title: New horizons for (p)ppGpp in bacterial and plant physiology.
abstract: A hyperphosphorylated guanosine nucleotide, (p)ppGpp, was initially identified as the effector molecule responsible for the stringent response in Escherichia coli. However, a rapidly growing number of reports proves that (p)ppGpp-mediated regulation is conserved in many bacteria and even in plants. It is now clear that (p)ppGpp acts as a global regulator during physiological adaptation of the organism to a plethora of environmental conditions. Adaptation is not only essential for surviving periods of stress and nutrient exhaustion but also for the interaction of bacteria with their eukaryotic host, as observed during pathogenesis and symbiosis, and for bacterial multicellular behaviour. Recently, there have been several new discoveries about the effects of (p)ppGpp levels, balanced by RelA-SpoT homologue proteins, in diverse organisms.
authors.affiliation: Centre of Microbial and Plant Genetics, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium.
authors.forename: Kristien
authors.initials: K
authors.lastname: Braeken
authors.forename: Martine
authors.initials: M
authors.lastname: Moris
authors.forename: Ruth
authors.initials: R
authors.lastname: Daniels
authors.forename: Jos
authors.initials: J
authors.lastname: Vanderleyden
authors.forename: Jan
authors.initials: J
authors.lastname: Michiels
mesh_terms: D017360:Arabidopsis / Q000502:physiology; D018407:Bacterial Physiological Phenomena; D004926:Escherichia coli / Q000502:physiology; D006158:Guanosine Pentaphosphate / Q000502:physiology*; D008025:Ligases / Q000502:physiology; D018521:Plant Physiological Phenomena
chemical_list: D006158:Guanosine Pentaphosphate; D008025:Ligases; C028812:guanosine 3',5'-polyphosphate synthetases