Mercury intracellular partitioning and chelation in a salt marsh plant, Halimione portulacoides (L.) Aellen: Strategies underlying tolerance in environmental exposure

Abstract

In the pres ence of metal stress, plants can resort to a series of tol er ance mech a nisms. There fore field studies should be under taken in order to eval u ate the real role of these mech a nisms in stress cop ing. The aim of this paper was to clar ify the bio chem i cal pro cesses behind mer cury tol er ance in Ha lim i one por tu la co ides (L.) Ael len (Caryo phyll ales: Cheno po di a ceae) col lected in a mer cury con tam i nated salt marsh. Dif fer ent frac tions of mer cury were sep a rated: buffer-sol u ble (mainly cyto solic) and insol u ble mer cury (mainly asso ci ated with mem branes and cell walls). The amounts in each frac tion of metal were com pared and related to metal dis tribu tion within plant organs. Pro tein-mer cury com plexes were iso lated and ana lysed for their thiol con tent in order to assess wether the tol er ance of this salt marsh plant was asso ci ated with the induc tion of metal che lation by phy to chel a tins. Over all, the mer cury tol er ance strat e gies of the plant are likely to involve root cell wall immo bi li za tion as a major mech a nism of metal resis tance, rather than metal che la tion in the cyto solic fraction. Nev er the less, phy to chel a tins were dem on strated to che late mer cury under envi ron men tal expo sure.

Antioxidant system breakdown in brain of feral golden grey mullet (Liza aurata) as an effect of mercury exposure

“…Moreover, Pacheco et al (2005) assessed the levels of priority polycyclic aromatic hydrocarbons (PAHs) also reporting low levels. Accordingly, Laranjo Basin has been recurrently adopted as a ''field laboratory'', offering a unique opportunity to assess mercury toxicity (Guilherme et al 2008;Válega et al 2009). Three locations (R, L1 and L2) were chosen according to the existing contamination gradient (Fig.…”

Antioxidant response of Phragmites australis to Cu and Cd contamination

“…Information on this matter regarding salt marsh plants is still scarce. In fact, till now, only two studies using specimens adapted to salty environments were published: one regarding the presence of thiolic proteins in Halimione portucaloides tissues (Válega et al, 2009) and other regarding PC in Spartina maritima tissues (Padinha et al, 2000). Present experiments were carried out in vitro, rhizosediment soaked with the respective elutriate solution (prepared with estuarine water) being used as contaminated medium (after being spiked with Cu or Cd).…”

The influence of compost and nitrilotriacetic acid on mercury phytoextraction by Lepidium sativum L.

“…This tendency of higher Hg accumulation in plant roots than shoots can be seen as a strategy for protecting the more sensitive parts from the deleterious effects induced by metal stress . Mercury ions are preferably retained in roots and only small concentrations are transferred to leaves . Mercury accumulation by L. sativum L. was correlated with GSH synthesis.…”