Epigenetic control of seed development and dormancy in cereals

Seeds, which are imperative for the propagation of seed plants, are also of major nutritional and economic value in agriculture. The precise dormancy and germination of crop seeds are important traits for modern agriculture. Pre-harvest sprouting (PHS) or the germination of seeds while attached to the plant before harvest, is a significant problem in crops, particularly in cereals. Therefore, understanding the various mechanisms of seed development and dormancy are imperative. While the molecular and hormonal aspects of seed dormancy are well understood, the role of epigenetic pathways is just beginning to unravel, particularly for cereal crops. The majority of this information has been generated in Arabidopsis; however, there is increasing focus on cereal crops such as rice and maize. Other important cereal crops, such as wheat and barley, lag behind even though seed dormancy and PHS are even more critical for these crops. Similarly, while much progress has been made in understanding the role of histone modifications in seed development, the role of DNA methylation has not been well investigated. In this article, we review the progress made in uncovering the role of epigenetic modifications in cereal crops with reference to knowledge generated in Arabidopsis.