Reference "Changes in structure of starch and enzyme activities affected by sugary mutations in developing rice endosperm. Possible role of starch debranching enzyme (R-enzyme) in amylopectin biosynthesis"

Reference ID

7037

Title

Changes in structure of starch and enzyme activities affected by sugary mutations in developing rice endosperm. Possible role of starch debranching enzyme (R-enzyme) in amylopectin biosynthesis

Source

Physiologia Plantarum, 1996, vol. 97, pp. 491-498

Authors (6)

Nakamura-Y	Umemoto-T
Takahata-Y	Komae-K
Amano-E	Satoh-H

Abstract

In maturing endosperms of a variety of sugary mutants of rice, phytoglycogen-
like polysaccharides with highly branched alpha-glucans were accumulated instead
of amylopectin, while the amylose content greatly decreased. Measurement of
activities per endosperm of the 10 major enzymes involved in starch and sucrose
metabolism revealed that the activity of starch debranching enzyme (R-enzyme)
was specifically reduced in the sugary mutants. The activity of starch branching
enzyme I (Q-enzyme I) was also significantly decreased, but less so than the R-
enzyme, in the mutants, suggesting some coordination of the expression of the
genes coding for R-enzyme and Q-enzyme I.