Utjecaj niskih temperatura na sadržaj specijaliziranih metabolita u klijancima raštike (Brassica oleracea var. acephala)

master's thesis

• Title (english): Effects of low-temperature stress on the level of specialized metabolites in kale (Brassica oleracea var. acephala) sprouts
• Author: Stjepana Fistanić
• Mentor: Dunja Šamec (mentor)
• Mentor: Sandra Radić Brkanac (mentor)
• Committee member: Sandra Radić Brkanac (predsjednik povjerenstva)
• Committee member: Ines Radanović (član povjerenstva)
• Committee member: Iva Juranović Cindrić (član povjerenstva)
• Committee member: Vesna Petrović Peroković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2019-02-22, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Klimatske promjene izazivaju češće periode ekstremnih temperatura koje značajno utječu na poljoprivrednu proizvodnju. Neke su biljne vrste otpornije na temperaturne ekstreme, a jedna od njih je i raštika (Brassica oleracea var. acephala). Stoga, cilj ovog rada je praćenje odgovora klijanaca raštike na stres izazvan niskim temperaturama kroz tri uzgoja (I., II., III.). Klijanci raštike stari tri dana izloženi su temperaturi pothlađivanja (8 ºC) (24 h: I., II. i III. uzgoj) te smrzavanja (−8 ºC) (24 h: u II. te 4 h u III. uzgoju) u usporedbi s kontrolom (21 ºC). Sniženje temperature usporilo je fiziološke procese te su klijanci izloženi nižim temperaturama imali kraće korijenje te posljedično manji prinos. Stres se odrazio i na biokemijske promjene te je kod klijanaca izloženih nižim temperaturama izmjerena viša razina prolina kao markera stresa te niža razina klorofila. Izloženost temperaturama pothlađivanja nije značajno utjecala na razinu ukupnih polifenola, flavonoida, fenolnih kiselina te antioksidacijsku aktivnost, dok je izloženost temperaturi smrzavanja utjecala na smanjenje ukupnih polifenola i fenolnih kiselina kod drugog uzgoja gdje je duljina izlaganja toj temperaturi bila 24 h. Izlaganje temperaturi smrzavanja izazvalo je i smanjenje količine ukupnih karotenoida, dok razina glukozinolata nije pokazala jasan trend s obzirom na temperaturu i različito vrijeme uzgoja.

Abstract (english)

Climate change induces more frequent periods of extreme temperatures which significantly influence agricultural production. Some plant species, including kale (Brassica oleracea var. acephala), are more resistant to temperature extremes than others. Therefore, the purpose of this study is to monitor the responses of kale sprouts to low temperature stress trought three experiments (I., II., III.). Three days old plants were exposed to chilling (8º C) (24 h at I., II., III.) and freezing (−8 ºC) (24 h at II., 4h at III.) stress in comparison with control (21 ºC). Lowering the temperature slowed the physiological processes and the sprouts exposed to lower temperatures had shorter roots and consequently lower yield. The stress also reflected in biochemical changes - the higher level of proline, the stress marker, and the lower level of chlorophyll were measured in the sprouts exposed to lower temperatures. The exposure to the chilling temperature did not significantly influence the level of the total polyphenols, flavonoids, phenolic acids or antioxidant activity, while the exposure to the freezing temperature resulted in lowering the level of the total polyphenols and phenolic acids in the second cultivation in which the length of exposure to that temperature was 24 h. The exposure to the freezing temperature caused the total amount of carotenoids to decrease, while the level of the glucosinolates did not show a clear trend with regard to temperature and the time of cultivation.

• Keywords: Brassicaceae; raštika; prolin; specijalizirani metaboliti; klorofil; karotenoidi; antioksidacijska aktivnost
• Keywords (english): Brassicaceae; kale; proline; specialized matabolites; chlorophyll; carotenoids; antioxidant activity
• Language: croatian
• URN:NBN: urn:nbn:hr:217:879819
• Study programme: Title: 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 resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2020-02-22
• Created on: 2019-03-26 09:16:23