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Is there an alternative pathway for starch biosynthesis in cereal seeds? |
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Villand P, Kleczkowski LA
Is there an alternative pathway for starch biosynthesis in cereal seeds?
Zeitschrift für Naturforschung: 1994 49c:215-219
Abstract:
A hypothesis is presented
concerning a putative extra-amyloplastic location of barley seed
endosperm ADP-glucose pyrophosphorylase (AGPase), a key enzyme of
starch biosynthesis. The hypothesis is based both on indirect and
direct evidence obtained in our laboratory as well as on data of other
investigators. It is proposed that ADP-glucose formed by the
extra-amyloplastic enzyme is transported to the amyloplasts via an
ADP-glucose carrier in the plastid membrane, and then is utilized by
the starch biosynthesizing machinery of these organelles. In addition
to the extra-amyloplastic form of AGPase, barley endosperm contains
also a second isozyme of AGPase, located in the amyloplasts. Presence
of isozymes of AGPase in cereal seed endosperm is consistent with
biochemical, molecular and genetic data on starch biosynthesis in this
tissue.
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UPSC på Svenska 
Publications 1994 
