Global patterns of accumulation and partitioning of metals in halophytic saltmarsh taxa: A phylogenetic comparative approach

• Published in: Journal of hazardous materials 2021-07, Vol.414, p.125515-125515, Article 125515
• Main Authors: Alam, Md Rushna, Islam, Rafiquel, Anh Tran, Thi Kim, Van, Diep Le, Rahman, Mohammad Mahmudur, Griffin, Andrea S., Yu, Richard Man Kit, MacFarlane, Geoff R.
• Format: Article
• Language: English
• Subjects: Bioconcentration factor; Halophyte; Salinity tolerance; Trace metals; Translocation factor
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.125515

The current study represents the first attempt to analyse quantitatively, within a phylogenetic framework, uptake and partitioning patterns of copper (Cu), zinc (Zn), cadmium (Cd) and lead (Pb) in extant saltmarsh taxa globally, and to assess associations of these patterns with various plant traits indicative of their halophytic adaptations. Despite saltmarsh being diverse taxonomically, most saltmarsh taxa accumulate metals to roots at, or above, unity (> 1). Further, there is significant translocation from roots to shoot for Cu, Zn and Cd (≤ 1), however, Pb is less mobile (TF = 0.65). Patterns of accumulation were similar among families, except greater Cd accumulation to roots in members of Juncaceae. Patterns of uptake to roots and translocation to leaves were broadly similar among plant type, plant form, habitat and photosynthetic mode. Zinc is lower in the leaves of salt-secreting species for some closely related taxa, suggesting some species co-excrete sodium (Na+) and Zn2+ through glands in leaf tissue. Salinity tolerance has no relationship to metal uptake and translocation. Translocation of Zn is greater at lower Zn sediment exposures, reflecting its active uptake and essentiality, but such bias does not affect outcomes of analyses when included as a covariate. [Display omitted] •Patterns of metal distribution explored in halophytes via comparative analysis.•Metal BCFs and TFs did not vary among families or plant attribute groups.•Translocation of Cu, Zn and Cd was higher than Pb in halophytes.•Zn loading in leaves was greater at lower metal exposures.•No relationship between metal BCF/TFs and species salinity tolerance.