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master's thesis
Pokazatelji starenja u listovima duhana (Nicotiana tabacum L.)
Zagreb: University of Zagreb, Faculty of Science, 2008. urn:nbn:hr:217:711746
Matan, Melita
University of Zagreb
Faculty of Science
Department of Biology

Institutional repository: Repository of the Faculty of Science

Cite this document

Matan, M. (2008). Pokazatelji starenja u listovima duhana (Nicotiana tabacum L.) (Master's thesis). Zagreb: University of Zagreb, Faculty of Science. Retrieved from https://urn.nsk.hr/urn:nbn:hr:217:711746

Matan, Melita. "Pokazatelji starenja u listovima duhana (Nicotiana tabacum L.)." Master's thesis, University of Zagreb, Faculty of Science, 2008. https://urn.nsk.hr/urn:nbn:hr:217:711746

Matan, Melita. "Pokazatelji starenja u listovima duhana (Nicotiana tabacum L.)." Master's thesis, University of Zagreb, Faculty of Science, 2008. https://urn.nsk.hr/urn:nbn:hr:217:711746

Matan, M. (2008). 'Pokazatelji starenja u listovima duhana (Nicotiana tabacum L.)', Master's thesis, University of Zagreb, Faculty of Science, accessed 25 August 2024, https://urn.nsk.hr/urn:nbn:hr:217:711746

Matan M. Pokazatelji starenja u listovima duhana (Nicotiana tabacum L.) [Master's thesis]. Zagreb: University of Zagreb, Faculty of Science; 2008 [cited 2024 August 25] Available at: https://urn.nsk.hr/urn:nbn:hr:217:711746

M. Matan, "Pokazatelji starenja u listovima duhana (Nicotiana tabacum L.)", Master's thesis, University of Zagreb, Faculty of Science, Zagreb, 2008. Available at: https://urn.nsk.hr/urn:nbn:hr:217:711746

Metadata
TitlePokazatelji starenja u listovima duhana (Nicotiana tabacum L.)
Title (english)Indicators of senescence in tobacco leaves (Nicotiana tabacum L.)
AuthorMelita Matan
MentorBranka Pevalek-Kozlina (mentor)
GranterUniversity of Zagreb
Faculty of Science
(Department of Biology)
Zagreb
Defense date and country2008, Croatia
Scientific / art field,
discipline and subdiscipline		NATURAL SCIENCES
Biology
Abstract
Duhan se često koristi kao modelna biljka budući je razmjerno tolerantan i široko rasprostranjen. Proces starenja obično izaziva smanjenje fotosinteze te oksidacijski stres. Istraživala sam proces prirodnog starenja u listovima starosti 14, 30, 120 i 270 dana te proces prijevremenog starenja potaknut vodikovim peroksidom (10 mM) u listovima starim 14 dana. U ovom radu praćeni su djelotvornost fotosintetskog aparata (stvaranje i utrošak kisika, sadržaji klorofila i karotenoida), strukturne promjene u stanicama lista, pokazatelji oksidacijskog stresa (sadržaji vodikovog peroksida, malondialdehida i karbonilnih grupa te oštećenje DNA) i aktivnost antioksidacijskih enzima. U svim listovima duhana došlo je do povećanog utroška kisika i smanjenja sadržaja klorofila i karotenoida sa starošću listova kao i u listovima tretiranim vodikovim peroksidom. Poludebeli prerezi listova pokazali su smanjenje kloroplasta sa starošću listova te povećanje broja plastoglobula. Pregledom ultratankih prereza listova uočen je dobro razvijen tilakoidni sustav u svim listovima osim u onima od 14 dana te povećanje plastoglobula sa starošću listova i prisutnost škrobnih zrnaca. Starenjem listova uočeni su porast vodikova peroksida, sadržaja malondialdehida i karbonila dok je u listovima tretiranim vodikovim peroksidom došlo do smanjenja sadržaja vodikovog peroksida te povećanja sadržaja malondialdehida i karbonila. Analiza jezgara stanica komet testom nije pokazala znatno oštećenje molekule DNA. Aktivnost superoksid dismutaze se povećala, a aktivnosti katalaze i peroksidaza smanjila sa starošću listova. U tretiranim listovima aktivnosti antioksidacijskih enzima su se povećale. Rezultati ovog istraživanja ukazuju na sposobnost učinkovite obrane ove biljne vrste od oštećenja uzrokovanog oksidacijskim stresom te na ulogu vodikovog peroksida kao signalne molekule.
Abstract (english)
Tobacco is often used as model plant because it is widely distributed and considered to be moderately tolerant plant species. The process of senescence is characterized by decline in photosynthesis and induction of oxidative stress. We have investigated the process of natural senescence in leaves old 14, 30, 120 and 270 days and process of artificial senescence induced by 10 mM hydrogen peroxide in leaves old 14 days. The efficiency of photosynthetic system (oxygen evolution and consumption, chlorophyll and carotenoid contents) structural changes in leaf cells, indicators of oxidative stress (contents of hydrogen peroxide, malondialdehyde and carbonyl groups as well as DNA damage) and activities of antioxidative enzymes were monitored. Chlorophylls and carotenoid contents declined while oxygen consumption increased as a result of both natural and artificially induced senescence. Number of chloroplasts decreased while that of plastoglobuls increased with senescence as evident by light microscopy. Ultrathin slices showed well developed thylakoids in all samples and increase of size and number of starch grains as well as plastoglobuls with senescence. Carbonyl and MDA contents increased with natural and artificial senescence while hydrogen peroxide showed increase and decrease with natural and artificial senescence, respectively. DNA damage evaluated by Comet test was not observed in senescent tobacco leaves. Superoxide dismutase activity increased while catalase and peroxidase activities decreased in senescent tobacco leaves. Senescence induced by hydrogen peroxide activities of all antioxidative enzymes increased. Presented results show the efficiency of antioxidative enzymes to fight oxidative stress and show the importance of hydrogen peroxide as a signal molecule.
Keywords
Keywords (english)
Languagecroatian
URN:NBNurn:nbn:hr:217:711746
Study programmeTitle: Integrated undergraduate and graduate university study of Biology and Chemistry Education; specializations in: Integrated undergraduate and graduate university study of Biology and Chemistry Education
Course: Integrated undergraduate and graduate university study of Biology and Chemistry Education
Study programme type: university
Study level: integrated undergraduate and graduate
Academic / professional title: magistar/magistra edukacije biologije i kemije (magistar/magistra edukacije biologije i kemije)
Type of resourceText
File originBorn digital
Access conditionsOpen access
Terms of useLicence In copyright icon
Created on2018-03-05 12:19:48