Utjecaj mikroplastike na rast i proces fotosinteze u vodenoj leći (Lemna minor)

master's thesis

• Title (english): The effects of microplastics on the growth and photosynthesis of Lemna minor
• Author: Ana Matešković
• Mentor: Mirta Tkalec (mentor)
• Mentor: Sandra Vitko (komentor)
• Committee member: Mirta Tkalec (predsjednik povjerenstva)
• Committee member: Biljana Balen (član povjerenstva)
• Committee member: Željka Vidaković-Cifrek (član povjerenstva)
• Committee member: Antun Alegro (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2024-09-19, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Čestice mikroplastike (MP), kao otpad i produkti razgradnje veće plastike, rašireni su
zagađivači s potencijalnim učinkom na okoliš. Polistiren (PS) i poli(metil metakrilat)
(PMMA) dvije su vrste plastike koje se naširoko koriste u industriji i mogu se nakupljati
u okolišu, stoga je važno istražiti njihove moguće učinke na biljke. U ovom radu
istraživala sam učinke različitih koncentracija (10, 50 i 100 mg L -1) PS- i PMMA-MP
na rast i fotosintezu vodene leće (Lemna minor L.), modelnog organizma koji se koristi
za ekotoksikološka istraživanja i fitoremedijaciju. Izlaganje biljaka PS-MP je uzrokovalo
povećanje površine i broja frondova, dok je izlaganje PMMA-MP, osobito u najvišoj
koncentraciji, uzrokovalo smanjenje. Međutim, te promjene nisu bile statistički
značajne. Nijedna vrsta MP nije imala značajan učinak na maksimalni kvantni prinos
PSII (Fv/Fm), iako je indeks fotosintetske učinkovitosti (PIABS) bio malo viši u biljaka
tretiranih s PS-MP, u odnosu na PMMA-MP. Tretman s PMMA-MP je doveo i do većeg
smanjenja udjela pigmenta, posebice klorofila a, dok su niže koncentracije PS-MP
imale pozitivan učinak na sadržaj klorofila a, klorofila b i karotenoida u usporedbi s
kontrolom. Obje vrste MP smanjile su ekspresiju proteina RuBisCO, pri čemu je
PMMA-MP imala izraženiji učinak. Zaključno, iako obje vrste mikroplastike utječu na
fiziologiju biljaka, čini se da je PMMA-MP štetnija za vodenu leću, te je preporučljivo
nastaviti s istraživanjem učinaka i mogućih obrambenih mehanizama biljaka.

Abstract (english)

Microplastic particles (MPs), as waste and degradation products of larger plastics, are
widespread pollutants with potential environmental impact. Polystyrene (PS) and
poly(methyl methacrylate) (PMMA) plastics are widely used in industry and can
accumulate in the environment, so it is important to investigate their possible effects
on plants. In this thesis, I investigated the effects of different concentrations (10, 50
and 100 mg L-1) of PS- and PMMA-MPs on the growth and photosynthesis of common
duckweed (Lemna minor L.), a model organism used for ecotoxicological research and
phytoremediation. PS-MPs caused an increase in the number of fronds and total area,
while PMMA-MPs, particularly at the highest concentration, caused a decrease.
However, these changes were not statistically significant. Neither type of MPs had a
significant effect on the maximum quantum yield of PSII (Fv/Fm), although the
photosynthetic performance index (PIABS) was slightly higher for the PS-MP treatments
than for PMMA-MPs. PMMA-MPs also led to a greater reduction in pigment content,
especially chlorophyll a, while lower concentrations of PS-MP appeared to have a
positive effect on the content of chlorophyll a, chlorophyll b and carotenoids compared
to the control. Both types of MPs reduced the expression of RuBisCO protein, with
PMMA-MPs having a more pronounced impact. In conclusion, although both MPs
affected plant physiology, PMMA-MPs appear to be more harmful to L. minor than PSMPs,
and it is advisable to continue research into its effects and possible plant defense
mechanisms.

• Keywords: PMMA; PS; RuBisCO; pigmenti; JIP-test; broj i površina frondova
• Keywords (english): PMMA; PS; RuBisCO; pigments; JIP-test; frond number and area
• Language: english
• URN:NBN: urn:nbn:hr:217:604681
• Project: Number: IP-2022-10-3824; Title: Interaktivni učinci mikroplastike i nanosrebra na kopnene i vodene biljke i alge; Title: MIcroplastic and Nanosilver InteractiONs in terrestrial and freshwater plants and algae; Acronym: MINION; Leader: Biljana Balen; Jurisdiction: Croatia; Funder: Hrvatska zaklada za znanost; Funding stream: Research Projects
• Study programme: Title: Molecular Biology-University graduate programme; Study programme type: university; Study level: graduate; Academic / professional title: sveučilišni/a magistar/magistra molekularne biologije (sveučilišni/a magistar/magistra molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-10-03 10:16:03