title: Arabidopsis RelA/SpoT homologs implicate (p)ppGpp in plant signaling.
abstract: Arabidopsis RPP5 is a member of a large class of pathogen resistance genes encoding nucleotide-binding sites and leucine-rich repeat domains. Yeast two-hybrid analysis showed that RPP5 specifically interacts with At-RSH1, an Arabidopsis RelA/SpoT homolog. In Escherichia coli, RelA and SpoT determine the level of guanosine tetraphosphate (ppGpp) and guanosine pentaphosphate (pppGpp), which are the effector nucleotides of the bacterial stringent response. Functional analysis in E. coli and in Streptomyces coelicolor A3 (2) showed that At-RSH1 confers phenotypes associated with (p)ppGpp synthesis. We characterized two additional Arabidopsis RelA/SpoT homologs, At-RSH2 and At-RSH3. At-RSH genes may regulate a rapid plant (p)ppGpp-mediated response to pathogens and other stresses.
authors.affiliation: The Sainsbury Laboratory, John Innes Centre, Norwich NR4 7UH, United Kingdom.
authors.forename: E A
authors.initials: EA
authors.lastname: van der Biezen
authors.forename: J
authors.initials: J
authors.lastname: Sun
authors.forename: M J
authors.initials: MJ
authors.lastname: Coleman
authors.forename: M J
authors.initials: MJ
authors.lastname: Bibb
authors.forename: J D
authors.initials: JD
authors.lastname: Jones
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins; D004926:Escherichia coli / Q000378:metabolism; D006158:Guanosine Pentaphosphate / Q000235:genetics / Q000378:metabolism*; D008025:Ligases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013302:Streptomyces / Q000378:metabolism; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; D010940:Plant Proteins; C406739:RSH1 protein, Arabidopsis; C406740:RSH2 protein, Arabidopsis; D006158:Guanosine Pentaphosphate; D008025:Ligases; C028812:guanosine 3',5'-polyphosphate synthetases