Negative regulation of CCaMK is essential for symbiotic infection

Jinqiu Liao, Sylvia Singh, Md S. Hossain, Stig U. Andersen, Loretta Ross, Dario Bonetta, Yonghong Zhou, Shusei Sato, Satoshi Tabata, Jens Stougaard, Krzysztof Szczyglowski, Martin Parniske

Research output: Contribution to journalArticlepeer-review

37 Citations (Scopus)


One of the earliest responses of legumes to symbiotic signalling is oscillation of the calcium concentration in the nucleoplasm of root epidermal cells. Integration and decoding of the calcium-spiking signal involve a calcium- and calmodulin-dependent protein kinase (CCaMK) and its phosphorylation substrates, such as CYCLOPS. Here we describe the Lotus japonicus ccamk-14 mutant that originated from a har1-1 suppressor screen. The ccamk-14 mutation causes a serine to asparagine substitution at position 337 located within the calmodulin binding site, which we determined to be an in vitro phosphorylation site in CCaMK. We show that ccamk-14 exerts cell-specific effects on symbiosis. The mutant is characterized by an increased frequency of epidermal infections and significantly compromised cortical infections by Mesorhizobium loti and also the arbuscular mycorrhiza fungus Rhizophagus irregularis. The S337 residue is conserved across angiosperm CCaMKs, and testing discrete substitutions at this site showed that it participates in a negative regulation of CCaMK activity, which is required for the cell-type-specific integration of symbiotic signalling.

Original languageEnglish
Pages (from-to)572-584
Number of pages13
JournalPlant Journal
Issue number4
Publication statusPublished - 2012 Nov
Externally publishedYes


  • CCaMK
  • Lotus japonicus
  • legumes
  • phosphorylation
  • symbiosis

ASJC Scopus subject areas

  • Genetics
  • Plant Science
  • Cell Biology


Dive into the research topics of 'Negative regulation of CCaMK is essential for symbiotic infection'. Together they form a unique fingerprint.

Cite this