Casein kinase II α subunits affect multiple developmental and stress-responsive pathways in Arabidopsis

Plant J. 2012 Jan;69(2):343-54. doi: 10.1111/j.1365-313X.2011.04794.x. Epub 2011 Oct 25.

Abstract

Casein kinase II (formerly known as CK2), a ubiquitous Ser/Thr kinase, plays critical roles in all higher organisms including plants. The CK2 holoenzyme consists of two catalytic α subunits and two regulatory β subunits. The Arabidopsis genome has four α subunit and four β subunit genes, and members of both the α and β subunit families have been shown to be localized in the cytoplasm, nucleus and also in chloroplasts. However, the biological roles of CK2 subunits have not been fully characterized yet. Here we identified T-DNA insertion mutants in three α subunit genes (α1, α2 and α3) and made double and triple mutants. The CK2 α1α2α3 triple mutants displayed reduced CK2 activity compared with wild-type seedlings. Phenotypic characterization showed that CK2 α1α2α3 triple mutants are late flowering under both long- and short-day conditions. Genes encoding floral integrators are differentially regulated in the triple mutant compared with the wild-type plants. CK2 α1α2α3 triple mutants also displayed reduced hypocotyl growth, smaller cotyledon size and a reduced number of lateral roots compared with wild-type seedlings under light. Abscisic acid-induced blockage of seed germination and cotyledon greening is reduced in CK2 α subunit mutants in an additive manner. Moreover, CK2 α subunit mutants are also hyposensitive to a NaCl-induced blockage of seed germination. Taken together, these data suggest that CK2 α subunits affect diverse developmental and stress responsive pathways in Arabidopsis.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Abscisic Acid / metabolism*
  • Arabidopsis / drug effects
  • Arabidopsis / enzymology*
  • Arabidopsis / genetics
  • Arabidopsis / physiology
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Casein Kinase II / genetics
  • Casein Kinase II / metabolism*
  • Cell Nucleus / metabolism
  • Flowers / enzymology
  • Flowers / genetics
  • Flowers / growth & development
  • Flowers / physiology
  • Germination / drug effects
  • Germination / physiology
  • Hypocotyl / drug effects
  • Hypocotyl / enzymology
  • Hypocotyl / genetics
  • Hypocotyl / physiology
  • Models, Biological
  • Mutagenesis, Insertional
  • Phosphorylation
  • Photoperiod
  • Plant Roots / drug effects
  • Plant Roots / enzymology
  • Plant Roots / genetics
  • Plant Roots / physiology
  • Recombinant Proteins
  • Seedlings / drug effects
  • Seedlings / enzymology
  • Seedlings / genetics
  • Seedlings / physiology
  • Seeds / drug effects
  • Seeds / enzymology
  • Seeds / genetics
  • Seeds / physiology
  • Sodium Chloride / pharmacology*
  • Stress, Physiological / drug effects
  • Stress, Physiological / physiology*
  • Time Factors

Substances

  • Arabidopsis Proteins
  • Recombinant Proteins
  • Sodium Chloride
  • Abscisic Acid
  • Casein Kinase II