice. This was attributed to the contrasting belowground micro-ecological processes regarding protection of root tissues and thereby assembly of rhizosphere microbiomes shaped by the xerophytic and hygrocolous crops under different water managements, in response to lindane pollution.
植物-根际微生物-土壤相互作用在微生物适应环境胁迫方面起着不可忽视的作用。然而，在有机氯污染胁迫条件下，植物根际微生物组的组装及其对污染缓解的反馈作用还远不清楚。本研究考察了根相关细菌微生物组对林丹污染的响应，并比较了林丹在玉米种植的旱地和水稻种植的水田中污染缓解的情况。结果表明，林丹污染显著改变了玉米根际土壤中的微生物结构，但对淹水处理中的微生物组成影响较小，而不管水稻的生长情况如何，因为在厌氧条件下，林丹的还原脱氯与自然氧化还原过程紧密耦合。在植物生长 30 天后，林丹残留物在厌氧环境中比在好氧环境中消散得更快，与旱地对照相比，淹水对照中仅残留 1.08 mg/kg 的林丹，而旱地对照中残留 12.79 mg/kg 的林丹。与相应的无植物对照相比，玉米生长显著增加，但水稻生长略微降低了林丹的消解。本研究表明，在耐旱玉米和喜湿水稻生长期间，相反的影响会导致污染土壤的自净。这归因于在不同水分管理下，耐旱和喜湿作物对根组织的保护以及由此形成的根际微生物组组装的地下微生态过程的差异，从而对林丹污染做出响应。
