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The composition of newly synthesized proteins in the endoplasmic reticulum determines the transport pathways of soybean seed storage proteins
Author(s) -
Mori Takashi,
Maruyama Nobuyuki,
Nishizawa Keito,
Higasa Takahiko,
Yagasaki Kazuhiro,
Ishimoto Masao,
Utsumi Shigeru
Publication year - 2004
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2004.02204.x
Subject(s) - endoplasmic reticulum , storage protein , composition (language) , microbiology and biotechnology , chemistry , biochemistry , biology , gene , linguistics , philosophy
Summary Glycinin (11S) and β ‐conglycinin (7S) are major storage proteins in soybean ( Glycine max L.) seeds and accumulate in the protein storage vacuole (PSV). These proteins are synthesized in the endoplasmic reticulum (ER) and transported to the PSV by vesicles. Electron microscopic analysis of developing soybean cotyledons of the wild type and mutants with storage protein composition different from that of the wild type showed that there are two transport pathways: one is via the Golgi and the other bypasses it. Golgi‐derived vesicles were observed in all lines used in this study and formed smooth dense bodies with a diameter of 0.5 to several micrometers. ER‐derived protein bodies (PBs) with a diameter of 0.3–0.5 μ m were observed at high frequency in the mutants containing higher amount of 11S group I subunit than the wild type, whereas they were hardly observed in the mutants lacking 11S group I subunit. These indicate that pro11S group I may affect the formation of PBs. Thus, the composition of newly synthesized proteins in the ER is important in the selection of the transport pathways.