biostudies-literatureMeng YNational Natural Science Foundation of China (National Science Foundation of China)511https://www.ebi.ac.uk/biostudies/studies/S-EPMC12804904biostudies-literatureUnknown17(1)Key cereal crops, including wheat, rice and maize, supply nearly 50% of the world's caloric intake, with starch constituting over 70% of the grain weight. However, the regulatory mechanisms underlying starch synthesis are poorly understood. In this study, we identify a transcription factor TaPIL1-5D, which binds to the promoters of ADP-glucose pyrophosphorylase small subunit 1 (TaAGPS1a-7A), granule-bound starch synthase I (TaGBSSI-4A), and branching enzyme II b (TaBEIIb-2D). Similarly, its homologous OsPIL11 and ZmPIL1 also activate the expression of the AGPS1, BEIIb, and GBSSI, and positively regulates grain starch synthesis. TaPIL1-5D and ZmPIL1 improve grain yields in two successive years. Nine alleles of TaPIL1-5B form three distinct haplotypes (Hap1-3), while TaPIL1-5B-Hap1 is represNature communicationsThe bHLH transcription factor PIL1 orchestrates starch synthesis in key cereal crops.PMC128049043220169832171924Li GLi XWang PKang GDu CCui JGuo TMeng YZeng WGe QfalseThe bHLH transcription factor PIL1 orchestrates starch synthesis in key cereal crops.Key cereal crops, including wheat, rice and maize, supply nearly 50% of the world's caloric intake, with starch constituting over 70% of the grain weight. However, the regulatory mechanisms underlying starch synthesis are poorly understood. In this study, we identify a transcription factor TaPIL1-5D, which binds to the promoters of ADP-glucose pyrophosphorylase small subunit 1 (TaAGPS1a-7A), granule-bound starch synthase I (TaGBSSI-4A), and branching enzyme II b (TaBEIIb-2D). Similarly, its homologous OsPIL11 and ZmPIL1 also activate the expression of the AGPS1, BEIIb, and GBSSI, and positively regulates grain starch synthesis. TaPIL1-5D and ZmPIL1 improve grain yields in two successive years. Nine alleles of TaPIL1-5B form three distinct haplotypes (Hap1-3), while TaPIL1-5B-Hap1 is repres2025-01-01T00:00:00Z2025 Dec2026-06-11T05:28:38.311Z2026-06-11T03:08:19.429ZS-EPMC128049044137221110.1038/s41467-025-67200-x