Starch is a vital energy source in cereal crops like rice. A new study focused on a rice mutant called flo16 with abnormal starch grain formation. The mutant had changes in amylose content and structure. The gene FLO16 was identified as encoding a protein involved in redox balance, crucial for starch synthesis in rice seeds. Mutant plants had lower ATP levels and reduced enzyme activity for starch production. Overexpressing FLO16 led to heavier grains, suggesting a potential use in rice breeding to improve yield. This research sheds light on how starch is made in rice seeds and how it affects seed development.