Effects of Fe plaque and organic acids on metal uptake by wetland plants under drained and waterlogged conditions. (December 2017)

• Record Type: Journal Article
• Authors: Li, W.C.; Deng, H.; Wong, M.H.
• Is Part Of: Environmental pollution. Volume 231:Part 1(2017)
• Page Start: 732
• Page End: 741
• Publication Date: 2017-12
• Subjects: Metal tolerance -- Metal accumulation -- Rhizosphere -- Fe plaque -- Organic acids; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2017.08.012
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: This study aims to assess the role of Fe plaque in metal uptake and translocation by different wetland plants and examine the effects of organic acids on metal detoxification in wetland plants. It was found that although exposed to a similar level of metals in rhizosphere soil solution, metal uptake by shoots of Cypercus flabelliformis and Panicum paludosum was greatly reduced, consequently leading to a better growth under flooded than under drained conditions. This may be related to the enhanced Fe plaque in the former, but due to the decreased root permeability in the latter under anoxic conditions. The Fe plaque on root surface has potential to sequester metals and then reduce metal concentrations and translocation in shoot tissues. However, whether the Fe plaque acts as a barrier to metal uptake and translocation may also be dependent on the root anatomy. Although metal tolerance in wetland plants mainly depends upon their metal exclusion ability, the higher-than-toxic-level of metal concentrations in some species indicates that internal metal detoxification might also exist. It was suggested that malic or citric acid in shoots of P. paludosum and C. flabelliformis may account for their internal detoxification for Zn. Highlights: The role of Fe plaque in metal uptake and translocation by wetland plants. Reduction of metal uptake by shoots of P. paludosum and C. flabelliformis . Effects of organic acids on metal detoxification in wetland plants. Fe plaque can sequester and reduce metal concentrations and shoot translocation. Malic or citric acid in shoots may account for internal detoxification for Zn.