| Abstract | Kadmij je široko rasprostranjen, neesencijalan teški metal, koji je toksičan za biljne organizme. Cink je važan esencijalni element, uključen u važne metaboličke procese, primjerice aktivnost i sintezu proteina i nukleinskih kiselina, fotosintezu, a potreban je za normalan rast biljaka. Cilj istraživanja bio je utvrditi utjecaj kadmija (10 μM) i cinka (50 i 100 μM), te njihove kombinacije, na vodenu leću (Lemna minor L.). Kao pokazatelji oksidacijskog stresa praćeni su rast, sadržaj vodikovog peroksida, malondialdehida i karbonila, aktivnost lipoksigenaze te prisutnost proteina toplotnog stresa. Utvrđeno je da kadmij (10 μM) inhibira rast i uzrokuje oksidacijski stres što je vidljivo po porastu sadržaja vodikovog peroksida, malondialdehida i karbonila, te povećanoj aktivnosti enzima lipoksigenaze. Više koncentracije cinka (100 μM) uzrokuju umjereni oksidacijski stres, prilikom čega je primijećen smanjen prirast biljaka i povećan sadržaj vodikovog peroksida i karbonila. Cink u koncentraciji od 50 μM nije uzrokovao oksidacijski stres. Pri istovremenom tretmanu kadmijem (10 μM) i višom koncentracijom cinka (100 μM) uočeno je da je cink ublažio djelovanje kadmija. Prirast biljaka je bio viši, uz istovremeno smanjenje lipidne peroksidacije i aktivnosti lipoksigenaze, a prisutna je bila i dodatna izoforma proteina toplotnog stresa molekularne mase ~ 69 kDa. Istovremeni tretman kadmijem i nižom koncentracijom cinka (50 μM) nije doveo do smanjenja oksidacijskog stresa. |
| Abstract (english) | Cadmium is a widespread, non-essential heavy metal, which is toxic to plant organisms. Zinc is an essential element, involved in important metabolic processes, such as activity and synthesis of proteins and nucleic acids, photosynthesis, and is required for normal plant growth. The aim of this study was to determine the effect of cadmium (10 μM) and zinc (50 and 100 μM), and their combinations, on duckweed (Lemna minor L.). Growth, content of hydrogen peroxide, malondialdehyde, carbonyls, activity of lipoxygenase and presence of heat shock proteins were observed as indicators of oxidative stress. It was found that cadmium (10 μM) inhibited growth and caused oxidative stress, which was evident by the increased contents of hydrogen peroxide, malondialdehyde and carbonyls, and increased activity of the lipoxygenase. Higher concentration of zinc (100 μM) caused a moderate oxidative stress, during which the reduced growth and increased content of hydrogen peroxide and carbonyls were present. Zinc at a concentration of 50 μM did’t cause oxidative stress. In combined action of cadmium (10 μM) and higher concentration of zinc (100 μM) it was observed that zinc alleviated effects of cadmium. The growth rate was higher, lipid peroxidation and activity of lipoxygenase were reduced, and an additional isoform of heat shock protein, molecular weight ~69 kDa, was present. In combination of cadmium and zinc, when zinc was present in lower concentration (50 μM), the results did’t show reduction in oxidative stress. |
