Utjecaj nanočestica srebra na pojavu oksidacijskog stresa i ekspresiju proteina u klijancima duhana (Nicotiana tabacum)

master's thesis

• Title (english): The effect of silver nanoparticles on oxidative stress appearance and protein expression in tobacco seedlings (Nicotiana tabacum)
• Author: Renata Biba
• Mentor: Biljana Balen (mentor)
• Committee member: Biljana Balen (predsjednik povjerenstva)
• Committee member: Ines Radanović (član povjerenstva)
• Committee member: Vesna Petrović Peroković (član povjerenstva)
• Committee member: Draginja Mrvoš-Sermek (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2016-07-13, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Nanočestice srebra (AgNP) odlično su protubakterijsko i protugljivično sredstvo i moguće ih je naći u brojnim potrošačkim proizvodima. Zbog potencijalne toksičnosti trenutno su u središtu mnogih istraživanja s ciljem utvrđivanja opasnosti za ekološke sustave i zdravlje ljudi. U ovom je radu istražen utjecaj AgNP na klijance duhana (Nicotiana tabacum), koji je uspoređen s utjecajem ionskog srebra (AgNO3) istih koncentracija. Toksičnost AgNP zabilježena je pri visokim koncentracijama, dok je AgNO3 imao štetno djelovanje i pri nižim koncentracijama. Izmjereni porast razine reaktivnih oblika kisika ukazao je na pojavu oksidacijskog stresa, a promjene u razini malondialdehida i proteinskih karbonila pokazale su oštećenja biološki važnih molekula. Oba oblika srebra uzrokovala su oštećenje molekule DNA, što je bilo izraženije u tretmanima s AgNO3. Antioksidacijski enzimi pokazali su promjenu u aktivnosti i ekspresiji; aktivnost SOD i APX se povećala, a PPX i CAT smanjila u svim tretmanima s AgNP i AgNO3. Došlo je i do promjene u proteinskoj slici, s naglaskom na pojačanoj ekspresiji proteina stresa Hsp70. Rezultati su pokazali da AgNO3 ima jači toksični utjecaj na biljke od AgNP, ali da i AgNP pri povećanim koncentracijama uzrokuju oksidacijski stres i utječu na ekspresiju proteina, zbog čega predstavljaju moguću opasnost za okoliš.

Abstract (english)

Silver nanoparticles (AgNP) are excellent antibacterial and antifungal agents found in various consumer products. Due to their potential toxicity numerous studies are being conducted to determine whether they pose a threat to ecosystems and human health. In this research, the effects of AgNP on tobacco seedlings (Nicotiana tabacum) were analysed and compared with the effects of ionic silver (AgNO3) of the same concentrations. AgNP was toxic when applied in higher concentrations, while AgNO3 showed harmful effects even in lower concentrations. The measured increase of reactive oxygen species indicated appearance of oxidative stress, which was proven by the increase in contents of malondialdehyde and protein carbonyls. Both silver forms caused damage to DNA molecules, which was more pronounced in AgNO3 treatments. Antioxidative enzymes showed a change in activity and expression; the activity of SOD and APX increased, while PPX and CAT activity decreased in all treatments with AgNP and AgNO3. Change in protein patterns was also observed, with emphasis on the expression of stress protein Hsp70. Results indicate that AgNO3 is more toxic for plants than AgNP; however, higher AgNP concentrations also induce oxidative stress and affect protein expression, making them potential environmental hazards.

• Keywords: reaktivni oblici kisika; lipidna peroksidacija; proteinski karbonili; oštećenje DNA; antioksidacijski enzimi; proteini stresa
• Keywords (english): reactive oxygen species; lipid peroxidation; protein carbonyls; DNA damage; antioxidative enzymes; stress proteins
• Language: croatian
• URN:NBN: urn:nbn:hr:217:022149
• 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
• Created on: 2017-04-25 10:10:55