Reference "Germin, a protein marker of early plant development, is an oxalate oxidase"

Reference ID

8712

Title

Germin, a protein marker of early plant development, is an oxalate oxidase

Source

The Journal of biological chemistry, 1993, vol. 268, pp. 12239-12242

Authors (5)

Lane-B-G	Dunwell-J-M
Ray-J-A	Schmitt-M-R
Cuming-A-C

Abstract

Germin is a homopentameric glycoprotein, the synthesis of which coincides with
the onset of growth in germinating wheat embryos. There have been detailed
studies of germin structure, biosynthesis, homology with other proteins, and of
its value as a marker of wheat development. Germin isoforms associated with the
apoplast have been speculated to have a role in embryo hydration during
maturation and germination. Antigenically related isoforms of germin are present
during germination in all of the economically important cereals studied, and the
amounts of germin-like proteins and coding elements have been found to undergo
conspicuous change when salt-tolerant higher plants are subjected to salt
stress. In this report, we describe how circumstantial evidence arising from
unrelated studies of barley oxalate oxidase and its coding elements have led to
definitive evidence that the germin isoform made during wheat germination is an
oxalate oxidase. Establishment of links between oxalate degradation, cereal
germination, and salt tolerance has significant implications for a broad range
of studies related to development and adaptation in higher plants. Roles for
germin in cell wall biochemistry and tissue remodeling are discussed, with
special emphasis on the generation of hydrogen peroxide during germin-induced
oxidation of oxalate.