@article{
author = "Jovičić, Branko and Topisirović, Ljubiša and Kojić, Milan",
year = "2005",
abstract = "Soj P. putida WCS358 naseljava rizosferu biljaka i utiče pozitivno na rast nekih od njih (pokazano za krompir). Efekat pospešivanja rasta biljaka čiju rizosferu nastanjuje P. putida rezultat je njegovog inhibitornog dejstva na rast štetnih mikroorganizama. Usled uslova rasta u rizosferi koji podrazumevaju manjak nutrijenata i/ili velike gustine populacija ove bakterije su razvile mehanizme adaptacije koji su rezultat promene genske ekspresije regulisane sigma faktorom RpoS. Prethodno smo pokazali da rpoS gen, u stadonarnoj fazi, na transkripcionom nivou pozitivno reguliše PsrA regulator koji se specifično vezuje za palindromsku sekvencu C/GAAAC N2-4 GTTTG/C rpoS promotora. Takođe smo pokazali da se osim za promotor ipoS gena u uslovima stresa i u stacionarnoj fazi PsrA vezuje i za palindromske sekvence promotora različitih gena čime dovodi do promena u metabolizmu neophodnom za adaptaciju na novonastale uslove. Sam psrA gen negativno je autoregulisan. Analiza posttranskripcione regulacije ekspresije rpoS rezultovala je u otkrivanju dva domena uzvodnog netranslatirajućeg regiona rpoS koja učestvuju u translacionoj regulaciji istog. Na osnovu ovih rezultata predložili smo model regulacije u uslovima gladovanja po kojem PsrA transkripcioni regulator ima glavnu ulogu. Postojeća znanja o genskoj ekspresiji u stacionarnoj fazi kod roda Pseudomonas mogu u mnogome da pomognu u boljoj i kontrolisanijoj primeni ovih bakterija u poljoprivredi., The strain Pseudomonas putida WCS358 has been characterized as a potato growth promoting mizosphere colonizing bacteria. The plant-growth stimulatory effect of this strain is mainly caused by the suppression of the growth of deleterious microorganisms in the mizosphere. In mizosphere most of life bacteria are under nutrient starvation or in stationary phase. Adaptation to stress condition can take place via the changes in gene expression (of about 800 genes in Pseudomonas) by the stationary phase sigma factor called RpoS. In our previous work we determined a Pseudomonas regulator, PsrA, which enhances transcription of the rpoS sigma factor gene at stationary phase by specific binding to palindromic sequence C/GAAAC N2-4 GTTTG/C in its promoter. In our recent work we demonstrated that PsrA regulator recognized entering bacteria to stationary phase or stress and changed metabolism by specific interaction with the same palindromic sequences present in promoters of genes responsible to overtake the problems. Many genes in the PsrA regulon are related to starvation stress response. Expression studies with psrA transcriptional fusions revealed that psrA gene was negatively regulated by its own product and is under additional control in response to growth phase. Furthermore, our work also was focused to posttranscriptional regulation of rpoS gene expression. We identified two important domains on untranslated region of rpoS RNA involved in translational regulation. We propose model of regulation under starvation conditions where PsrA transcriptional regulator has central regulatory function. The present knowledge of regulation of gene expression under stationary phase in growth promoting Pseudomonas could be helpful for better control and exploitation of these bacteria in agriculture.",
publisher = "Savez poljoprivrednih inženjera i tehničara, Beograd",
journal = "Journal of Scientific Agricultural Research",
title = "Regulacija genske ekspresije pod uslovima stresa, nedostatka ugljenika i u stadonarnoj fazi kod Pseudomonas putida WCS358, Regulation of gene expression under stress, carbon starvation and stationary phase in rhizosphere-colonizing plant growth-promoting strain Pseudomonas putida WCS358",
pages = "185-171",
number = "5",
volume = "66",
url = "https://hdl.handle.net/21.15107/rcub_imagine_234"
}
