BIOAVAILABILITY OF CADMIUM 
    Cation Exchange Capacity (CEC)
    pH
    Soil Amendments
    Competitive Cations
    Fertilizer
    Mycorrhizae
    Chelation
       Phytochelatins (PCs)
       Phytochelatin Effectiveness
       Role of Sulfur in PCs
       Oxidative Stress
       Translocation
       Metallothioneins
       Organic Acids
       EDTA / EGTA

CADMIUM TOLERANCE AND
ACCUMULATION IN PLANTS
    Cell Wall Binding
    Reduced Transport
    Compartmentalization
    Chelation
    Phytoextraction factors
       Table 1.  Plant Accumulation
       Hyperaccumulators

CONCLUSIONS

LINKS

BIBLIOGRAPHY

Organic Acids

     Citric and Malic acid are two compounds which have been shown to complex heavy metals in plant roots. After loss of one H+, each acid contains a COO- group  which binds to the cation positive charge. Plants secrete acids which aid in the uptake of non-bioavailable metals. These same acids protect cellular function when the acid-Cd complex is brought into the root. Citric acid metal complexes have been shown to translocate via the xylem (Senden, et al. 1990). If a plant could be genetically altered to produce higher levels of endogenous citric or malic acid, then perhaps phytoextraction could be enhanced.
 

Previous                    Next