title: Cytokinin responses counterpoint auxin signaling during rhizobial infection.
abstract: The transcriptomics approach to study gene expression in root hairs from M. truncatula has shed light on the developmental events during rhizobial infection and the underlying hormone responses. This approach revealed the induction of several cyclins and an aurora kinase which suggests that the cell-division machinery plays a role in rhizobial infection. Changes in the cell cycle in plants are governed by hormones, in particular auxin and cytokinin. Through gene expression and genetic analyses, we have shown auxin plays a role during rhizobial infection. Here we provide further analysis of the data showing the induction of a set of cytokinin signaling components. These include genes encoding 2 cytokinin-activating enzymes, the cytokinin receptor CRE1, and 5 type-A cytokinin response regulators. We discuss the possible interactions between auxin and cytokinin signaling during the infection process. We also consider a potential role for cytokinin signaling in rhizobial attachment.
authors.affiliation: a Cell & Developmental Biology ; John Innes Center; Norwich Research Park ; Norwich , UK.
authors.forename: Cheng-Wu
authors.initials: CW
authors.lastname: Liu
authors.forename: Andrew
authors.initials: A
authors.lastname: Breakspear
authors.forename: Sonali
authors.initials: S
authors.lastname: Roy
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Murray
mesh_terms: D001422:Bacterial Adhesion; D003583:Cytokinins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D046913:Medicago truncatula / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology*; D009154:Mutation; D010641:Phenotype; D055170:Plant Root Nodulation; D018517:Plant Roots / Q000235:genetics / Q000382:microbiology; D012231:Rhizobium / Q000502:physiology*; D015398:Signal Transduction
chemical_list: D003583:Cytokinins; D007210:Indoleacetic Acids
keywords: Auxin; auxin response factor; auxin responses; cytokinin; cytokinin response regulator; cytokinin signaling; ethylene; hormonal interactions; infection thread; plant microbe interactions; rhizobia; rhizobial infection; symbiosis