Učinak biljnih hormona stresa na klijance kineskog kupusa (Brassica rapa L. ssp. pekinensis)

master's thesis

• Title (english): Plant stress hormones effect on the Chinese cabbage seedlings (Brassica rapa L. ssp. pekinensis)
• Author: Iva Janković
• Mentor: Branka Salopek Sondi (mentor)
• Mentor: Biljana Balen (mentor)
• Committee member: Biljana Balen (predsjednik povjerenstva)
• Committee member: Branka Salopek Sondi (član povjerenstva)
• Committee member: Sandra Radić Brkanac (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2012-02-14, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Biljni hormoni auksini neophodni su u regulaciji biljnog razvitka kao i odgovoru biljaka na čimbenike stresa. Auksini se u biljnom tkivu pojavljuju slobodni (aktivne forme) ili konjugirani s aminokiselinama i šećerima (skladišne i transportne forme). Iako precizni mehanizam održavanja homeostaze auksina još nije razjašnjen, pretpostavlja se da glavnu ulogu imaju procesi konjugacije te hidrolize konjugiranih auksina po potrebi (pomoću enzima auksin-amidohidrolaza). Da bismo dobili uvid u interakcije hormona stresa i auksinskog metabolizma, u ovom radu istraţen je učinak hormona stresa: salicilne kiseline (SA), jasmonske kiseline (JA) i apscizinske kiseline (ABA) na klijance kineskog kupusa (Brassica rapa L. ssp. pekinensis). Koristeći biotest inhibicije korijena in vivo utvrđeno je da hormoni stresa djeluju inhibitorno na rast korijena uglavnom ovisno o koncentraciji. Na genskoj razini je metodom lančane reakcije polimerazom u stvarnom vremenu utvrđeno stimulativno djelovanje JA i SA na ekspresiju transkripta za auksin-amidohidrolazu BrILL2, dok je ABA djelovala inhibitorno. Spektrofotometrijskim metodama izmjereno je oksidacijsko stanje klijanaca te se pokazalo da ne dolazi do značajnog oksidacijskog stresa uslijed tretmana hormonima stresa.

Abstract (english)

Plant hormones auxins play important role in regulation of plant development as well as plant response to stress. Auxins can be found in plants as free forms (active forms), and conjugated with amino acids or sugars (storage and transport forms). Although the precise mechanism of auxin homeostasis is not fully discovered, it is assumed that their homeostasis is regulated by processes of conjugation, and hydrolysis upon tissue demand (which is accomplished by auxin amidohydrolases enzymes). In order to gain information about influence of stress hormones on the auxin homeostasis, the effect of stress hormones: salicylic acid (SA), jasmonic acid (JA), and abscisic acid (ABA) was investigated on the Chinese cabbage seedlings (Brassica rapa L. ssp. pekinensis). Inhibition of root growth upon treatment with stress hormones was identified in vivo, mostly in a dose dependent manner, using root growth bioassay. An expression level of auxin amidohydrolase BrILL2 transcript upon treatments was examined by RT-PCR. JA and SA caused up regulation, while ABA caused down regulation of BrILL2 transcript expression. Finally, oxidation status of Chinese cabbage seedlings upon treatments was discovered using spectrophotometric methods and it was found that stress hormones do not significantly affect oxidation status of seedlings.

• Keywords: auksin; auksin-amidohidrolaza; jasmonska kiselina; apscizinska kiselina; salicilna kiselina
• Keywords (english): auxin; auxin amidohydrolase; jasmonic acid; abscisic acid; salicylic acid
• Language: croatian
• URN:NBN: urn:nbn:hr:217:852354
• 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: Access restricted to students and staff of home institution
• Created on: 2017-05-02 08:18:00