The effect of biotic and abiotic stress on the content of flavonoid kaempferol in Arabidopsis thaliana

Abstract

Cilj ovog diplomskog rada bio je istražiti učinak biotičkog i abiotičkog stresa na sadržaj flavonoida kempferola u različitim tkivima vrste Arabidopsis thaliana. Učinak biotičkog stresa proučavan je na listovima spomenute vrste prilikom čega su korištena dva različita patogena: virus mozaika krastavca s pridruženom satelitnom RNA (CMVsat) te protist Plasmodiophora brassicae; učinak abiotičkog stresa (UV-B zračenja) proučavan je na kalusima iste vrste. Rezultati su pokazali da je uloga kempferola u obrambenom sustavu biljaka tijekom djelovanja biotičkog stresa specifična s obzirom na patogen (CMVsat uzrokuje smanjenje sadržaja kempferola kod inficiranih biljaka, a protist povećanje) te da ovaj flavonoid sudjeluje u prilagodbi biljke na štetno UV-B zračenje. Nadalje, proučavana je interakcija kompleksa kempferola, te njemu strukturno srodnog fisetina, i Eu3+ s dvolančanim (ds) i jednolančanim (ss) molekulama RNA izoliranim iz CMVsat-inficiranih biljaka. Rezultati dobiveni in vitro ukazali su kako bi se kompleks s Eu3+ mogao koristiti za dokazivanje prisutnosti dsRNA u biljnim tkivima.The aim of this graduation thesis was to investigate the influence of biotic and abiotic stress on the content of flavonoid kaempferol in different tissues of Arabidopsis thaliana. The influence of biotic stress was investigated on the Arabidopsis´s leafs; two pathogens were used: RNA satellite associated-cucumber mosaic virus (CMVsat) and protist Plasmodiophora brassicae; while the influence of abiotic stress (UV-B radiation) was investigated on Arabidopsis´s calluses. The results showed that kaempferol has a specific role in plant defense system during biotic stress (CMVsat reduces content of kaempferol in infected plants, while protist enhance it), and that this flavonoid is involved in plant adaptation to UV-B radiation. Furthermore, interactions between flavonoids kaempferol, or structurally related fisetin, and Eu3+ with double-stranded (ds) and single-stranded (ss) RNA isolated from CMVsat-infected species were studied. The in vitro obtained results showed that complex with Eu3+could be used for detection of dsRNAs in plant tissues