Uloga molekula miRNA u odgovoru biljaka na abiotički stres

undergraduate thesis

• Title (english): Role of miRNAs in abiotic stress responses in plants
• Author: Juraj Ulaga
• Mentor: Željka Vidaković Cifrek (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2022-09-23, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Abiotički stres uzrokovan okolišnim uvjetima poput suše, povišenog saliniteta, ekstremnih
temperatura ili intenzivnog UV zračenja ima negativan utjecaj na rast i razvoj biljaka. Brojni
mehanizmi odgovora na abiotički stres, uključujući regulaciju ekspresije gena posredovanu
molekulama miRNA, omogućuju biljkama prevladavanje nepovoljnih okolišnih uvjeta.
Molekule miRNA su male nekodirajuće molekule RNA koje reguliraju ekspresiju gena
uglavnom na posttranskripcijskoj razini. Biosinteza molekula miRNA uključuje transkripciju
gena MIR, procesiranje prekursora molekula miRNA u zrele molekule miRNA pomoću enzima
DCL1, nanošenje molekule miRNA na proteine AGO i sastavljanje kompleksa miRISC. Na
temelju komplementarnosti s ciljanom sekvencom, kompleks miRISC utišava ekspresiju
ciljanih gena cijepanjem ili inhibicijom translacije transkripata. Molekule miRNA imaju važnu
regulatornu ulogu u biljnom razvoju i interakcijama biljaka s okolišem uključujući razvojnu
plastičnost, odgovor na biotički i abiotički stres te interakcije sa simbiontima i parazitima.
Molekule miRNA inducirane abiotičkim stresom utišavaju ekspresiju negativnih regulatora u
okviru odgovora na stres dok akumulaciju pozitivnih regulatora omogućuju molekule miRNA
inhibirane abiotičkim stresom. U ovom radu je opisan značaj molekula miRNA povezanih s
oksidacijskim, toplinskim, osmotskim i svjetlosnim stresom te nedostatkom vode.

Abstract (english)

Abiotic stress caused by environmental conditions such as drought, increased salinity, extreme
temperatures or intense UV radiation has a negative impact on plant growth and development.
Numerous abiotic stress response mechanisms, including regulation of gene expression
mediated by miRNA molecules, enable plants to overcome adverse environmental conditions.
Micro RNA (miRNA) molecules are small non-coding RNA molecules that regulate gene
expression mainly at the post-transcriptional level. Biosynthesis of miRNA molecules involves
transcription of MIR genes, processing of miRNA precursor molecules into mature miRNA
molecules by the enzyme DCL1 and loading of the mature miRNAs into AGO proteins to form
the miRNA-induced silencing complex (miRISC). Based on complementarity with the target
sequence, the miRISC silences the expression of target genes by cleaving or inhibiting the
translation of transcripts. miRNA molecules play an important regulatory roles in plant
development and plant - environment interactions, including developmental plasticity, abiotic
and biotic stress responses and interactions with symbionts and parasites. Stress-induced
miRNA molecules downregulate the expression of negative regulators of stress tolerance, while
stress-inhibited miRNA molecules enable the accumulation of positive regulators. This paper
describes the significance of miRNA molecules associated with oxidative, heat, osmotic and
light stress and water deficiency.

• Keywords: apscizinska kiselina; auksin; nedostatak vode; oksidacijski stres; ROS; toplinski stres
• Keywords (english): abscisic acid; auxin; drought; heat stress; oxidative stress; ROS
• Language: croatian
• URN:NBN: urn:nbn:hr:217:798137
• Study programme: Title: Molecular Biology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-10-12 09:17:00