Quantitative and cell type-specific transcriptional regulation of A-type cyclin-dependent kinase in Arabidopsis thaliana

Dev Biol. 2009 May 15;329(2):306-14. doi: 10.1016/j.ydbio.2009.03.002. Epub 2009 Mar 11.

Abstract

A-type cyclin-dependent kinase (CDKA) is an ortholog of yeast Cdc2/Cdc28p, and is assumed to have an essential function in plant growth and organogenesis. Previous studies revealed that its kinase activity is controlled by post-translational modifications, such as binding to cyclins and phosphorylations, but its transcriptional regulation is poorly understood. Here, we generated a promoter dissection series of Arabidopsis (Arabidopsis thaliana) CDKA;1, and used beta-glucuronidase (GUS) gene-fused reporter constructs for expression analyses in planta. The results revealed two types of transcriptional control in shoots: general quantitative regulation and cell type-specific regulation. We identified a promoter region that promotes CDKA;1 expression in the leaf epidermis, but not in the L1 layer of the shoot apical meristem. This region also directed abaxial side-biased expression, which may be linked to the adaxial/abaxial side specification. Another reporter construct showed that CDKA;1 expression in the inner layers of leaves is controlled by a distinct regulatory region in the promoter. These results suggest that the transcriptional regulation of CDKA;1 may play a key role in proper development of leaves by coordinating cell division and differentiation of different cell types.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / enzymology*
  • Arabidopsis / genetics
  • Cyclin-Dependent Kinases / genetics*
  • Gene Expression Regulation, Enzymologic*
  • Gene Expression Regulation, Plant*
  • Glucuronidase / genetics
  • Plant Leaves / enzymology
  • Promoter Regions, Genetic
  • Transcription, Genetic*

Substances

  • Cyclin-Dependent Kinases
  • Glucuronidase