Impact of abiotic stress on germination and growth of transgenic Arabidopsis thaliana seedlings with increased expression of BPM1 i SerRS genes

U prethodnim istraživanjima pripremljene su transgenične linije modelne biljke Arabidopsis thaliana transformirane genima BPM1 (AT5G19000.1) i SerRS (AT5G27470) koji sudjeluju u homeostazi proteina. Protein BPM1 je adaptor ubikvitin ligaze kulin 3 te sudjeluje u procesu obilježavanja proteina koji se razgrađuju putem proteasoma 26S. Protein SerRS je seril-tRNA sintetaza koja sudjeluje u procesu sinteze proteina. Dosadašnja istraživanja ekspresije gena BPM1 i SerRS upućuju na ulogu oba ova proteina tijekom stresa. U ovom radu je funkcionalno okarakterizirana uloga proteina BPM1 i SerRS tijekom solnog i osmotskog stresa, i prilikom izlaganja apscizinskoj kiselini. Istražena je klijavost biljaka te je praćen rast korijena na hranidbenim podlogama uz dodatak 0,1-50 μM apscizinske kiseline, 50-200 mM NaCl, 25-150 mM KCl i 100-500 mM manitola. Pokazano je da pojačana ekspresija proteina BPM1 omogućava bolje klijanje sjemenki transgeničnih biljaka izloženih stresu, u odnosu na biljke divljeg tipa dok pojačana ekspresija proteina SerRS smanjuje klijanje transgeničnih sjemenki. Rast korijena transgeničnih linija prilikom izloženosti stresu nije značajnije varirao u odnosu na biljke divljeg tipa.In previous researches the transgenic lines of the model plant Arabidopsis thaliana had been prepared and transformed with genes BPM1 (AT5G19000.1) and SerRS (AT5G27470) which are part of homeostasis of proteins. The BPM1 protein is adapter for ubiquitin ligase cullin 3 and it participates in the process of marking the proteins for degradation by proteasome 26S. The SerRS protein is seryl-tRNA synthetase which participates in process of protein synthesis. Recent research of BPM1 and SerRS genes expression indicates that these two genes have function during stress. In this thesis the function of BPM1 and SerRS proteins are characterized during salt and osmotic stress, and during exposure to the abscisic acid. Germination of plants has been analyzed and root growth was monitored on nutrient media with addition of 0.1-50 μM abscisic acid, 50-200 mM sodium chloride, 25-150 potassium chloride and 100-500 mM mannitol. It was shown that enhanced expression of BPM1 protein allows increased germination of seeds exposed to stress with regard to wild type plants. Enhanced expression of SerRS protein decreases germination of transgenic seeds. Root growth of transgenic lines did not significantly vary in comparison to wild type plants during stress exposure