Saha Sudip, DasGupta Maitrayee
a Department of Biochemistry ; University of Calcutta ; Kolkata , India.
Plant Signal Behav. 2015;10(9):e1028703. doi: 10.1080/15592324.2015.1028703.
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.
最近我们报道，共生受体激酶（SYMRK）细胞内激酶结构域的过表达（SYMRK-kd）会过度激活蒺藜苜蓿中的自发结瘤，这表明SYMRK胞外结构域在限制根瘤数量方面的重要性。为了阐明SYMRK-kd是否克服了sunn和镰刀途径以过度激活根瘤器官发生，我们在这些突变体中过表达了SYMRK-kd，并分析了在没有根瘤菌的情况下的自发结瘤情况。skl/SYMRK-kd根中的自发结瘤比A17/SYMRK-kd根高2倍，这表明SYMRK-kd诱导的根瘤器官发生对乙烯敏感。有趣的是，sunn/SYMRK-kd根未能产生任何自发根瘤，这直接表明LRR-RLK SUNN在非共生条件下SYMRK-kd介导的根瘤发育中起作用。我们推测SUNN和SYMRK受体之间存在相互作用，以激活和限制根瘤发育。
