MicroRNA networks integrate development and metabolism to control spikelet fate: implications for cereal yield improvement

Grain cereal crops such as barley, wheat, and rice are vital staples in temperate regions, with spikeletformationbeingcrucialtotheirproductivity.Spikeletsurvivalisamajorfactorinyieldimprovementandis affected by both genetics and environmental stress. Despite breeding efforts, grain yieldimprovement has stagnated due to a limited understanding of the regulatory networks that governspikelet fertility. This review examines the role of microRNAs (miRNAs) in regulating spikeletdevelopment and abortion, with particular emphasis on miR156–SPL, and miR172–AP2. It discussesmorphological differences among barley, wheat, and rice and highlights specific miRNA-target genepairs that affect flowering time and spikelet fertility. The review also examines how environmentalfactors influence miRNA pathways and how miRNA misregulation affects anther and pollen growth.Overall, it emphasizes the potential of miRNA-transcription factor modules for developing targetedbreeding strategies to improve spikelet survival and increase yields in cereal crops.