Evidence for Independent Genetic Control of the Multiple Forms of Maize Endosperm Branching Enzymes and Starch Synthases
Charles D. Boyer,Jack Preiss +1 more
TLDR
Analysis of extracts from kernels of the double mutant ae du indicated that the two mutants act independently, suggesting that the alterations of the starch may be accounted for by changes in the soluble synthase and branching enzyme fractions.Abstract:
Soluble starch synthase and starch-branching enzymes in extracts from kernels of four maize genotypes were compared. Extracts from normal (nonmutant) maize were found to contain two starch synthases and three branching enzyme fractions. The different fractions could be distinguished by chromatographic properties and kinetic properties under various assay conditions. Kernels homozygous for the recessive amylose-extender (ae) allele were missing branching enzyme IIb. In addition, the citrate-stimulated activity of starch synthase I was reduced. This activity could be regenerated by the addition of branching enzyme to this fraction. No other starch synthase fractions were different from normal enzymes. Extracts from kernels homozygous for the recessive dull (du) allele were found to contain lower branching enzyme IIa and starch synthase II activities. Other fractions were not different from the normal enzymes. Analysis of extracts from kernels of the double mutant ae du indicated that the two mutants act independently. Branching enzyme IIb was absent and the citrate-stimulated reaction of starch synthase I was reduced but could be regenerated by the addition of branching enzyme (ae properties) and both branching enzyme IIa and starch synthase II were greatly reduced (du properties). Starch from ae and du endosperms contains higher amylose (66 and 42%, respectively) than normal endosperm (26%). In addition, the amylopectin fraction of ae starch is less highly branched than amylopectin from normal or du starch. The above observations suggest that the alterations of the starch may be accounted for by changes in the soluble synthase and branching enzyme fractions.read more
Citations
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Journal ArticleDOI
Biochemical and Genetic Analysis of the Effects of Amylose-Extender Mutation in Rice Endosperm
TL;DR: Results strongly suggest that BEIIb plays a specific role in the transfer of short chains, which might then be extended by SS to form the A and B(1) chains of amylopectin cluster in rice endosperm.
Journal ArticleDOI
Endosperm Origin, Development, and Function
TL;DR: In this review, some of the research that has been done on endosperm is summarized, making note of comprehensive reviews and pointing out important questions that remain open to scientific inquiry.
Journal ArticleDOI
Function and Characterization of Starch Synthase I Using Mutants in Rice
Naoko Fujita,Mayumi Yoshida,Noriko Asakura,Takashi Ohdan,Akio Miyao,Hirohiko Hirochika,Yasunori Nakamura +6 more
TL;DR: It is strongly suggested that amylopectin chains are synthesized by the coordinated actions of SSI, SSIIa, and SSIIIa isoforms.
Journal ArticleDOI
Characterization of SSIIIa-Deficient Mutants of Rice: The Function of SSIIIa and Pleiotropic Effects by SSIIIa Deficiency in the Rice Endosperm
Naoko Fujita,Mayumi Yoshida,Tomonori Kondo,Kaori Saito,Yoshinori Utsumi,Takashi Tokunaga,Aiko Nishi,Hikaru Satoh,Jin-Hee Park,Jay-lin Jane,Akio Miyao,Hirohiko Hirochika,Yasunori Nakamura +12 more
TL;DR: Starch synthase IIIa (SSIIIa)-deficient rice (Oryza sativa) mutants were generated using retrotransposon insertion and chemical mutagenesis.
Journal ArticleDOI
Barley sex6 mutants lack starch synthase IIa activity and contain a starch with novel properties.
Matthew K. Morell,Behjat Kosar-Hashemi,Mark Cmiel,Michael S. Samuel,Peter M. Chandler,Sadequr Rahman,Alain Buléon,Ian L Batey,Zhongyi Li +8 more
TL;DR: Analysis of barley shrunken grain mutants has identified lines with a novel high amylose starch phenotype, suggesting the starch synthase IIa (ssIIa) gene as a candidate gene altered by the mutation, and strong evidence for the lesion in the ssIIa gene being the causal mutation for the sex6 phenotype.
References
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Journal ArticleDOI
A revision of the Meyer-Bernfeld model of glycogen and amylopectin.
TL;DR: The regularly rebranched structure originally proposed by Meyer and Bernfeld was the only one of the then existing proposals that could fit the results of exploration of glycogen and amylopectin with debranching enzymes, and the structure shown in fig. 1 has been generally accepted.
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Interaction of spinach leaf adenosine diphosphate glucose α-1, 4-glucan α-4-glucosyl transferase and α-1, 4-glucan α-1, 4-glucan-6-glycosyl transferase in synthesis of branched α-glucan
TL;DR: Both branching enzyme fractions stimulate the previously described “unprimed activity” catalyzed by α-glucan synthetase fraction III about 11- to 14-fold, however, branching enzyme did not stimulate the primed activity.
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Multiple forms of (1 → 4)-α-d-glucan, (1 → 4)-α-d-glucan-6- glycosyl transferase from developing zea mays L. Kernels
Charles D. Boyer,Jack Preiss +1 more
TL;DR: Two major forms of branching enzyme from developing kernels of maize have been detected after DEAE-cellulose chromatography, and combined action of the branching enzymes and rabbit-muscle phosphorylase a resulted in similar patterns of incorporation of d-glucose into the growing α- d -glucan and the synthesis of high molecular-weight polymers.
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Multiple forms of starch branching enzyme of maize: Evidence for independent genetic control
Charles D. Boyer,Jack Preiss +1 more
TL;DR: Purification of starch branching enzymes from kernels of two nonlinked mutants of maize, sugary and amylose-extender, showed the basis of the two mutations to be associated with branching enzymes I and IIb, respectively.
Journal ArticleDOI
Adenosine Diphosphoglucose-Starch Glucosyltransferases from Developing Kernels of Waxy Maize
TL;DR: Two alpha-1,4-glucan alpha-4- glucosyl-transferases were extracted from kernels of waxy maize harvested 22 days after pollination and separated by gradient elution from a diethylaminoethyl-cellulose column, finding that both fractions could utilize amylopectin, amylose, glycogen, maltotriose and maltose as primers.