PI21 — Oryza sativa Japonica

Summary

OS04G0401000 (PI21) in rice (Oryza sativa Japonica) on chromosome 4 encodes a protein containing a heavy metal-associated (HMA) domain, which binds metals. This gene is associated with defence responses to fungi, particularly blast disease caused by Magnaporthe oryzae, with observed resistance phenotypes. It is also linked to regulation of defence response to fungi. Beyond disease resistance, PI21 has been associated with agronomic traits including grain number, grain weight, grain yield, panicle number, tiller number, plant height, grain size, cold tolerance, and phenol reaction. Related genes in other species encode HMA domain-containing proteins, though these associations are not established for rice PI21 itself.