YTTRIUM - ACCUMULATION, TRANSLOCATION AND DISTRIBUTION IN YOUNG SUNFLOWER PLANTS (Helianthus annuus L.)

Even though yttrium (Y), similarly to the other rare earth elements, is widely present in the soils and plants, there is little experimental data describing its effects on plant growth and metabolism. Therefore, the aim of this work was to examine the effect of 10(-5), 10(-4) and 10(-3) M Y on growth, photosynthetic pigments, Y accumulation and transfer factors in young sunflower plants grown in semi-controlled conditions, in water cultures. In the presence of Y, growth of young sunflower was reduced. Plant dry weight, water content, height, leaf area, concentration of chlorophylls a, b and carotenoids declined significantly at 10(-4) M Y. Concentration of Y and transfer factor were the highest in roots at 10(-3) and le M Y respectively, and the lowest in leaves. At 10(-3) M Y plant growth and development practically stopped. Mechanisms by which omnipresent Y affects plant metabolism remain to be studied profoundly in the future.