A non-redundant role of OsGELP87 in lipid-associated pollen development and fertility in rice

Abstract Pollen fertility in flowering plants relies on precise lipid metabolism, yet the enzymatic regulators underlying these processes remain incompletely understood. Here we identify OsGELP87 , a GDSL-type esterase/lipase, as a key regulator of male gametophyte development in rice ( Oryza sativa ). Phylogenetic analysis revealed that OsGELP87 lacks closely related paralogs, suggesting limited functional redundancy. CRISPR–Cas9 genome editing revealed impaired pollen wall architecture, abnormal nuclear morphology, and reduced lipid droplet accumulation, causing reduced male fertility. Complete loss-of-function mutants were not recovered. Transcriptome and qRT–PCR analyses revealed disrupted lipid metabolic networks, including suppression of FAD2 and pollen lipid transfer proteins, together with altered redox regulators. Structural modelling showed that a premature stop codon in exon 3 abolishes conserved C-terminal motifs and predicted palmitoylation sites, likely impairing catalytic function. Functional analyses suggest that OsGELP87 participates in sporopollenin/tryphine assembly during pollen wall formation and triacylglycerol mobilization during pollen germination. Population genomic analysis uncovered five haplotypes with distinct geographic distributions and fertility phenotypes, while no haplotypes carrying non-functional alleles were detected. Together, these results identify OsGELP87 as a non-redundant regulator of lipid-associated cellular processes required for pollen development and provide new insight into how lipid metabolism contributes to reproductive cell differentiation in plants.