AtSIG6, a plastid sigma factor from Arabidopsis, reveals functional impact of cpCK2 phosphorylation.

Plastids contain sigma factors, i.e. gene-regulatory proteins for promoter binding and transcription initiation.

Dual temporal role of plastid sigma factor 6 in Arabidopsis development.

Plants contain nuclear-coded sigma factors for initiation of chloroplast transcription. The in vivo function of individual members of the sigma gene family has become increasingly accessible by knockout and complementation strategies. Here we have investigated plastid gene expression in an Arabidopsis (Arabidopsis thaliana) mutant with a defective gene for sigma factor 6.