magistrsko delo
Kaja Katona (Author), Katarina Vogel-Mikuš (Mentor), Katarina Vogel-Mikuš (Thesis defence commission member), Mojca Narat (Thesis defence commission member), Iztok Prislan (Thesis defence commission member)

Abstract

Onesnaženost okolja s kovinami predstavlja velik ekološki in gospodarski problem. V prisotnosti velikih koncentracij kovin, lahko kopenske rastline razvijejo dve strategiji, da se zaščitijo: izključevanje ali akumulacijo in skladiščenje kovin. Nikelj je kovina in v rastlini lahko doseže velike koncentracije. V normalnih tleh se Ni nahaja v koncentracijah od 1 – 450 mg/ kg. V tleh bogatih z Ni pa lahko koncentracija Ni doseže 450 – 26 000 mg/ kg. Hiperakumulatorji lahko vsebujejo več kot 1000 mg Ni na kg suhe mase. Namen naloge je torej raziskati porazdeljevanje in vezavne oblike Ni pri dveh podvrstah rastlinske vrste Berkheya zeyheri, ki je endemična za serpentinska tla v Južni Afriki. Razporeditev Ni na organskem in tkivnem nivoju smo določili z metodami XRF, mikro-PIXE, na celičnem nivoju (topni in netopni del) pa z ekstrakcijo, ICP-MS in XRF. Vezavne oblike Ni v tkivih smo določili z metodo ekstrakcije in tekočinske kromatografije (LC). Rezultati so pokazali, da so pri hiperakumulacijski podvrsti B. zeyheri koncentracije Ni v rastlini večje, kot v tleh. Največja koncentracija Ni pa je bila v listih. Nikelj se pri hiperakumulacijski populaciji kopiči v listih, pri neakumulacijski pa v koreninah. V listih se Ni nahaja v fotosintezno neaktivnih (povrhnjica) in aktivnih (mezofil) tkivih. Na celičnem nivoju pa se Ni nahaja v vakuolah in celični steni. Rezultato LC kažejo, da je večina Ni v ionski obliki oz. kot Ni-citrat.

Keywords

nikelj;hiperakumulacijske rastline;Berkheya;organske kisline;Južna Afrika;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [K. Katona]
UDC: 581.5:582.991:669.24:502.174(043.2)
COBISS: 8817273 Link will open in a new window
Views: 956
Downloads: 278
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Other data

Secondary language: English
Secondary title: Localization and ligand environment of nickel in hyperaccumulating plants from the genus Berkheya from South Africa
Secondary abstract: Environmental contamination by metals represents a major environmental and economic problem. In the presence of high concentrations of metals, the terrestrial plants may develop two strategies in order to protect themselves. Those strategies are: exclusion or accumulation; and sequestration of metals. Nickel is a metal and can reach a high concentration in the plant. In normal soil Ni is present at concentrations in the range from 1 to 450 mg/ kg. In the Ni-rich soil, the concentration can reach 450 - 26 000 mg/ kg. Hyperaccumulators can contain more than 1 000 mg per kg of dry mass. The purpose of this thesis is, therefore, to explore the distribution and binding forms of Ni in two different subspecies of the plant species Berkheya zeyheri, which is endemic to the serpentine soil in South Africa. The distribution of Ni on organic and tissue level was determined by the following methods: XRF and micro-PIXE, whereas on at the cell level (soluble and insoluble part), this was done by extraction, ICP-MS and XRF. The binding forms of Ni in tissues were determined with the method of extraction and liquid chromatography (LC). The results have shown that in the case of the hyperaccumulating subspecies of B. zeyheri, the Ni concentration is higher than in soil. The highest concentration of Ni was in the leaves. In case of the hyperaccumulating population, Ni is concentrated in the leaves, whereas with the non-accumulation population, it is concentrated in the roots. In the leaves, Ni is located in photosynthetic inactive (epidermis) and as well as active (mesophyll) tissues. On the cellular level, Ni is located in vacuoles and cell wall. LC-MS show that the majority of Ni is present in plant tissues in ionic form or as Ni-citrate.
Secondary keywords: nickel;hyperaccumulating plants;Berkheya;organic acids;South Africa;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Študij biotehnologije
Pages: XI, 77 f., [10] f. pril.
ID: 10910410