title: Does SUNN-SYMRK Crosstalk occur in Medicago truncatula for regulating nodule organogenesis?
abstract: Recently we reported that overexpression of intracellular kinase domain of Symbiosis Receptor Kinase (SYMRK-kd) hyperactivated spontaneous nodulation in Medicago truncatula indicating the importance of SYMRK ectodomain in restricting nodule number. To clarify whether sunn and sickle pathways were overcome by SYMRK-kd for hyperactivation of nodule organogenesis, we overexpressed SYMRK-kd in these mutants and analyzed for spontaneous nodulation in absence of rhizobia. Spontaneous nodulation in skl/SYMRK-kd roots was 2-fold higher than A17/SYMRK-kd roots indicating nodule organogenesis induced by SYMRK-kd to be ethylene sensitive. Intriguingly, sunn/SYMRK-kd roots failed to generate any spontaneous nodule which directly indicate the LRR-RLK SUNN to have a role in SYMRK-kd mediated nodule development under non-symbiotic conditions. We hypothesize a crosstalk between SUNN and SYMRK receptors for activation as well as restriction of nodule development.
authors.affiliation: a Department of Biochemistry ; University of Calcutta ; Kolkata , India.
authors.forename: Sudip
authors.initials: S
authors.lastname: Saha
authors.affiliation: a Department of Biochemistry ; University of Calcutta ; Kolkata , India.
authors.forename: Maitrayee
authors.initials: M
authors.lastname: DasGupta
mesh_terms: D046913:Medicago truncatula / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D038081:Organogenesis; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D055170:Plant Root Nodulation; D017434:Protein Structure, Tertiary; D053204:Root Nodules, Plant / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D010940:Plant Proteins
keywords: SUNN; SYMRK; autoregulation of nodulation; ethylene; sickle; spontaneous nodulation; supernodulation