Male sterile 44 confers dominant male sterility in maize by disrupting lipid metabolism pathways

Dominant genic male sterility (DGMS) is a valuable trait for harnessing heterosis in hybrid breeding of industrial crops, yet its underlying molecular mechanisms remain poorly understood. Here, we characterized Ms2629 , a complete dominant male-sterility mutant isolated from an EMS-mutagenized maize library. Cytological analysis revealed that the mutant underwent normal meiosis but exhibited defective Ubisch bodies and nonviable pollen grains. Through positional cloning, Ms2629 was identified as Ms44 , which encodes a lipid transfer protein specifically and highly expressed during early anther development. The specific single amino acid mutation in MS44 did not alter its cytoplasmic localization pattern. Integrated transcriptomic and lipidomic analyses further demonstrated that this dominant mutation disrupts the expression patterns of numerous known genic male sterility-related genes and lipid metabolic pathways essential for pollen formation. Our findings further elucidate the molecular mechanism by which the dominant Ms44 mutation confers male sterility and provide a theoretical foundation for utilizing DGMS in hybrid breeding for maize and related industrial crops. • Map-based cloning reveals that the mutant Ms2629 is caused by a single amino acid change in the lipid transfer protein MS44. • Transcriptomic and lipidomic analyses demonstrate that the mutation disrupts lipid metabolism and pollen wall development. • This study offering insights for dominant genic male sterility utilization in industrial crops