Lipidna peroksidacija i redoks status askorbata tijekom stresom-inducirane somatske embriogeneze bundeve

master's thesis

• Title (english): Lipid peroxidation and ascorbate redox state in stress-induced somatic embryogenesis of pumpkin
• Author: Sandi Paulišić
• Mentor: Snježana Mihaljević (mentor)
• Mentor: Dunja Leljak-Levanić (mentor)
• Committee member: Dunja Leljak-Levanić (predsjednik povjerenstva)
• Committee member: Snježana Mihaljević (član povjerenstva)
• Committee member: Sandra Radić Brkanac (član povjerenstva)
• Committee member: Nataša Bauer (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2012-12-17, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Somatska embriogeneza specifičan je oblik stresom-induciranog morfološkog odgovora u biljaka, a u bundeve (Cucurbita pepo L.) moguće ju je potaknuti na podlozi s dodatkom 2,4-D, ali i na podlozi bez hormona s dodatkom 1 mmol/L NH4+ kao jedinim izvorom dušika. Dok se o učincima 2,4-D na somatsku embriogenezu u biljaka zna dosta, fiziološki i morfogeni učinci asimilacije NH4+ na regulaciju somatske embriogeneze tek se istražuju. Analizirana je aktivnost askorbat peroksidaze, redoks status askorbata i lipidna peroksidacija u embriogenom tkivu bundeve. Utvrđeno je da je specifična aktivnost APX u obrnutoj korelaciji s veličinom i mitotskim indeksom embriogenih stanica raslih na podlozi s NH4+, dok je sadržaj L-AA bio manji u tkivu raslom na podlozi s NH4+ nego s 2,4-D. Povećan udio DHA izmjeren je nakon presađivanja tkiva s MS podloga koje sadrže NH4+ ili 2,4D na podlogu MS s nepromijenjenim izvorima dušika i bez hormona, koja pospješuje rast embriogenog tkiva i razvitak starijih stadija embrija. Nije izmjerena značajnija razina lipidne peroksidacije u embriogenom tkivu, neovisno o tretmanu.

Abstract (english)

Somatic embryogenesis represents specific form of stress-induced morphogenic response in plants, and in pumpkin (Cucurbita pepo L.) it can be induced on medium with 4,5 μmol/L 2,4-D and on medium without hormones but with 1 mmol/L NH4+ as the sole source of nitrogen. The effects of 2,4-D on somatic embryogenesis are well known, but physiological and morphogenic aspects of NH4+ assimilation on regulation of somatic embryogenesis are still being investigated. Ascorbate peroxidase activity, redox state of ascorbate and lipid peroxidation were analyzed in pumpkin embryogenic tissue. Results confirmed inverse correlation between specific APX activity and cell size and elongation of embryogenic cells grown on medium with NH4+, while L-AA content was lower in tissue grown on NH4+ then on 2,4-D. The increased L-AA content was measured after transplantation of tissue from MS medium containing NH4+ or 2,4-D to MS medium with unaltered nitrogen sources and without hormones. Lipid peroxidation measured in embryogenic tissue was not significant, regardless of tretment.

• Keywords: amonijevi ioni; askorbat; askorbat peroksidaza; bundeva; lipidna peroksidacija; somatska embriogeneza
• Keywords (english): ammonium ions; ascorbate; ascorbate peroxidase; lipid peroxidation; pumpkin; somatic embryogenesis
• Language: croatian
• URN:NBN: urn:nbn:hr:217:660714
• 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 10:20:46