Procjena tolerancije varijeteta divljeg kupusa (Brassica incana) na čimbenike abiotičkog stresa

master's thesis

• Title (english): Evaluation of wild cabbage (Brassica incana) varieties tolerance to abiotic stress factors
• Author: Krunoslav Baotić
• Mentor: Branka Salopek Sondi (mentor)
• Mentor: Martina Šeruga Musić (komentor)
• Committee member: Martina Šeruga Musić (predsjednik povjerenstva)
• Committee member: Sandra Radić Brkanac (član povjerenstva)
• Committee member: Sunčica Bosak (član povjerenstva)
• Committee member: Maja Matulić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2023-09-22, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Klimatske promjene i s njima često povezan abiotički stres imaju vrlo značajan utjecaj na rast i razvoj
biljaka. Za suočavanje s nepovoljnim uvjetima u okolišu biljke koriste različite strategije i mehanizme
kako bi smanjile njihov negativan učinak. U ovom istraţivanju ispitano je šest varijeteta divljih
kupusa (Brassica incana) koji prirodno rastu na liticama hrvatskih otoka u izuzetno nepovoljnim
uvjetima. Klijanci uzgajani na 1 %-tnom agaru bili su podvrgnuti solnom (100 mM NaCl),
osmotskom (200 mM manitol) i temperaturnom (maksimum na 40 °C) stresu, te kombinaciji
navedenih vrsta stresova. Dobiveni rezultati usporeĎeni su s tri varijeteta, morfološki vrlo slične,
raštike (Brassica acephala var. capitata) koji su tretirani na isti način kao i divlji kupus. Odgovor
biljaka na stres pratio sam testom inhibicije rasta te mjerenjem biokemijskih markera stresa. Na
osnovu dobivenih rezultata odabrao sam dva varijeteta divljeg kupusa i dva varijeteta raštike na
kojima sam dodatno, pomoću metode qPCR, pratio ekspresiju gena (NAC041, NAC084 i DREB2A)
uključenih u odgovoru biljaka na stres. Temperaturni tretman je kod mjerenja biomase imao najmanji
utjecaj na rast i razvoj, dok je najveće smanjenje uzrokovao osmotski stres. Kod divljeg kupusa je na
svim tretmanima, a posebno na solnom i osmotskom, zapaţeno povećanje sadrţaja prolina. Različiti
varijeteti divljih kupusa pokazali su različite antioksidativne odgovore na svakom tretmanu, dok se
razina malondialdehida (MDA) u najviše slučajeva povećavala kod solnog stresa. Povećana
akumulacija ukupnih fenola u divljih kupusa zabiljeţena je kod solnog i osmotskog stresa. Tretmani
koji su uključivali temperaturu su u najvećem broju slučajeva uzrokovali povećanu ekspresiju gena
NAC, a ekspresija gena DREB2A bila je zabiljeţena na svim tretmanima što opravdava njegovu ulogu
u otpornosti na stres.

Abstract (english)

Climate changes and the often associated abiotic stress have a very significant impact on the growth
and development of plants. To cope with adverse environmental conditions, plants use different
strategies and mechanisms to reduce their impact. In this research, six varieties of wild cabbage
(Brassica incana) that grow naturally on the cliffs of Croatian islands in extremely unfavorable
conditions were examined. Seedlings grown on 1% agar were subjected to salt (100 mM NaCl),
osmotic (200 mM mannitol) and temperature (maximum at 40 °C) stress, as well as a combination of
these types of stress. The obtained results were compared with three varieties, morphologically very
similar, kale (Brassica acephala var. capitata) which were treated in the same way as wild cabbage.
I monitored the plants response to stress with a growth inhibition test and by measuring biochemical
markers of stress. Based on the obtained results, I selected two varieties of wild cabbage and two
varieties of kale on which I additionally monitored the expression of the stress responsive genes
(NAC041, NAC084 and DREB2A) by using PCR. Temperature treatment had the least impact on
biomass measurement, while osmotic stress caused the strongest reduction. In wild cabbage, an
increase in proline content was observed in all treatments, particularly salinity and osmotic stress.
Different varieties of wild cabbage showed different antioxidative responses to each treatment, while
the level of malondialdehyde (MDA) increased in most cases under salt stress. Increased
accumulation of total phenols in wild cabbage was recorded under salt and osmotic stress. Treatments
that included temperature caused increased NAC gene expression in most cases, and DREB2A gene
expression was recorded in all treatments, which justifies its role in stress resistance.

• Keywords: biokemijski markeri; solni stres; osmotski stres; temperaturni stres; kombinirani abiotički stres; ekspresije gena
• Keywords (english): biochemical markers; salinity stress; osmotic stress; heat stress; combined abiotic stress; gene expression
• Language: croatian
• URN:NBN: urn:nbn:hr:217:501765
• Study programme: Title: Molecular Biology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra molekularne biologije (magistar/magistra molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2024-09-22
• Created on: 2023-10-17 11:48:26