Abstract
Background: The anther cuticle, which is primarily composed of lipid polymers, is crucial for pollen development and plays important roles in sexual reproduction in higher plants. However, the mechanism underlying the biosynthesis of lipid polymers in maize (Zea mays. L.) remains unclear. Results: Here, we report that the maize male-sterile mutant shrinking anther 1 (sa1), which is allelic to the classic mutant male sterile 33 (ms33), displays defective anther cuticle development and premature microspore degradation. We isolated MS33 via map-based cloning. MS33 encodes a putative glycerol-3-phosphate acyltransferase and is preferentially expressed in tapetal cells during anther development. Gas chromatography-mass spectrometry revealed a substantial reduction in wax and cutin in ms33 anthers compared to wild type. Accordingly, RNA-sequencing analysis showed that many genes involved in wax and cutin biosynthesis are differentially expressed in ms33 compared to wild type. Conclusions: Our findings suggest that MS33 may contribute to anther cuticle and microspore development by affecting lipid polyester biosynthesis in maize.