Abstract
Arabidopsis trichomes are branched-hair-like protruding giant cells on the leaf surface and each of them has a large nucleus caused by endoreduplication. Developing trichomes are known to express cyclin-dependent kinase CDKA (CDC2a). We expressed a fusion protein, CDKA-GFP, under the control of the CDKA promoter in Arabidopsis, and observed its expression period and intracellular localization. CDKA-GFP was expressed at early stages of trichome development and localized mainly in the nucleus, allowing us to expect that a certain cyclin is involved in the CDKA complex during trichome development.
To confirm this postulate, we expressed CDKA-GFP in Arabidopsis under the control of a developing-trichome-specific promoter (the CDKA promoter region of -591 to +4 bp from transcription initiation point) and CDKA-interacting proteins were co-immunoprecipitated with anti-GFP antibody. We will report the expected cyclin detected as a coprecipitated protein and discuss the function of the CDKA/Cyclin complex during endoreduplication in trichomes.
