The role of imprinted gene ZmFIE1 during maize kernel development

Maize ( Zea mays L .) is a globally significant crop essential for food, feed, and bioenergy production. The maize kernel, serving as a primary sink for starch, proteins, lipids, and essential micronutrients, is crucial for enhancing maize yield and quality. Previous studies have established the critical role of Polycomb Repressive Complex 2 (PRC2) in regulating kernel development. In this study, we applied a reverse genetics approach to investigate the role of ZmFIE1 , the homolog of the PRC2 complex component Extra sex combs (Esc), in maize development. The functional loss of ZmFIE1 significantly reduces embryo size in the early stage but has a relatively small impact on mature kernels. Integrating transcriptional and metabolomic profiling suggests that ZmFIE1 is involved in regulating nutrient balance between the endosperm and embryo. In addition, we demonstrate that ZmFIE1 is maternally expressed, and that the maternal inheritance of the fie1 allele significantly affects the imprinting status of paternally imprinted genes. Overall, our results suggest that ZmFIE1 is a key gene involved in the modulation of embryo development via regulating genomic imprinting and nutrient balance between embryo and endosperm, which provides new insights into the regulation mechanism underlying kernel development.