Journal Article Research Support, Non-U.S. Gov't gene expression DNA-Directed RNA Polymerases EC 2.7.7.6 Plant Proteins Review Biogenic signals Chloroplast Proteins Chloroplast biogenesis PEP-associated proteins Protein Isoforms Protein Subunits RNA, Plant Zea mays (maize) ZmpTAC12 cellular communication chloroplast biogenesis developmental regulation light regulation nucleo–plastid interaction photomorphogenesis plants plastid RNA polymerases. plastid-encoded plastid RNA polymerase (PEP)-polymerase plastids ssDN/RNA-binding