When growing in the field, plants are exposed to the effect of heavy metals as soon as the seed comes into contact with the soil solution. Therefore, we found important to study the effect of Cd and Ni on maize exposed to these heavy metals since sowing. The aim of this work was to examine which anatomical changes are induced by continuous intoxication of young maize root system with 0.1 mM Cd and Ni, thus modifying its growth and capacity for water and nutrient uptake. Concomitantly, the effect on concentration and distribution of Cd, Ni and some essential ions (Ca, Mg, Zn, Fe, Cu and Mn) was studied.

Increased nitrogen supply stimulates plant growth and photosynthesis. Since it was shown that heavy metals may cause deficiencies of essential nutri

The effect of different lead (Pb) concentrations in the nutrient solution on the growth, Pb and chlorophyll a+b content, chlorophyll fluorescence and quenching parameters in the leaves of young sunflower (Helianthus annuas L.) plants was studied. The content of Pb in the analyzed plant parts increased following the increase in Pb content in the nutrient medium. This increase was expressed to a higher extent in the roots than in the stems and leaves. In the presence of high concentration of Pb in the leaf area, the dry mass and the height of plants were reduced. Lead treatment of sunflower plants led to a pronounced reduction of chlorophyll (a+b) content, accompanied by much smaller decrease of photosynthetic O evaluation rate and PSll efficiency at low light intensity. Hence, Pb effect²did not result in the destruction of the photosynthetic apparatus, but in its reduction. The highest Pb concentration in the nutrient solution induced, however, at saturating photon flux density (PFD) a decrease in photochemical quenching and in the efficiency of PSll electron transport and significantly affected nonphotochemical fluorescence quenching, indicating an increase in proton gradient across the thylakoid membrane and a decrease of photophosphorylation.

This review highlights the importance of research for development of biofertilizer and biocontrol products based on the use of glycerol for further process scale-up to industrial microbiology. Glycerol can be used successfully in all stages of production of plant beneficial microorganisms. It serves as an excellent substrate in both submerged and solid-state fermentation processes with free and immobilized microbial cells. Glycerol is also one of the most attractive formulation agents that ensures high cell density and viability including in harsh environmental conditions. Future research is discussed to make this inexpensive material a base for industrial production of plant beneficial microorganisms.