Details

Autor(en) / Beteiligte

• Wang, Meng
• Wang, Lifu
• Zhao, Shuwen
• Li, Shanshan
• Lei, Xiaoqin
• Qin, Luyao
• Sun, Xiaoyi
• Chen, Shibao

Titel

Manganese facilitates cadmium stabilization through physicochemical dynamics and amino acid accumulation in rice rhizosphere under flood-associated low pe+pH

Ist Teil von

• Journal of hazardous materials, 2021-08, Vol.416, p.126079-126079, Article 126079

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2021

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• Periodic flooding in paddy soils impacts redox behavior and induces variations in pe+pH levels. Manganese (Mn) is capable of reducing cadmium (Cd) uptake by rice. However, the processes involved in how Mn alters Cd mobilization under different pe+pH environments remain poorly understood. To investigate the mechanisms of Mn-mediated soil Cd-stabilization and subsequent inhibition of Cd uptake from flooded soils, we examined Cd immobilization in soil pot incubations, transcriptional changes in Cd-transport genes, and metabolomic analyses of roots and rhizosphere soils with or without Mn application. We found a decrease in extractable Cd concentration largely depended on irrigation-associated low pe+pH, exogenous Mn enhancement of Fe−Mn (oxyhydro)oxide-mediated Cd transformation, and Cd deposition in rice Fe/Mn plaques. Mn application led to striking effects on the expression of Cd-related genes eg. IRT, HMA, and NRAMP in rice root tissue. Exposure to Mn under variable pe+pH levels resulted in metabolic reprogramming of soil and rice roots. Mn induced amino acid synthesis in rice roots, leading to rhizosphere accumulation of free L-lysine, glycine, and glutamine, which can reportedly bind metal ions, forming complexes with Cd. Thus, secreted amino acids, low pe+pH, and free Mn can together comprise a multi-faceted approach to managing Cd toxicity in rice. [Display omitted] ●Mn facilitated soil Cd stabilization and inhibited rice Cd uptake under low pe+pH.●Fe−Mn (oxyhydro)oxides mediated soil Cd deposition in Fe/Mn plaques.●The application of Mn triggered the synthesis and secretion of amino acids in rice.●Amino acids in rhizosphere displayed negative correlations with Cd availability.