CNI1/ATL31, a RING-type ubiquitin ligase that functions in the carbon/nitrogen response for growth phase transition in Arabidopsis seedlings

Takeo Sato, Shugo Maekawa, Shigetaka Yasuda, Yutaka Sonoda, Etsuko Katoh, Takanari Ichikawa, Miki Nakazawa, Motoaki Seki, Kazuo Shinozaki, Minami Matsui, Derek B. Goto, Akira Ikeda, Junji Yamaguchi

Research output: Contribution to journalArticlepeer-review

105 Citations (Scopus)


Plants are able to sense and respond to changes in the balance between carbon (C) and nitrogen (N) metabolite availability, known as the C/N response. During the transition to photoautotrophic growth following germination, growth of seedlings is arrested if a high external C/N ratio is detected. To clarify the mechanisms for C/N sensing and signaling during this transition period, we screened a large collection of FOX transgenic plants, overexpressing full-length cDNAs, for individuals able to continue post-germinative growth under severe C/N stress. One line, cni1-D (carbon/nitrogen insensitive 1-dominant), was shown to have a suppressed sensitivity to C/N conditions at both the physiological and molecular level. The CNI1 cDNA encoded a predicted RING-type ubiquitin ligase previously annotated as ATL31. Overexpression of ATL31 was confirmed to be responsible for the cni1-D phenotype, and a knock-out of this gene resulted in hypersensitivity to C/N conditions during post-germinative growth. The ATL31 protein was confirmed to contain ubiquitin ligase activity using an in vitro assay system. Moreover, removal of this ubiquitin ligase activity from the overexpressed protein resulted in the loss of the mutant phenotype. Taken together, these data demonstrated that CNI1/ATL31 activity is required for the plant C/N response during seedling growth transition.

Original languageEnglish
Pages (from-to)852-864
Number of pages13
JournalPlant Journal
Issue number5
Publication statusPublished - Dec 2009
Externally publishedYes


  • C/N balance
  • FOX hunting system
  • Growth checkpoint
  • Nutrient response
  • Sugar response
  • Ubiquitin-26S proteasome system

Field of Science*

  • 1.6 Biological sciences

Publication Type*

  • 1.1. Scientific article indexed in Web of Science and/or Scopus database


Dive into the research topics of 'CNI1/ATL31, a RING-type ubiquitin ligase that functions in the carbon/nitrogen response for growth phase transition in Arabidopsis seedlings'. Together they form a unique fingerprint.

Cite this