undergraduate thesis
Plant lipoxygenases and their physiological function

Magdalena Grgić (2016)
Sveučilište Josipa Jurja Strossmayera u Osijeku
Odjel za biologiju
Metadata
TitleBiljne lipoksigenaze i njihova fiziološka uloga
AuthorMagdalena Grgić
Mentor(s)Elizabeta Has Schon (thesis advisor)
Abstract
Selen kao mikronutrijent u biljkama može imati dvojno djelovanje. U malim količinama djeluje antioksidacijski, potičući aktivnost mnogih enzima koji sudjeluju u odgovoru na oksidacijski stres, dok u velikim količinama djeluje prooksidacijski i toksično. Cilj ovog rada bio je odrediti utjecaj različitih koncentracija selena u obliku selenita i selenata na ekspresiju lipoksigenaza (LOX) i razinu lipidne peroksidacije (LPO) u izdancima pšenice (Triticum aestivum L.). LOX su enzimi koji u biljci kataliziraju stvaranje hidroperoksida polinezasićenih masnih kiselina iz kojih daljnjim metaboličkim putevima nastaju oksilipini. Uloga oksilipina u stanici je značajna jer ih biljke sintetiziraju tijekom stresa, napada patogena ili biljojeda. Kada je biljka izložena stresu, količina LOX-a u biljci raste. U ovom istraživanju pšenica je tretirana različitim koncentracijama selena (0.01 mg × kg-1, 0.1 mg × kg-1 i 1 mg × kg-1) u obliku selenita i selenata, te su nakon 15 dana u izdancima mjereni ekspresija LOX enzima i reaktivnih supstanci tiobarbiturne kiseline (TBARS) kao pokazatelja razine LPO. Kod svih tretmana selenom, ekspresija LOX-a u izdancima bila je manja u odnosu na kontrolnu skupinu što ukazuje na negativni učinak selena na ekspresiju ovog enzima. Budući da količine TBARS-a u izdancima pšenice kod različitih tretmana nisu bile značajno veće u odnosu na kontrolu, možemo zaključiti da pri navedenim koncentracijama selen ni u jednom obliku ne izaziva pojačani oksidacijski stres u biljci.
Keywordsplant lypoxigenases lipid peroxidation wheat selenium
Parallel title (English)Plant lipoxygenases and their physiological function
Committee MembersElizabeta Has Schon (committee chairperson)
GranterSveučilište Josipa Jurja Strossmayera u Osijeku
Odjel za biologiju
PlaceOsijek
StateCroatia
Scientific field, discipline, subdisciplineNATURAL SCIENCES
Biology
Study programme typeuniversity
Study levelundergraduate
Study programmeUndergraduate University Study Programme in Biology (Bachelor of Science)
Academic title abbreviationuniv.bacc.biol.
Genreundergraduate thesis
Language Croatian
Defense date2016-09-26
Parallel abstract (English)
As a micronutrient, selenium has a dual role in plants. At lower concentrations it acts as an antioxidant and stimulates oxidative stress response enzymes, whereas in higher concentrations it acts as a pro-oxidant and it is toxic. The aim of this study was to determine the effects of different forms and concentractions of selenium on the expression of plant lypoxigenases (LOX) and lipid peroxidation levels (LPO) in the wheat shoots (Triticum aestivum L.). LOX enzymes catalyze the formation of unsaturated fatty acid hydroperoxide from polyunsaturated fatty acids, from which in further metabolic pathways oxylipins are formed. Oxylipins have significant role in plants because they are synthesised in response to stress, pathogen or herbivore attack. In plants subjected to stress LOX levels are increased. In this research, wheat was treated with different concentrations (0.01 mg × kg-1, 0.1 mg × kg-1 i 1 mg × kg-1) of selenite or selenate and after 15 days, expression of LOX and LPO levels, expressed as Thiobarbituric Acid Reactive Substances (TBARS), in shoots were measured. All plants treated with both selenium forms, selenite and selenate, showed decreased levels of LOX with respect to control, indicating negative correlation between selenium treatment and LOX expression. Since the level of TBARS in shoots were not statistically different compared to control, we can conclude that selenium in neither of its forms and applied concentrations induced stress response in plants.
Parallel keywords (Croatian)biljne lipoksigenaze lipidna peroksidacija pšenica selen
Resource typetext
Access conditionOpen access
Terms of usehttp://rightsstatements.org/vocab/InC/1.0/
URN:NBNhttps://urn.nsk.hr/urn:nbn:hr:181:515594
CommitterVesna Radman Meic