title: Stress response in Pectobacterium atrosepticum SCRI1043 under starvation conditions: adaptive reactions at a low population density.
abstract: The adaptive reactions of plant pathogenic bacterium Pectobacterium atrosepticum SCRI1043 under starvation conditions were studied. The main emphasis was given to the peculiarities of stress responses depending on the bacterial population densities. When bacteria were subjected to starvation at high population densities (10(7)-10(9) CFU ml(-1)), their adaptive reactions conformed to the conventional conception of bacterial adaptation related to autolysis of part of the population, specific modification of cell ultrastructure, activation of expression of stress responsive genes and acquiring cross protection against other stress factors. In contrast, at low initial population densities (10(3)-10(5) CFU ml(-1)), as described in our recent work, the cell density increased due to multiple cell division despite the absence of exogenous growth substrate. Here we present data that demonstrate that such unconventional behavior is part of a stress response, which provides increased stress tolerance while retaining virulence. Cell morphology and gene expression in high- and low-cell-density starving Pba cultures were compared. Our investigation demonstrates the existence of alternative adaptive strategies enabling pathogenic bacteria to cope with a variety of stress factors, including starvation, especially necessary when residing outside of their host.
authors.affiliation: Kazan Institute of Biochemistry and Biophysics, Kazan Scientific Center, Russian Academy of Sciences, Kazan, Russia. Electronic address: poe60@mail.ru.
authors.forename: Olga
authors.initials: O
authors.lastname: Petrova
authors.affiliation: Kazan Institute of Biochemistry and Biophysics, Kazan Scientific Center, Russian Academy of Sciences, Kazan, Russia; Department of Botany, Kazan Federal University, Kazan, Russia. Electronic address: gvy84@mail.ru.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Gorshkov
authors.affiliation: Kazan Institute of Biochemistry and Biophysics, Kazan Scientific Center, Russian Academy of Sciences, Kazan, Russia. Electronic address: aminochka_88@mail.ru.
authors.forename: Amina
authors.initials: A
authors.lastname: Daminova
authors.affiliation: Kazan Institute of Biochemistry and Biophysics, Kazan Scientific Center, Russian Academy of Sciences, Kazan, Russia. Electronic address: mageeva58@mail.ru.
authors.forename: Marina
authors.initials: M
authors.lastname: Ageeva
authors.affiliation: Department of Microbiology and Plant Pathology, University of Pretoria, South Africa. Electronic address: lucy.moleleki@up.ac.za.
authors.forename: Lucy N
authors.initials: LN
authors.lastname: Moleleki
authors.affiliation: Kazan Institute of Biochemistry and Biophysics, Kazan Scientific Center, Russian Academy of Sciences, Kazan, Russia. Electronic address: gogolev.yuri@gmail.com.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Gogolev
mesh_terms: D002455:Cell Division; D015870:Gene Expression; D046529:Microscopy, Electron, Transmission; D044043:Pectobacterium / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D011156:Population Density; D013312:Stress, Physiological
keywords: Bacterial ultrastructure; Cell division; Cross-protection; RpoS; Stringent response; ppGpp