Abstract
Rice prolamines consist of two major polypeptides such as the cystein-rich and cystein-poor prolamines and they form protein body (PB) within the lumen of rough endoplasmic reticulum. We observed prolamine PBs in the developing rice endosperm by immunocytochemical analysis using anti-10 kDa prolamine (Cys-rich) and anti-13 kDa prolamine (cys-poor) antiserums. These results demonstrated that rice prolamine PB formation is initiated by 10 kDa prolamines accumulation at the core, sequentially 13 kDa prolamines are layered over the core and formed periphery layer. In the 13 kDa prolamine deficient mutant, spherical PBs with the core made up with 10 kDa prolamines were observed. But, these cores couldn't be found in the 10 kDa prolamine deficient mutants. Instead, irregular and hypertrophied PBs were formed, suggesting that these PBs are fragile in intra-structure. We concluded that 10 kDa prolamines play a role to form the core to stabilize PB structure in rice.
