Effects of alfalfa nod gene-inducing flavonoids on nodABC transcription in Rhizobium meliloti strains containing different nodD genes.
Transcription of the nodulation genes nodABC in Rhizobium meliloti requires a plant flavonoid signal and nodD, a family of bacterial regulatory genes (nodD1, nodD2, and nodD3). Results from this study show that all previously identified nod gene inducers released by alfalfa seeds and roots induced nodABC-lacZ transcription in R. meliloti containing extra copies of nodD1, but only 4,4'-dihydroxy-2'-methoxychalcone gave high levels of induction with extra copies of nodD2. While mixtures of the methoxychalcone and luteolin showed a positive synergism with extra NodD1 protein, they apparently competed for binding to the NodD2 protein.
Hartwig
U A
UA
Department of Agronomy and Range Science, University of California, Davis 95616.
Maxwell
C A
CA
Joseph
C M
CM
Phillips
D A
DA
D000217:Acyltransferases; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D005419:Flavonoids / Q000378:metabolism* / Q000494:pharmacology; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005809:Genes, Regulator; D005838:Genotype; D047311:Luteolin; D000455:Medicago sativa / Q000502:physiology*; D017351:N-Acetylglucosaminyltransferases; D012231:Rhizobium / Q000235:genetics*; D014158:Transcription, Genetic / Q000187:drug effects
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D005419:Flavonoids; D000217:Acyltransferases; C060770:NodA protein, Rhizobiales; D017351:N-Acetylglucosaminyltransferases; C060771:NodC protein, Rhizobiales; D047311:Luteolin