The duality of sulfate-reducing bacteria: Reducing methylmercury production in rhizosphere but enhancing accumulation in rice plants.
J Hazard Mater
; 476: 135049, 2024 Sep 05.
Article
em En
| MEDLINE
| ID: mdl-38970973
ABSTRACT
Sulfate-reducing bacteria (SRB) are known to alter methylmercury (MeHg) production in paddy soil, but the effect of SRB on MeHg dynamics in rhizosphere and rice plants remains to be fully elucidated. The present study investigated the impact of SRB on MeHg levels in unsterilized and γ-sterilized mercury-polluted paddy soils, with the aim to close this knowledge gap. Results showed that the presence of SRB reduced MeHg production by â¼22 % and â¼17 % in the two soils, but elevated MeHg contents by approximately 55 % and 99 % in rice grains, respectively. Similar trend at smaller scales were seen in roots and shoots. SRB inoculation exerted the most profound impact on amino acid metabolism in roots, with the relative response of L-arginine positively linking to MeHg concentrations in rhizosphere. The SRB-induced enrichment of MeHg in rice plants may be interpreted by the stronger presence of endophytic nitrogen-related microbes (e.g. Methylocaldum, Hyphomicrobium and Methylocystis) and TGA transcription factors interacting with glutathione metabolism and calmodulin. Our study provides valuable insights into the complex effects of SRB inoculation on MeHg dynamics in rice ecosystems, and may help to develop strategies to effectively control MeHg accumulation in rice grains.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oryza
/
Poluentes do Solo
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Rizosfera
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Compostos de Metilmercúrio
Idioma:
En
Revista:
J Hazard Mater
/
J. hazard. mater
/
Journal of hazardous materials
Assunto da revista:
SAUDE AMBIENTAL
Ano de publicação:
2024
Tipo de documento:
Article