Nodulation Receptor Kinase(NORK) functions as a co-receptor of Nod factor receptors to mediate rhizobial symbiosis in legumes, but its direct phosphorylation substrates that positively mediate root nodulation remain t...Nodulation Receptor Kinase(NORK) functions as a co-receptor of Nod factor receptors to mediate rhizobial symbiosis in legumes, but its direct phosphorylation substrates that positively mediate root nodulation remain to be fully identified.Here, we identified a GmNORK-Interacting Small Protein(GmNISP1) that functions as a phosphorylation target of GmNORK to promote soybean nodulation. GmNORKα directly interacted with and phosphorylated GmNISP1. Transcription of GmNISP1 was strongly induced after rhizobial infection in soybean roots and nodules. GmNISP1 encodes a peptide containing 90 amino acids with a “DY” consensus motif at its N-terminus.GmNISP1 protein was detected to be present in the apoplastic space. Phosphorylation of GmNISP1 by GmNORKα could enhance its secretion into the apoplast. Pretreatment with either purified GmNISP1 or phosphorylation-mimic GmNISP1~(12D) on the roots could significantly increase nodule numbers compared with the treatment with phosphorylation-inactive GmNISP1~(12A).The data suggested a model that soybean GmNORK phosphorylates GmNISP1 to promote its secretion into the apoplast, which might function as a potential peptide hormone to promote root nodulation.展开更多
基金supported by the National Natural Science Foundation of China (32090063 to Y.C.)the National Key R&D Program of China (2016YFD0100702 to Y.C.)+1 种基金the Natural Science Foundation of Hubei Province (2020CFA008 to Y.C.)a Fundamental Research Fund for the Central Universities (2662022SKYJ002 to Y.C.)。
文摘Nodulation Receptor Kinase(NORK) functions as a co-receptor of Nod factor receptors to mediate rhizobial symbiosis in legumes, but its direct phosphorylation substrates that positively mediate root nodulation remain to be fully identified.Here, we identified a GmNORK-Interacting Small Protein(GmNISP1) that functions as a phosphorylation target of GmNORK to promote soybean nodulation. GmNORKα directly interacted with and phosphorylated GmNISP1. Transcription of GmNISP1 was strongly induced after rhizobial infection in soybean roots and nodules. GmNISP1 encodes a peptide containing 90 amino acids with a “DY” consensus motif at its N-terminus.GmNISP1 protein was detected to be present in the apoplastic space. Phosphorylation of GmNISP1 by GmNORKα could enhance its secretion into the apoplast. Pretreatment with either purified GmNISP1 or phosphorylation-mimic GmNISP1~(12D) on the roots could significantly increase nodule numbers compared with the treatment with phosphorylation-inactive GmNISP1~(12A).The data suggested a model that soybean GmNORK phosphorylates GmNISP1 to promote its secretion into the apoplast, which might function as a potential peptide hormone to promote root nodulation.
