The Golgi-localized transporter OsPML3 is involved in manganese homeostasis and complex N-glycan synthesis in rice.

This article focuses on the characterization of OsPML3, a manganese (Mn) transporter in rice (Oryza sativa) belonging to the UNCHARACTERIZED PROTEIN FAMILY 0016 (UPF0016), and its role in Mn homeostasis and Golgi apparatus functions. OsPML3 is localized in the Golgi apparatus and is highly expressed in rapidly developing tissues, where it facilitates Mn transport essential for cell wall polysaccharide deposition and late-stage Golgi N-glycosylation, particularly the biosynthesis of the Lewis A structure. Knockout of OsPML3 leads to reduced Mn content in young leaves, impaired growth under Mn-deficient conditions, altered cell wall composition, defective N-glycosylation patterns, decreased pollen fertility, and reduced grain yield. These findings indicate that OsPML3 is critical for maintaining Mn homeostasis in the Golgi apparatus to support metabolic processes vital for rice development and reproduction.