Figure 1.

Overexpression of sense or antisense cak1At reduces CDK activity in the root meristem. Representative results of transgenic sense line S8 (sense) and antisense line A31 (antisense) together with the luciferase line 211 (Luc211) and wild-type plants (WT). Seedlings were treated with 1 μM DEX for cak1At transgenic lines and with 10 μM DEX for Luc211 for indicated hours. Fifteen micrograms of proteins extracted from roots was immunoblotted with (A) anti-Cak1At antibody and (B) anti-p34^cdc2aAt antibody. (C) Thirty-five micrograms of proteins was immunoprecipitated with anti-p34^cdc2aAt antibody, and immunoprecipitates were assayed for histone H1 kinase activity. (D) Fifteen micrograms of proteins extracted from roots that were grown in the absence (−) or presence (+) of 1 μM DEX for 3 days was immunoblotted with anti-p34^cdc2aAt antibody. Ten micrograms of proteins extracted from DEX-treated sense plants was reacted with (+) or without (−) lambda protein phosphatase (λPPase) and immunoblotted with anti-p34^cdc2aAt antibody.