Halophyte anti-oxidant feedback seasonality in two salt marshes with different degrees of metal contamination: search for an efficient biomarker

Salt marshes can be affected by metal contamination when near a polluted area, and this excessive concentration of metals is a source of stress in plants. Production of proteins, flavonoids, phenolic compounds and anti-oxidant feedback can be used as biomarkers, as well to assess the suitability of halophytes to function as a biomonitors. Through monitoring the anti-oxidative feedback in Halimione portulacoides (L.) Aellen, Sarcocornia fruticosa (L.) A.J.Scott and Spartina maritima (Curtis) Fernald in a contaminated and non-contaminated marsh, S. maritima seems to have potential as a bioindicator species, showing different biochemical characteristics according to the degree of contamination to which it is exposed. The evident biochemical separation between individuals from contaminated and non-contaminated salt marshes is mostly due to differences in the activity of SOD as well APx and GPx. Without neglecting the need for further works, the present study suggests that S. maritima enzymatic defences as good candidates for efficient biomarkers for estuarine sediment quality assessment studies.