Essential metals

Copper

(Cu)

? Constituent of enzymes;

? Role in photosynthesis and several physiological processes;

? Involved in reproductive and in determining yield and quality in crops (disease resistance)

? Disruption of photosynthesis, plant growth and reproductive processes;

? Decreases thylakoid surface area

Nickel

(Ni)

? Constituent of enzymes

? Activation of urease

? Reduction of:

? seed germination;

? protein production;

? chlorophyll and enzyme production;

? accumulation of dry mass

Zinc

(Zn)

? Constituent of cell membranes;

? Component of a variety of enzymes;

? DNA transcription;

? Involved in reproductive phase and in determining yield and quality of crops;

? Resistance against biotic and abiotic stress;

? Legume nodulation and nitrogen fixation

? Reduces nickel toxicity and seed germination

Non- essential metals

Cadmium

(Cd)

?

? Decreases seed germination, lipid content and plant growth

? Disturb enzyme activities,

? Inhibit the DNA-mediated transformation in microorganisms,

? Interfere in the symbiosis between microbes and plants,

? Increase plant predisposition to fungal invasion

Chromium

(Cr)

?

? Causes decrease in enzyme activity and plant growth;

? Produces membrane damage, chlorosis and root damage.

Lead

(Pb)

?

? Reduces chlorophyll, chlorosis, necrosis;

? Inhibit root and shoot growth

? Less biomass production

? affecting seed germination