DRY MATTER ACCUMULATION AND PHOTOSYNTHETIC PIGMENTS CONTENT IN RADISH (Raphanus sativus L.) AS INDICATORS OF COPPER AND LEAD TOXICITY

Uključivanje teških metala u metabolizam biljaka prouzročuje promjene specifičnih metaboličkih putova, poput procesa sinteze organske tvari. Biljke tri kultivara rotkvice izložene su tretmanu s 0,5 mM Cu, odnosno Pb u hranjivoj otopini tijekom 48 h. Sadržaj fotosintetskih pigmenata u listovima utvrđen je spektrofotometrijski i izražen na jedinicu mase suhe i svježe tvari lista. Manja akumulacija suhe tvari u listu i hipokotilu tretiranih biljaka rezultirala je relativnim povećanjem sadržaja pigmenata u suhoj tvari lista. Ovim je istraživanjem utvrđeno da je sadržaj fotosintetskih pigmenata, u uvjetima kratkog izlaganja navedenim teškim metalima, neprecizan pokazatelj njihove toksičnosti za rotkvicu.The involvement of heavy metals in plant metabolism leads to the alterations of specific metabolic pathways such as organic matter synthesis. The plantlets of three radish cultivars have been exposed to 0.5 mM Cu or Pb in nutrient solution for 48 h. The content of photosynthetic pigments was determined spectrophotometrically and expressed on leaf fresh and dry matter basis. The lower dry matter accumulation in leaves and hypocotylls of stressed plants was accompanied by the relative increment of pigments content in leaf dry matter. This research showed that the photosynthetic pigments content in short exposure conditions to mentioned heavy metals was inaccurate indicator of their toxicity in radish