Učinak kadmija na fotosintezu i sadržaj sekundarnih metabolita u lišajeva Parmelia sulcata, Evernia prunastri i Flavoparmelia caperata

master's thesis

• Title (english): The impact of cadmium on photosynthesis and secondary metabolites in lichens Parmelia sulcata, Evernia prunastri and Flavoparmelia caperata
• Author: Ana Maslać
• Mentor: Mirta Tkalec (mentor)
• Committee member: Mirta Tkalec (član povjerenstva)
• Committee member: Ines Radanović (član povjerenstva)
• Committee member: Ivančica Ternjej (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2016, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Lišajevi se koriste kao uspješni bioindikatori kvalitete zraka budući da onečišćenje zraka može uzrokovati različite fiziološke promjene u lišajevima. Budući da je razina teškog metala kadmija često povećana u onečišćenom zraku cilj istraživanja je bio odrediti učinak kratkoročnog izlaganja otopini kadmija (50 mg/L) na fotosintetski aparat i sadržaj sekundarnih metabolita u lišajeva Parmelia sulcata, Evernia prunastri i Flavoparmelia caperata. Oštećenje fotosintetskog aparata procijenjeno je metodom fluorescencije klorofila a, a detekcija i kvantifikacija sekundarnih metabolita metodom tekućinske kromatografije visoke djelotvornosti. U sve tri vrste lišajeva optimalni prinos i stopa smanjenja fluorescencije nisu se razlikovali u kontrolnim uzorcima i onima tretiranim kadmijem prvi i treći dan nakon izlaganja dok je osmi dan primijećeno smanjenje vrijednosti što ukazuje na oštećenje fotosintetskog sustava. U sve tri vrste identificirani su sekundarni metaboliti specifični za tu vrstu; salazinska kiselina i atranorin u vrste P. sulcata, evernična kiselina, atranorin i kloratranorin u vrste E. prunastri te protocetrarična i usninska kiselina u vrste F. caperata. U lišajeva s listastim talusom (P. sulcata i F. caperata) izlaganih kadmiju uočena je smanjena koncentracija depsidona salazinske i protocetrarične kiseline, koji se nalaze u meduli lišaja, a povećana koncentracija depsidona atranorina i dibenzofurana usninske kiseline, uobičajenih za korteks. U lišaja s grmastim talusom (E. prunastri) nije došlo do značajnijih promjena u koncentraciji metabolita. Dobiveni rezultati pokazuju da su istraživane vrste donekle otporne na izlaganje kadmiju te da sekundarni metaboliti mogu imati ulogu u otpornosti na teške metale ali da to ovisi o njihovoj kemijskoj strukturi, dijelu talusa u kojem se nalaze i formi rasta lišajeva.

Abstract (english)

Lichens are successfully used as air quality bioindicators, due to the fact that various physiological changes in lichens can be caused by air pollution. Since the level of heavy metal cadmium is often increased in polluted air, the objective of this research was to determine the impact of short-term exposure to cadmium (50 mg/L) on photosynthetic apparatus and secondary metabolites in lichens Parmelia sulcata, Evernia prunastri and Flavoparmelia caperata. Chlorophyll fluorescence was used to estimate photosynthetic damage, while detection and quantification of secondary metabolites was determined by high performance liquid chromatography. In all three species, optimum quantum yield and fluorescence decrease ratio did not show differences between cadmium-treated lichens and corresponding controls after first and third day of exposure. On the eight day decreased values were observed, that can indicate damage of photosynthetic apparatus. Lichen substances typical for particular species were detected: salazinic acid and atranorin in P. sulcata; evernic acid, atranorin and chloroatranorin in E. prunastri; and protocetraric acid and usnic acid in F. caperata. In foliose lichens (P. sulcata and F. caperata) a decreased content of medullary depsidones salazinic and protocetraric acid, but increased content of cortical depsides atranorin and dibenzofurane usnic acid was observed in cadmium-treated lichens. In the fruticose lichen (E. prunastri) no significant changes were found in metabolites content. Results show that investigated species are partly resistant to cadmium-exposure and that secondary metabolites could have a role in heavy metal tolerance. However, the tolerance could depend on metabolites chemical structure, lichen growth form and part of the thallus where metabolites are deposited.

• Keywords: kadmij; onečišćenje zraka; lišajevi; fotosinteza; sekundarni metaboliti
• Keywords (english): cadmium; air pollution; lichens; photosynthesis; secondary metabolites
• Language: croatian
• URN:NBN: urn:nbn:hr:217:398172
• Study programme: Title: Biology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra edukacije biologije (magistar/magistra edukacije biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-05-17 09:28:13