This study uses single-cell transcriptomics to analyze the development of maize endosperm, a critical component of cereal grains. By analyzing 17,022 single cells, the researchers identified 12 cell clusters corresponding to five endosperm cell types, revealing complex transcriptional heterogeneity. They also delineated the temporal gene-expression patterns from 6 to 7 days after pollination and profiled the genomic DNA-binding sites of 161 transcription factors. A gene regulatory network was constructed by combining single-cell transcriptomic data with direct DNA-binding profiles, identifying 181 regulons containing genes encoding transcription factors and their high-confidence targets. The study provides a comprehensive framework for understanding cereal endosperm development and function at single-cell resolution, highlighting the heterogeneity within endosperm cell types and the complex regulatory mechanisms governing their differentiation. Additionally, the researchers validated three predicted key regulators experimentally, contributing to the improvement of grain yield and quality in cereal crops.This study uses single-cell transcriptomics to analyze the development of maize endosperm, a critical component of cereal grains. By analyzing 17,022 single cells, the researchers identified 12 cell clusters corresponding to five endosperm cell types, revealing complex transcriptional heterogeneity. They also delineated the temporal gene-expression patterns from 6 to 7 days after pollination and profiled the genomic DNA-binding sites of 161 transcription factors. A gene regulatory network was constructed by combining single-cell transcriptomic data with direct DNA-binding profiles, identifying 181 regulons containing genes encoding transcription factors and their high-confidence targets. The study provides a comprehensive framework for understanding cereal endosperm development and function at single-cell resolution, highlighting the heterogeneity within endosperm cell types and the complex regulatory mechanisms governing their differentiation. Additionally, the researchers validated three predicted key regulators experimentally, contributing to the improvement of grain yield and quality in cereal crops.