Novel role of ZmaNAC36 in co-expression of starch synthetic genes in maize endosperm.

Starch is an essential commodity that is widely used as food, feed, fuel and in industry. However, its mechanism of synthesis is not fully understood, especially in terms of the expression and regulation of the starch synthetic genes. It was reported that the starch synthetic genes were co-expressed during maize endosperm development; however, the mechanism of the co-expression was not reported. In this paper, the ZmaNAC36 gene was amplified by homology-based cloning, and its expression vector was constructed for transient expression. The nuclear localization, transcriptional activation and target sites of the ZmaNAC36 protein were identified. The expression profile of ZmaNAC36 showed that it was strongly expressed in the maize endosperm and was co-expressed with most of the starch synthetic genes. Moreover, the expressions of many starch synthesis genes in the endosperm were upregulated when ZmaNAC36 was transiently overexpressed. All our results indicated that NAC36 might be a transcription factor and play a potential role in the co-expression of starch synthetic genes in the maize endosperm.