Ultrastructure of prolamin accumulating protein bodies in endosperm ofmutant rice for storage proteins - (Ultrastructure of protein bodies inmutant rice) [Japanese]

摘要

Prolamin, a major storage protein in rice endosperm, is accumulated in rigid protein bodies with layered inner structure, called Protein Body I (PB-I). In this study, ultrastructure of PB-I in the endosperm of mutant rice for storage proteins was examined by transmission electron microscopy (TEM), in order to investigate how the change in polypeptide composition of rice storage proteins affects on the structure of PB-I. Protein bodies in the endosperm of 13 kd-b prolamin-decreased rice (esp-l) were apparently similar to those in usual rice. Mutant rice containing less 13 kd-a and 10 kd prolamins had PB-I with lower density of layer structure and obscure outline compared to esp-l. PB-I of 10 kd-, and 16 kd- polypeptide increased mutant had rigid inner layers with high density. The density of layer structures in PB-I seemed to relate to cysteine content in the storage proteins. In the endosperm of high-gluterin mutant, we found numerous small particles having no layer structure. Those particles seemed to be insufficiently developed PB-I, These results suggested that: firmness of PB-I in rice endosperm was affected by the cysyteine content in prolamin polypeptides, and that promotion of glutelin synthesis might: inhibit: the development of PB-I, [References: 18]