Summary
The seed storage proteins of maize (Zea mays L.) are synthesized during endosperm development on membrane-bound polyribosomes. These proteins, collectively called zeins, are translocated into the lumen of the rough endoplasmic reticulum, where they assemble into protein bodies. Protein body formation in normal genotypes occurs via an ordered deposition of the various types of zeins, and leads to the formation of spherical structures with a diameter of about 1 μm. These structures consist of a central core that contains predominantly α-zein; this central region is surrounded by a peripheral layer of β- and γ-zeins, and the entire structure is bounded by rough endoplasmic reticulum.
In the endosperm mutant floury-2 the levels of all classes of zeins are reduced; these kernels exhibit an opaque phenotype instead of the vitreous phenotype observed in normal genotypes. In contrast to the discrete, spherical protein bodies which are formed in normal maize endosperm, the protein bodies within floury-2 endosperm are irregular and the zeins are disorganized; patches of β- and γ-zeins occur within irregularly lobed clusters of α-zein within the lumen of the rough endoplasmic reticulum. The implications of this aberrant distribution are discussed, both with respect to protein body development and kernel characteristics.
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Abbreviations
- BSA:
-
bovine serum albumin
- DAP:
-
days after pollination
- IgG:
-
immunoglobulin G
References
Christianson DD, Khoo U, Nielsen HC, Wall S (1974) Influence ofopaque-2 andfluory-2 genes on formation of proteins in particulates of corn endosperm. Plant Physiol 53: 851–855
Fontes EBP, Shank BB, Wrobel RL, Moose SP, O' Brian GR, Wurtzel ET, Boston RS (1991) Characterization of an immunoglobulin binding protein homolog in the maize floury-2 endosperm mutant. Plant Cell 3: 483–496
Geetha KB, Lending CR, Lopes MA, Wallace JC, Larkins BA (1991)Opaque-2 modifiers increase gamma-zein synthesis and alter its spatial distribution in maize endosperm. Plant Cell 3: 1207–1219
Hayat MA (1989) Principles and techniques of electron microscopy: biological applications, 3rd edn. CRC Press, Boca Raton
Jones RA (1978) Effects offloury-2 locus on zein accumulation and RNA metabolism during maize endosperm development. Biochem Genet 16: 27–38
Khoo U, Wolf MJ (1970) Origin and development of protein granules in maize endosperm. Amer J Bot 57: 1042–1050
Larkins BA, Hurkman WJ (1978) Synthesis and deposition of zein in protein bodies of maize endosperm. Plant Physiol 62: 256–263
—, Lending CR, Wallace JC, Galili G, Kawata EE, Geetha KB, Martin DN, Bracker CE (1989) Zein gene expression during maize endosperm development. In: Goldberg RB (ed) The molecular basis of plant development. AR Liss, New York, pp 109–120
Lending CR, Larkins BA (1989) Changes in the zein composition of protein bodies during maize endosperm development. Plant Cell 1: 1011–1023
—, Kriz AL, Larkins BA, Bracker CE (1988) Structure of maize protein bodies and immunocytochemical localization of zeins. Protoplasma 143: 51–62
Lopes MA, Larkins BA (1991) Isolation of an alcohol-soluble glycine-rich protein from maize protein bodies. Plant Physiol 96: 121
Wallace JC, Lopes MA, Paiva E, Larkins BA (1990) New methods for extraction and quantitiation of zeins reveal a high content of gamma-zein in modified opaque-2 maize. Plant Physiol 92: 191–196
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Lending, C.R., Larkins, B.A. Effect of thefloury-2 locus on protein body formation during maize endosperm development. Protoplasma 171, 123–133 (1992). https://doi.org/10.1007/BF01403727
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DOI: https://doi.org/10.1007/BF01403727