Identification and characterization of transcription factor ZmEREB94 involved in starch synthesis in maize.

Maize is an important food crop and industrial material owing to its high starch content. However, the mechanism of starch synthesis is not fully elucidated, especially with regard to the expression and regulation of starch synthetic genes. The APETALA2/Ethylene Responsive Factor (AP2/ERF) family plays a crucial role in various biological processes via regulating gene expression. In this study, the ZmEREB94 gene was identified through co-expression analysis. Bioinformatics analysis confirmed that ZmEREB94 belongs to the AP2/ERF family. Expression pattern analysis showed that this protein is strongly expressed in the maize endosperm. A ZmEREB94-GFP fusion protein was localized in the nuclei of onion epidermal cells, and ZmEREB94 showed strong transcriptional activation activity, which indicated that this protein is a transcription factor. In addition, yeast-one hybrid assays and transient expression in maize endosperm showed that ZmEREB94 could directly bind to the ZmSSI promoter and indirectly regulate ZmSh2 and ZmGBSSI expression. Our results revealed that ZmEREB94 might act as a key regulator of starch synthesis in maize.