Fitotoksični učinci nanočestica srebra stabiliziranih različitim omotačima na fiziološke procese u odraslim biljkama duhana (Nicotiana tabacum L.)

doctoral thesis

• Title (english): Phytotoxic effects of silver nanoparticles stabilized with different coatings on physiological processes in adult tobacco plants (Nicotiana tabacum l.)
• Author: Karla Košpić
• Mentor: Biljana Balen (mentor)
• Committee member: Petra Peharec Štefanić (predsjednik povjerenstva)
• Committee member: Željka Vidaković-Cifrek (član povjerenstva)
• Committee member: Daniel Mark Lyons (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2023-11-28, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology
• Universal decimal classification (UDC): 577 - Biochemistry. Molecular biology. Biophysics

Abstract

Nanočestice srebra (AgNP) bilježe sve veću primjenu zbog čega su rastući ekološki problem. Kako bi se spriječila njihova agregacija i disocijacija pri sintezi im se dodaju stabilizirajući omotači koji mogu modulirati toksični učinak. U ovom radu istražen je utjecaj AgNP stabiliziranih omotačima polivinilpirolidon (PVP) i cetiltrimetilamonij bromid (CTAB) na fiziološke procese u korijenu i listu biljaka duhana. Napravljena je i usporedna analiza izlaganjem AgNO3 i kombiniranim tretmanima AgNP ili AgNO3 s cisteinom. Oba organa pokazala su mobilizaciju antioksidacijskog sustava koja je bila izraženija nakon tretmana s oba tipa AgNP u odnosu na AgNO3. Jači antioksidacijski odgovor zabilježen je u listu u odnosu na korijen, s aktivacijom određenih komponenti specifičnih za biljni organ i tip omotača. Smanjenje fotosintetske učinkovitosti praćeno je smanjenom ekspresijom fotosintetskih proteina, a promjene u ekspresiji pokazali su i proteini uključeni u odgovor na stres i sintezu proteina. Cistein je ublažio učinak svih tretmana, pokazujući da toksičnost AgNP djelomično potječe od iona Ag+. Veća toksičnost AgNP-CTAB u usporedbi s AgNP-PVP pokazuje da fizikalno-kemijska svojstva omotača moduliraju toksične učinke.

Abstract (english)

With increasing silver nanoparticles (AgNP) use comes a growing concern for the environment. To prevent aggregation and dissociation, stabilisers are used in their synthesis that can modulate their toxic effects. In this work, effects of AgNP stabilised with polyvinylpyrrolidone (PVP) and cetyltrimethylammonium bromide (CTAB) on physiological processes in roots and leaves of tobacco plants were investigated. A comparative analysis included treatments with AgNO3 and combined treatments of AgNP or AgNO3 with cysteine. In both organs, mobilisation of antioxidant system was more pronounced after both types of AgNP treatments compared with AgNO3. A stronger antioxidant response was observed in leaf compared with root, while activation of specific components was organ- and coating-dependent. Reduced photosynthetic efficiency correlated with decreased expression of photosynthetic proteins, while proteins involved in stress response and protein synthesis also showed changes in expression. Cysteine attenuated effects of all treatments, suggesting that AgNP toxicity is partly due to Ag+ ions. The higher toxicity of AgNP-CTAB compared with AgNP-PVP suggests that coating physicochemical properties play a role in modulating the toxic effects.

• Keywords: Nicotiana tabacum; L. nanočestice srebra; fitotoksičnost; stabilizirajući omotači; oksidacijski stres; fotosinteza; ekspresija proteina
• Keywords (english): Nicotiana tabacum; L. silver nanoparticles; phytotoxicity; stabilising coatings; oxidative stress; photosynthesis; protein expression
• Language: croatian
• URN:NBN: urn:nbn:hr:217:949744
• Promotion: 2024
• Project: Number: IP-2014-09-6488; Title: Fitotoksičnost nanosrebra: mehanizmi akcije i interakcije u stanicama duhana; Title: Nanosilver phytotoxicity: mechanisms of action and interaction in tobacco cells; Acronym: NanoPhytoTox; Leader: Biljana Balen; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Doctoral study; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti u području prirodnih znanosti (doktor/doktorica znanosti u području prirodnih znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2024-11-28
• Created on: 2024-01-11 12:27:35