The Lack Of The Extracellular Domain Of A Rice Putative Receptor, DENSE PANICLE 1, Causes Semi-Dwarfness And Increase Of Spikelets Per Plant.

Abstract

In cereal breeding, semi-dwarfness is a favorable character since it decreases the risk that panicles fall down to the ground. We show that rice dense panicle 1 (dn1 ) plant is semi-dwarf, and that it increases its potential grain weight per plant. The dn1 plant decreased weight of each grain, whereas number of spikelets (grains) per plant increased. This gene has been utilized in breeding of japonica high-yield varieties in China in last 50 years. Cells and various organs were shorter and wider in dn1 plant. Response of dn1 plant to brassinosteroid, gibberellin, cytokinin or auxin was not different from that of wild type. Cloned DN1 was mainly expressed in primordia of leafy organs. DN1 protein fused to sGFP localized to the cell membrane, and that intracellular region localized not only to the membrane but nuclear. DN1 lacking the extracellular region, which caused the dn1 phenotypes, localized only to the membrane.