Odgovor uročnjaka (Arabidopsis thaliana (L.) Heynh.) s promijenjenom ekspresijom gena BPM i DMS3 na toplinski stres

doctoral thesis

• Title (english): Response of Arabidopsis thaliana (L.) Heynh. with modified BPM and DMS3 gene expression to heat stress
• Author: Sandra Vitko
• Mentor: Željka Vidaković-Cifrek (mentor)
• Committee member: Mirta Tkalec (predsjednik povjerenstva)
• Committee member: Nataša Bauer (član povjerenstva)
• Committee member: Tatjana Prebeg (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2024, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology
• Universal decimal classification (UDC): 577 - Biochemistry. Molecular biology. Biophysics

Abstract

Proteini BPM i DMS3 sudjeluju u regulaciji rasta i razvoja te prilagodbi biljaka na okolišne
uvjete. Učinak toplinskog tretmana istražen je u biljaka uročnjaka s prekomjernom (oeBPM1 i
oeDMS3) i smanjenom (amiR-bpm i dms3-1) ekspresijom tih proteina te biljaka divljeg tipa.
Fenotipizacijom je dokazan smanjeni rast linija oeBPM1 i dms3-1 u kontrolnim uvjetima, a
toplinski tretman uzrokovao je inhibiciju rasta u divljeg tipa te linija oeDMS3, oeBPM1 i
amiR-bpm. U liniji dms3-1 tretiranoj u kasnijem razvojnom stadiju zabilježena je povećana
stopa rasta. Sve linije tretirane u stadiju klijanaca akumulirale su protein HSP90, no indukcija
HSP70 ovisila je o genskoj pozadini biljaka. U linijama oeBPM1 i amiR-bpm primijećeni su
oprečni odgovori na stres – u prvoj liniji je zabilježena smanjena fotosintetska učinkovitost, a
u drugoj povišena aktivnost antioksidacijskih enzima. U liniji oeDMS3 izmjerena je povišena
aktivnost peroksidaza, a linija dms3-1 pokazala je veću osjetljivost fotosinteze unatoč
povećanju sadržaja prolina i aktivnosti katalaze. Dobiveni rezultati ukazuju da promijenjena
ekspresija gena BPM nema jednoznačnu ulogu u termotoleranciji, ali da je za otpornost u stadiju
klijanaca potrebna prisutnost funkcionalnog proteina DMS3.

Abstract (english)

Proteins BPM and DMS3 participate in the regulation of growth and development, and
adaptation of plants to environmental conditions. The effects of heat treatment were studied in
Arabidopsis thaliana plants with overexpression (oeBPM1 and oeDMS3) and downregulation
(amiR-bpm and dms3-1) of these proteins, as well as in wild-type plants. Phenotyping of plants
showed reduced growth of oeBPM1 and dms3-1 lines under control conditions, while heat
treatment caused growth inhibition of wild type and oeDMS3, oeBPM1 and amiR-bpm lines.
The dms3-1 line treated at a later developmental stage showed an increased growth rate. All
lines treated at the seedling stage accumulated HSP90 protein, but the induction of HSP70
depended on the genetic background of the plants. In oeBPM1 and amiR-bpm lines, opposite
responses to stress were observed – reduced photosynthetic efficiency in the former and
increased antioxidant enzyme activity in the latter. Increased peroxidase activity was measured
in oeDMS3 line, while dms3-1 line showed photosynthetic sensitivity despite higher proline
content and catalase activity. The results suggest that the altered expression of BPM genes does
not have a straightforward role in thermotolerance, but the presence of a functional DMS3
protein is essential for tolerance in the seedling stage.

• Keywords: MATH-BTB; RdDM; fenotipizacija; JIP-test; antioksidacijski sustav
• Keywords (english): MATH-BTB; RdDM; plant phenotyping; JIP-test; antioxidant system
• Language: croatian
• URN:NBN: urn:nbn:hr:217:666656
• Promotion: 2024
• Project: Number: IP-2016-06-6229; Title: MATH-BTB proteini kao regulatori transkripcije i RNA posredovane metilacije DNA u biljnom razvitku; Acronym: PHYTOMETHDEV; Leader: Dunja Leljak-Levanić; Jurisdiction: Croatia; Funder: Hrvatska zaklada za znanost; Funding stream: Research Projects
• Project: Number: 284443; Title: European Plant Phenotyping Network; Acronym: EPPN; Leader: Željka Vidaković Cifrek; Jurisdiction: eu; Funder: EC; Funding stream: FP7
• 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: Open access
• Created on: 2024-05-07 08:58:31