magistrsko delo
Metka Krajnc (Avtor), Jana Ambrožič-Dolinšek (Mentor), Špela Mechora (Komentor)

Povzetek

V magistrskem delu smo raziskovali vpliv različnih koncentracij selenita (0,01, 0,1, 1, 10 in 50 mg/l) in arzenata (20, 40, 60 in 80 mg/l) v kombinaciji z 1 mg Se(IV)/L na rastne parametre, fotokemično učinkovitost, fotosintezna barvila, antoccianine, vsebnost glutationa in cisteina pri ozkolistnem košcu (Berula erecta) v in vitro pogojih. Rastline smo gojili na preprostem MS gojišču Murashige in Skoog (1962), brez rastnih regulatorijev. Posamezni poskus je trajal tri tedne. Nizke koncentracije selenita (0,01, 0,1 in 1 mg/l) so pospešile rast poganjkov in korenin, ter stimulirale tvorbo stolonov in brstov, medtem ko so višje koncentracije (10 in 50 mg Se(IV)/l) zavrle rast rastlin. Najbolj stimulativen vpliv na preučevane rastne parametre je imela koncentracija 1 mg Se(IV)/l, zato smo jo tudi izbrali za preučavenje interakcije z arzenatom. Koncentracija 50 mg Se(IV)/l je imela intenzivno negativen vpliv na potencialno fotokemično učinokvitost fotosistema II. Vsebnost barvil se je znižala pri vseh obravnavah selenita, privzem celokupnega selena pa se je z naraščajočo koncentracijo selenita višal. Mejna koncentracija, do katere je naraščala vsebnost skupnega glutationa in cisteina v koreninah in poganjkih, je bila 1 mg Se(IV)/l, pri višjih koncentracijah pa je selen spremenil svojo naravo delovanja in začel delovati kot prooksidant ter posledično znižal koncentracijo glutationa in cisteina. Naraščajoče koncentracije arzenata so v kombinaciji z 1 mg Se(IV)/l negativno vplivale na rastne parametre, ta je bil najbolj opazen pri višjih koncentracijah (60 in 80 mg As/l + 1 mg Se(IV)/l), kar je sovpadalo tudi z nižanjem potencialne fotokemične učinkovitosti fotosistema II in koncentracije klorofilov ter antocianinov. Privzem arzena in selena je bil višji v korenine, kot v nadzemne dele rastlin. Prisotnost arzenata je pozitivno vplivala na privzem selena v koreninah, kar nakazuje na sinergistični učinek med elementoma. Vsebnost glutationa in cisteina se je v koreninah in nadzemnem delu rastlin višala z naraščajočo koncentracijo arzenata v kombinaciji z 1 mg Se(IV)/l.

Ključne besede

selen;arzen;Berula erecta;rastni parametri;fotokemična učinkovitost;barvila;tioli;magistrska dela;

Podatki

Jezik: Slovenski jezik
Leto izida:
Tipologija: 2.09 - Magistrsko delo
Organizacija: UM FNM - Fakulteta za naravoslovje in matematiko
Založnik: [M. Krajnc]
UDK: 581.5:582.795(043.2)
COBISS: 23923464 Povezava se bo odprla v novem oknu
Št. ogledov: 896
Št. prenosov: 156
Ocena: 0 (0 glasov)
Metapodatki: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Ostali podatki

Sekundarni jezik: Angleški jezik
Sekundarni naslov: Effect of various selenite and arsenate concentrations on Berula erecta in in vitro conditions
Sekundarni povzetek: The aim of this master thesis was to investigate the effect of various concentrations of selenite (0,01, 0,1, 1, 10 and 50 mg/l) and arsenate (20, 40, 60 and 80 mg/l) in combination of 1 mg Se (IV)/l on growth parameters, photochemical efficiency, photosynthetic pigments, anthocyanins, glutathione and cysteine content of Berula erecta in in vitro conditions. The plants were grown on a simple Murashige and Skoog (1962) medium with no growth regulators. A single trial lasted for three weeks. Low selenite concentrations (0,01, 0,1 and 1 mg/l) accelerated the growth of shoots and roots, and stimulated the formation of buds and stolons, whereas higher concentrations (10 in 50 mg Se(IV)/l) supressed the growth of plants. The concentration of 1 mg Se(IV)/l had the most stimulating effect on growth parameters; therefore it was used in interaction with arsenate. The concentration of 50 mg Se(IV)/l had a strong negative effect on the potential photochemical efficiency of photosystem II. The pigment content decreased at all selenite concentrations. With increasing selenite concentrations, the total selenium uptake increased. 1 mg Se(IV)/l was the concentration limit to which the total glutathione and cysteine content in the roots and shoots increased. At higher concentrations selenium started to act as a pro-oxidant, and consequently reduced the glutathione and cysteine concentration. Increasing concentrations of arsenate in combination of 1 mg Se(IV)/l had a negative effect on growth parameters, which was most noticeable at higher concentrations (60 and 80 mg As/l + 1 mg Se(IV)/l). This coincided with the decrease in the potential photochemical efficiency of photosystem II and the concentration of chlorophylls and anthocyanins. Selenium and arsenic uptake was higher in the roots than in the above-ground parts of the plants. The presence of arsenate had a positive effect on the selenium uptake in the roots, suggesting a synergistic effect between the elements. Increasing arsenate concentration in combination of 1 mg Se(IV)/l caused the increase of glutathione and cysteine concentrations both in the roots and in the above-ground parts of the plants.
Sekundarne ključne besede: selenium;arsenic;Berula erecta;growth parameters;photochemical efficiency;pigments;thiols;master theses;
URN: URN:SI:UM:
Vrsta dela (COBISS): Magistrsko delo/naloga
Komentar na gradivo: Univ. v Mariboru, Fak. za naravoslovje in matematiko, Oddelek za biologijo
Strani: XIII, 95 f.
ID: 10935419