Vpliv različnih oblik selena in živega srebra na fiziološke in biokemijske lastnosti male vodne leče

Čibej, Cene (author), Germ, Mateja (mentor), Golob, Aleksandra (co-mentor)

Živo srebro je kovina, ki v različnih oblikah globalno kroži v atmosferi, vodi in prsti. Akumulira se vzdolž prehranjevalne verige, kjer rastline predstavljajo primarni vir hrane. Na bioakumulacijo živega srebra v rastlini vplivajo drugi elementi, med njimi selen. Selen lahko pripomore k zaščiti živali pred toksičnimi učinki živega srebra. Vpliv selena na negativne učinke živega srebra pri rastlinah še ni dobro raziskan. Selen je element v sledovih, ki je za ljudi in živali esencialen. Esencialnost selena za rastline ni dokazana, vendar pri rastlinah v nizkih koncentracijah spodbuja rast ter povečuje antioksidativno sposobnost. Namen magistrske naloge je bil raziskati vpliv različnih oblik selena in živega srebra ter njunih kombinacij na fiziološke in biokemijske lastnosti male vodne leče (Lemna minor). Rastline smo v rastni komori izpostavili natrijevemu selenatu (Na2SeO4), natrijevemu selenitu (Na2SeO3) in živo srebrovemu (II) kloridu (HgCl2). Koncentracija obeh oblik selena (Se(IV), Se(VI)) in Hg je bila v končni raztopini 250 mL Steinberovega gojišča 0,5 µM. Pripravili smo vzorce male vodne leče za merjenje izbranih biokemijskih lastnosti (vsebnost fotosinteznih barvil (klorofil a in b, karotenoidi)), vsebnost antocianov in UV absorbirajočih snovi, malondialdehida (MDA) in vsebnost selena in živega srebra v vzorcih male vodne leče. Dodatek natrijevega selenita (Na2SeO3), natrijevega selenata (Na2SeO4) in kombinacija natrijevega selenita (Na2SeO3) in živosrebrovega (II) klorida (HgCl2) ter natrijevega selenita (Na2SeO3) in živosrebrovega (II) klorida (HgCl2), je imel negativen vpliv na vsebnost fotosinteznih barvil in antocianov. Dodatek živosrebrovega (II) klorida (HgCl2) ni vplival na vsebnost fotosinteznih barvil, fotokemično učinkovitost fotosistema FS II, različne oblike selena pa niso bistveno vplivale na koncentracije Hg v mali vodni leči.

• Language: Slovenian
• Keywords: selen, živo srebro, fiziološke, biokemijske lastnosti, mala vodna leča
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: [C. Čibej]
• Year: 2022
• PID: 20.500.12556/RUL-137630
• UDC: 581
• COBISS.SI-ID: 112790787
• Publication date in RUL: 24.06.2022

Secondary language

• Language: English
• Title: Effect of different forms of selenium and mercury on physiological and biochemical properties of common duckweed

Abstract

Mercury is a heavy metal that circulates globally in various forms in the atmosphere, water and soil. Mercury accumulates along the food chain, where plants are the primary food source. The bioaccumulation of mercury in the plant is influenced by other elements, including selenium. Selenium can help protect animals from the toxic effects of mercury. The effect of selenium on the negative effects of mercury in plants has not yet been well studied. Selenium is a trace element that is essential for humans and animals. The essentiality of selenium for plants has not been proven, but in plants in low concentrations it stimulates growth and increases antioxidant capacity. The purpose of the research was to investigate the influence of different forms of selenium and mercury and their combinations on the physiological and biochemical properties of common duckweed. Plants were exposed to sodium selenate (Na2SeO4), sodium selenite (Na2SeO3) and mercury (II) chloride (HgCl2) in the growth chamber. The concentration of both forms of selenium (Se (IV), Se (VI)) and Hg in the final 250 mL solution of Steinber medium was 0.5 µM. The photochemical efficiency of photosystem (PS) II plants was measured with a modulation fluorometer (PAM 2500). Common duckweed samples were prepared to measure selected biochemical properties (content of photosynthetic pigments (chlorophyll a and b, carotenoids)), anthocyanin and UV absorbing content, MDA and content selenium and mercury in common duckweed. The addition of sodium selenite (Na2SeO3), sodium selenate (Na2SeO4), and the combination of sodium selenite (Na2SeO3) and mercury (II) chlorde (HgCl2), sodium selenate (Na2SeO4) and mercury (II) chloride (HgCl2) all negatively affected the content of photosynthetic pigments and anthocyanins. The addition of mercury (II) chloride did not affect the content of photosynthetic pigments, the photochemical efficiency of PS II, and the different forms of selenium did not significantly affect the Hg concentrations in the common duckweed.

• Keywords: selenium, mercury, physiological, biochemical properties, common duckweed