Genetic elimination of a starch granule protein, SGP-1, of wheat generates an altered starch with apparent high amylose

Yamamori, Makoto; Fujita, Shuzo; Hayakawa, Katsuyuki; Matsuki, Junko; Yasui, Takeshi

doi:10.1007/s001220051444

Cited by 229 publications

(224 citation statements)

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“…The iodine affinity (IA) of defatted starch was 1.4 fold higher for the SGP 1 null starch, resulting in a higher value of apparent amylose content for the SGP 1 null starch than for normal starch. The higher amylose content for the null mutant starch agreed with the previous study, 6) in which amylose content measured by an amperometric titration method was reported to be 37.3 and 29.3% for the SGP 1 null and normal starch, respectively. Higher amylose content for the SGP 1 null starch was partly due to IA of amylopectin being three fold higher for the mutant.…”

Section: Iodine Affinities and Amylose Contentssupporting

confidence: 91%

“…6) Amylose and amylopectin were fractionated from defatted starch by the method of Takeda et al . 7) Pseudomonas isoamylase was a product of Hayashi-…”

Section: Methodsmentioning

confidence: 99%

“…3,5) Yamamori et al . 6) generated a mutant line that lacked all three isoforms of SGP 1 and reported that starch granules from the SGP 1 null mutant have altered properties, such as absence of birefringence under polarized light, absence of diffraction of X ray (crystallinity of starch granules), and an increased amylose content. Effects on molecular structures were also examined, and high performance size exclusion chromatography (HPSEC) and high performance anion exchange chromatography with pulsed amperometric detection (HPAEC PAD) revealed that chain length distribution of amylopectin was significantly altered by the mutation.…”

mentioning

confidence: 99%

“…Effects on molecular structures were also examined, and high performance size exclusion chromatography (HPSEC) and high performance anion exchange chromatography with pulsed amperometric detection (HPAEC PAD) revealed that chain length distribution of amylopectin was significantly altered by the mutation. 6) However, the elucidation of structural changes was limited to a certain extent because the structural characterization was carried out without fractionation of starch into amylose and amylopectin, and consequently changes occurring in amylose were not examined at all. In this study, amylose and amylopectin were fractionated from SGP 1 null starch and their molecular structures were examined in more detail and compared with those of a wheat starch with normal amylose content (cv.…”

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Increased Amylose Content and Altered Molecular Structures of Wheat Starch by SGP-1 Null Mutation

勲¹,

育雄²,

誠³

et al. 2004

J. Appl. Glycosci.

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Starch biosynthesis is a complex, concerted process by various enzymes, involving elongation of an existing 1,4 glucoside chain, branching of glucoside chains by forming 1,6 linkages and debranching by hydrolysis of 1,6 linkages. Some of these enzymes are found to be bound to or trapped in starch granules. In wheat (Triticum aestivum L.), at least three proteins, other than waxy protein, have been identified as starch granule bound proteins (starch granule protein, SGP) 1,2) and are designated as SGP 1, 2 and 3. 1) The SGPs are thought to be isoforms of starch synthase II, starch branching enzyme II and starch synthase I, respectively, based on their biochemical properties and nucleotide sequence. 2 5) Three isoforms with different molecular weight (100 115 kDa 2 5) ) of SGP 1 are present in wheat starch granules and they are designated SGP A1, B1, D1, 1) each encoded at loci on the short arms o f chromosome 7A, 7 B and 7 D , respectively . 1,2) SGP B1, and very likely the other two isofomrs also, exist in both starch granule and soluble fractions at early stages of endosperm development but at late stages they are exclusively granule bound. 3,5) Yamamori et al . 6) generated a mutant line that lacked all three isoforms of SGP 1 and reported that starch granules from the SGP 1 null mutant have altered properties, such as absence of birefringence under polarized light, absence of diffraction of X ray (crystallinity of starch granules), and an increased amylose content. Effects on molecular structures were also examined, and high performance size exclusion chromatography (HPSEC) and high performance anion exchange chromatography with pulsed amperometric detection (HPAEC PAD) revealed that chain length distribution of amylopectin was significantly altered by the mutation. 6) However, the elucidation of structural changes was limited to a certain extent because the structural characterization was carried out without fractionation of starch into amylose and amylopectin, and consequently changes occurring in amylose were not examined at all. In this study, amylose and amylopectin were fractionated from SGP 1 null starch and their molecular structures were examined in more detail and compared with those of a wheat starch with normal amylose content (cv. Chinese Spring). MATERIALS AND METHODS Materials.Starches were the same specimens used in a previous study. 6) Amylose and amylopectin were fractionated from defatted starch by the method of Takeda et al . 7) Pseudomonas isoamylase was a product of Hayashi- Abstract: Amylose content and molecular structures of starch from a mutant of wheat (Triticum aestivum L.) that lacks a starch granule bound protein, SGP-1, have been compared with those from normal wheat (cv. Chinese Spring). Actual amylose contents, calculated by taking iodine affinity of amylopectin into consideration, for the mutant (SGP-1 null) and normal wheat starches were 34 and 26%, respectively. The amylopectins from SGP-1 null and normal starches had number-average degree of polymerization (DPn) of 4200 ...

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Section: Iodine Affinities and Amylose Contentssupporting

confidence: 91%

“…6) Amylose and amylopectin were fractionated from defatted starch by the method of Takeda et al . 7) Pseudomonas isoamylase was a product of Hayashi-…”

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Increased Amylose Content and Altered Molecular Structures of Wheat Starch by SGP-1 Null Mutation

勲¹,

育雄²,

誠³

et al. 2004

J. Appl. Glycosci.

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“…One of these enzymes, starch synthase IIa (SSIIa), is thought to be involved in elongating the short chains of amylopectin (James et al, 2003). The wheat high amylose (HA) mutant, which lacks SSIIa, produces amylopectin with an increased level of short chains and a reduced level of intermediate chains, and contains approximately 1.3-fold more amylose than wild-type wheat (Yamamori et al, 2000;Hanashiro et al, 2004). These Wx and HA types were used as parents in a cross to produce the sweet wheat (SW) double mutant ( Table 1).…”

Section: Textmentioning

confidence: 99%

Sweet Wheat

et al. 2006

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The major components of storage starch are amylose and amylopectin, and in wheat, both an amylose-free mutant lacking granule-bound starch synthase I and a high-amylose mutant lacking starch synthase IIa have been produced recently. Here, we report the production of an amylose-free/ high-amylose double mutant. This double mutant has kernel and carbohydrate characteristics that are remarkably different than those of either single mutant, including a dramatically shrunken seed shape. Surprisingly, the double mutant has maltose and sucrose levels that are high enough to make it worthy of being called "sweet wheat".

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Starch Properties of a Waxy Mutant Line of Hull-less Barley (Hordeum vulgare L.)

et al. 2002

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Endosperm starch isolated from an amylose-free waxy mutant hull-less barley line, Shikoku Hadaka 97, had an amylose content of 0.3% and higher swelling power than ordinary waxy barley cultivars/lines with amylose contents of 2.2-6.5%. A highly significant correlation was observed between amylose content and swelling power among waxy barley starches. No clear differences were detected in the chain-length distribution profiles or thermal properties between the amylose-free starch and ordinary waxy starch. The chain-length distribution profile of waxy barley starch was slightly different from that of normal barley starch. Gelatinization temperatures and gelatinization enthalpy of waxy barley starch were higher than those of normal barley starch. Significant correlations were observed between amylose content and thermal properties of starch samples analyzed. Waxy barley starch stained with a concentrated iodine-potassium iodide solution showed a ghost-like appearance.

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Genetic elimination of a starch granule protein, SGP-1, of wheat generates an altered starch with apparent high amylose

Cited by 229 publications

References 36 publications

Increased Amylose Content and Altered Molecular Structures of Wheat Starch by SGP-1 Null Mutation

Increased Amylose Content and Altered Molecular Structures of Wheat Starch by SGP-1 Null Mutation

Sweet Wheat

Starch Properties of a Waxy Mutant Line of Hull-less Barley (Hordeum vulgare L.)

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