A Rice Glutamyl-tRNA Synthetase Modulates Early Anther Cell Division and Patterning.

Aminoacyl-tRNA synthetases (aaRSs) have housekeeping roles in protein synthesis, but little is known about how these aaRSs are involved in organ development. Here, we report that a rice () glutamyl-tRNA synthetase (OsERS1) maintains proper somatic cell organization and limits the overproliferation of male germ cells during early anther development. The expression of is specifically detectable in meristematic layer 2-derived cells of the early anther, and anthers exhibit overproliferation and disorganization of layer 2-derived cells, producing fused lobes and extra germ cells in early anthers. The conserved biochemical function of OsERS1 in ligating glutamate to tRNA is enhanced by its cofactor aaRS OsARC. Furthermore, metabolomics profiling revealed that OsERS1 is an important node for multiple metabolic pathways, indicated by the accumulation of amino acids and tricarboxylic acid cycle components in anthers. Notably, the anther defects of the mutant are causally associated with the abnormal accumulation of hydrogen peroxide, which can reconstitute the phenotype when applied to wild-type anthers. Collectively, these findings demonstrate how aaRSs affect male organ development in plants, likely through protein synthesis, metabolic homeostasis, and redox status.