Abstrakt

Different Types of Nitrogen Stress Response in Plant Pathogenic Bacterium Pectobacterium Atrosepticum

Olga Petrova, Vladimir Gorshkov, Iuliia Sergeeva, Sergey Tatarkin and Yuri Gogolev

Bacterial stress response under adverse conditions was long considered to be associated with the decrease of the population density because of the death of significant portion of the cells. However, recently in our studies by the example of carbon starvation of plant pathogenic Pectobacterium atrosepticum SCRI1043 it has been demonstrated that in the cases when the bacterial population density is low (below quorum level) the adaptation strategy may be related to cell proliferation and increase of cell number. Such kind of strategy enables low amount of cells to form functional population and implement intercellular communication necessary to resist stress factors. In the present study we show that the optimization of the population density and cell proliferation under stress conditions occurs not only during carbon starvation, but also in the course of nitrogen deficiency. Depending on initial population density, nitrogen stress response is realized according to alternative scenarios (related to either increase or decrease of cell titre) that have both common and distinctive features between themselves and the resembling reactions induced by carbon starvation.