scholarly journals A Novel Mutation of OsPPDKB, Encoding Pyruvate Orthophosphate Dikinase, Affects Metabolism and Structure of Starch in the Rice Endosperm

2018 ◽  
Vol 19 (8) ◽  
pp. 2268 ◽  
Author(s):  
Long Zhang ◽  
Linglong Zhao ◽  
Lingshang Lin ◽  
Lingxiao Zhao ◽  
Qiaoquan Liu ◽  
...  
Keyword(s):  
Amylose Content ◽  
Novel Mutation ◽  
Starch Content ◽  
Human Life ◽  
Starch Synthesis ◽  
Complementation Test ◽  
Rice Endosperm ◽  
Floury Endosperm ◽  
Pyruvate Orthophosphate Dikinase ◽  
Orthophosphate Dikinase

Starch, as a main energy storage substance, plays an important role in plant growth and human life. Despite the fact that several enzymes and regulators involved in starch biosynthesis have been identified, the regulating mechanism of starch synthesis is still unclear. In this study, we isolated a rice floury endosperm mutant M14 from a mutant pool induced by 60Co. Both total starch content and amylose content in M14 seeds significantly decreased, and starch thermal and pasting properties changed. Compound starch granules were defected in the floury endosperm of M14 seeds. Map-based cloning and a complementation test showed that the floury endosperm phenotype was determined by a gene of OsPPDKB, which encodes pyruvate orthophosphate dikinase (PPDK, EC 2.7.9.1). Subcellular localization analysis demonstrated that PPDK was localized in chloroplast and cytoplasm, the chOsPPDKB highly expressed in leaf and leaf sheath, and the cyOsPPDKB constitutively expressed with a high expression in developing endosperm. Moreover, the expression of starch synthesis-related genes was also obviously altered in M14 developing endosperm. The above results indicated that PPDK played an important role in starch metabolism and structure in rice endosperm.

scholarly journals Triple null mutations in starch synthase SSIIa gene homoeologs lead to high amylose and resistant starch in hexaploid wheat

2020 ◽  
Author(s):  
Adam Schoen ◽  
Anupama Joshi ◽  
Vijay K Tiwari ◽  
Bikram S. Gill ◽  
Nidhi Rawat
Keyword(s):  
Resistant Starch ◽  
Amylose Content ◽  
Starch Content ◽  
Wheat Variety ◽  
Starch Synthesis ◽  
Starch Synthase ◽  
Single Individual ◽  
Individual Genome ◽  
Mutant Genotype ◽  
Knock Out

Abstract Background: Lack of nutritionally appropriate foods is one of the leading causes of obesity in the US and worldwide. Wheat (Triticum aestivum) provides 20% of the calories consumed daily across the globe. The nutrients in the wheat grain come primarily from the starch composed of amylose and amylopectin. Resistant starch content, which is known to have significant human health benefits, can be increased by modifying starch synthesis pathways. Starch synthase enzyme SSIIa, also known as starch granule protein isoform-1 (SGP-1), is integral to the biosynthesis of the branched and readily digestible glucose polymer amylopectin. The goal of this work was to develop a triple null mutant genotype for SSIIa locus in the elite hard red winter wheat variety ‘Jagger’ and evaluate the effect of the knock-out mutations on resistant starch content in grains with respect to wild type. Results: Knock-out mutations in SSIIa in the three genomes of wheat variety ‘Jagger’ were identified using TILLING. Subsequently, these loss-of function mutations on A, B, and D genomes were combined by crossing to generate a triple knockout mutant genotype Jag-ssiia-∆ABD. The Jag-ssiia-∆ABD had an amylose content of 35.70% compared to 31.15% in Jagger, leading to ~118% increase in resistant starch in the Jag-ssiia-∆ABD genotype of Jagger wheat. The single individual genome mutations also had various effects on starch composition. Conclusions: Our full null Jag-ssiia-∆ABD mutant showed a significant increase in RS without the shriveled grain phenotype seen in other ssiia knockouts in elite wheat cultivars. Moreover, this study shows the potential for developing nutritionally improved foods in a non-GM approach. Since all the mutants have been developed in an elite wheat cultivar, their adoption in production and supply will be feasible in future.

scholarly journals Triple null mutations in starch synthase SSIIa gene homoeologs lead to high amylose and resistant starch in hexaploid wheat

2021 ◽  
Author(s):  
Adam Schoen ◽  
Anupama Joshi ◽  
Vijay K Tiwari ◽  
Bikram S. Gill ◽  
Nidhi Rawat
Keyword(s):  
Resistant Starch ◽  
Amylose Content ◽  
Starch Content ◽  
Wheat Variety ◽  
Starch Synthesis ◽  
Starch Synthase ◽  
Single Individual ◽  
Individual Genome ◽  
Mutant Genotype ◽  
Knock Out

Abstract Background: Lack of nutritionally appropriate foods is one of the leading causes of obesity in the US and worldwide. Wheat (Triticum aestivum) provides 20% of the calories consumed daily across the globe. The nutrients in the wheat grain come primarily from the starch composed of amylose and amylopectin. Resistant starch content, which is known to have significant human health benefits, can be increased by modifying starch synthesis pathways. Starch synthase enzyme SSIIa, also known as starch granule protein isoform-1 (SGP-1), is integral to the biosynthesis of the branched and readily digestible glucose polymer amylopectin. The goal of this work was to develop a triple null mutant genotype for SSIIa locus in the elite hard red winter wheat variety ‘Jagger’ and evaluate the effect of the knock-out mutations on resistant starch content in grains with respect to wild type. Results: Knock-out mutations in SSIIa in the three genomes of wheat variety ‘Jagger’ were identified using TILLING. Subsequently, these loss-of function mutations on A, B, and D genomes were combined by crossing to generate a triple knockout mutant genotype Jag-ssiia-∆ABD. The Jag-ssiia-∆ABD had an amylose content of 35.70% compared to 31.15% in Jagger, leading to ~118% increase in resistant starch in the Jag-ssiia-∆ABD genotype of Jagger wheat. The single individual genome mutations also had various effects on starch composition. Conclusions: Our full null Jag-ssiia-∆ABD mutant showed a significant increase in RS without the shriveled grain phenotype seen in other ssiia knockouts in elite wheat cultivars. Moreover, this study shows the potential for developing nutritionally improved foods in a non-GM approach. Since all the mutants have been developed in an elite wheat cultivar, their adoption in production and supply will be feasible in future.

scholarly journals Expression of Maize MADS Transcription Factor ZmES22 Negatively Modulates Starch Accumulation in Rice Endosperm

2019 ◽  
Vol 20 (3) ◽  
pp. 483 ◽  
Author(s):  
Kangyong Zha ◽  
Haoxun Xie ◽  
Min Ge ◽  
Zimeng Wang ◽  
Yu Wang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Mrna Expression ◽  
Starch Content ◽  
Soluble Sugar ◽  
Starch Synthesis ◽  
Synthesis Process ◽  
Starch Accumulation ◽  
Rice Grain ◽  
Altered Expression ◽  
Rice Endosperm

As major component in cereals grains, starch has been one of the most important carbohydrate consumed by a majority of world’s population. However, the molecular mechanism for regulation of biosynthesis of starch remains elusive. In the present study, ZmES22, encoding a MADS-type transcription factor, was modestly characterized from maize inbred line B73. ZmES22 exhibited high expression level in endosperm at 10 days after pollination (DAP) and peaked in endosperm at 20 DAP, indicating that ZmES22 was preferentially expressed in maize endosperm during active starch synthesis. Transient expression of ZmES22 in tobacco leaf revealed that ZmES22 protein located in nucleus. No transactivation activity could be detected for ZmES22 protein via yeast one-hybrid assay. Transformation of overexpressing plasmid 35S::ZmES22 into rice remarkedly reduced 1000-grain weight as well as the total starch content, while the soluble sugar was significantly higher in transgenic rice lines. Moreover, overexpressing ZmES22 reduced fractions of long branched starch. Scanning electron microscopy images of transverse sections of rice grains revealed that altered expression of ZmES22 also changed the morphology of starch granule from densely packed, polyhedral starch granules into loosely packed, spherical granules with larger spaces. Furthermore, RNA-seq results indicated that overexpressing ZmES22 could significantly influence mRNA expression levels of numerous key regulatory genes in starch synthesis pathway. Y1H assay illustrated that ZmES22 protein could bind to the promoter region of OsGIF1 and downregulate its mRNA expression during rice grain filling stages. These findings suggest that ZmES22 was a novel regulator during starch synthesis process in rice endosperm.

scholarly journals Maize endosperm-specific transcription factors O2 and PBF network the regulation of protein and starch synthesis

2016 ◽  
Vol 113 (39) ◽  
pp. 10842-10847 ◽  
Author(s):  
Zhiyong Zhang ◽  
Xixi Zheng ◽  
Jun Yang ◽  
Joachim Messing ◽  
Yongrui Wu
Keyword(s):  
Transcription Factors ◽  
Double Mutant ◽  
Starch Content ◽  
Starch Synthesis ◽  
Starch Synthase ◽  
Maize Endosperm ◽  
Protein Levels ◽  
Pyruvate Orthophosphate Dikinase ◽  
Branching Enzymes ◽  
Critical Components

The maize endosperm-specific transcription factors opaque2 (O2) and prolamine-box binding factor (PBF) regulate storage protein zein genes. We show that they also control starch synthesis. The starch content in the PbfRNAi and o2 mutants was reduced by ∼5% and 11%, respectively, compared with normal genotypes. In the double-mutant PbfRNAi;o2, starch was decreased by 25%. Transcriptome analysis reveals that >1,000 genes were affected in each of the two mutants and in the double mutant; these genes were mainly enriched in sugar and protein metabolism. Pyruvate orthophosphate dikinase 1 and 2 (PPDKs) and starch synthase III (SSIII) are critical components in the starch biosynthetic enzyme complex. The expression of PPDK1, PPDK2, and SSIII and their protein levels are further reduced in the double mutants as compared with the single mutants. When the promoters of these genes were analyzed, we found a prolamine box and an O2 box that can be additively transactivated by PBF and O2. Starch synthase IIa (SSIIa, encoding another starch synthase for amylopectin) and starch branching enzyme 1 (SBEI, encoding one of the two main starch branching enzymes) are not directly regulated by PBF and O2, but their protein levels are significantly decreased in the o2 mutant and are further decreased in the double mutant, indicating that o2 and PbfRNAi may affect the levels of some other transcription factor(s) or mRNA regulatory factor(s) that in turn would affect the transcript and protein levels of SSIIa and SBEI. These findings show that three important traits—nutritional quality, calories, and yield—are linked through the same transcription factors.

scholarly journals Triple null mutations in starch synthase SSIIa gene homoeologs lead to high amylose and resistant starch in hexaploid wheat

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Adam Schoen ◽  
Anupama Joshi ◽  
Vijay Tiwari ◽  
Bikram S. Gill ◽  
Nidhi Rawat
Keyword(s):  
Resistant Starch ◽  
Amylose Content ◽  
Starch Content ◽  
Wheat Variety ◽  
Starch Synthesis ◽  
Starch Synthase ◽  
Single Individual ◽  
Individual Genome ◽  
Mutant Genotype ◽  
Knock Out

Abstract Background Lack of nutritionally appropriate foods is one of the leading causes of obesity in the US and worldwide. Wheat (Triticum aestivum) provides 20% of the calories consumed daily across the globe. The nutrients in the wheat grain come primarily from the starch composed of amylose and amylopectin. Resistant starch content, which is known to have significant human health benefits, can be increased by modifying starch synthesis pathways. Starch synthase enzyme SSIIa, also known as starch granule protein isoform-1 (SGP-1), is integral to the biosynthesis of the branched and readily digestible glucose polymer amylopectin. The goal of this work was to develop a triple null mutant genotype for SSIIa locus in the elite hard red winter wheat variety ‘Jagger’ and evaluate the effect of the knock-out mutations on resistant starch content in grains with respect to wild type. Results Knock-out mutations in SSIIa in the three genomes of wheat variety ‘Jagger’ were identified using TILLING. Subsequently, these loss-of function mutations on A, B, and D genomes were combined by crossing to generate a triple knockout mutant genotype Jag-ssiia-∆ABD. The Jag-ssiia-∆ABD had an amylose content of 35.70% compared to 31.15% in Jagger, leading to ~ 118% increase in resistant starch in the Jag-ssiia-∆ABD genotype of Jagger wheat. The single individual genome mutations also had various effects on starch composition. Conclusions Our full null Jag-ssiia-∆ABD mutant showed a significant increase in RS without the shriveled grain phenotype seen in other ssiia knockouts in elite wheat cultivars. Moreover, this study shows the potential for developing nutritionally improved foods in a non-GM approach. Since all the mutants have been developed in an elite wheat cultivar, their adoption in production and supply will be feasible in future.

scholarly journals Triple null mutations in starch synthase SSIIa gene homoeologs lead to high amylose and resistant starch in hexaploid wheat

2020 ◽  
Author(s):  
Adam Schoen ◽  
Anupama Joshi ◽  
Vijay K Tiwari ◽  
Bikram S. Gill ◽  
Nidhi Rawat
Keyword(s):  
Resistant Starch ◽  
Amylose Content ◽  
Starch Content ◽  
Wheat Variety ◽  
Starch Synthesis ◽  
Starch Synthase ◽  
Single Individual ◽  
Individual Genome ◽  
Mutant Genotype ◽  
Knock Out

Abstract Background: Lack of nutritionally appropriate foods is one of the leading causes of obesity in the US and worldwide. Wheat (Triticum aestivum) provides 20% of the calories consumed daily across the globe. The nutrients in the wheat grain come primarily from the starch composed of amylose and amylopectin. Resistant starch content, which is known to have significant human health benefits, can be increased by modifying starch synthesis pathways. Starch synthase enzyme SSIIa, also known as starch granule protein isoform-1 (SGP-1), is integral to the biosynthesis of the branched and readily digestible glucose polymer amylopectin. The goal of this work was to develop a triple null mutant genotype for SSIIa locus in the elite hard red winter wheat variety ‘Jagger’ and evaluate the effect of the knock-out mutations on resistant starch content in grains with respect to wild type. Results: Knock-out mutations in SSIIa in the three genomes of wheat variety ‘Jagger’ were identified using TILLING. Subsequently, these loss-of function mutations on A, B, and D genomes were combined by crossing to generate a triple knockout mutant genotype Jag-ssiia-∆ABD. The Jag-ssiia-∆ABD had an amylose content of 35.70% compared to 31.15% in Jagger, leading to ~118% increase in resistant starch in the Jag-ssiia-∆ABD genotype of Jagger wheat. The single individual genome mutations also had various effects on starch composition. Conclusions: Our full null Jag-ssiia-∆ABD mutant showed a significant increase in RS without the shriveled grain phenotype seen in other ssiia knockouts in elite wheat cultivars. Moreover, this study shows the potential for developing nutritionally improved foods in a non-GM approach. Since all the mutants have been developed in an elite wheat cultivar, their adoption in production and supply will be feasible in future.

scholarly journals Triple null mutations in starch synthase SSIIa gene homoeologs lead to high amylose and resistant starch in hexaploid wheat

2020 ◽  
Author(s):  
Adam Schoen ◽  
Anupama Joshi ◽  
Vijay K Tiwari ◽  
Bikram S. Gill ◽  
Nidhi Rawat
Keyword(s):  
Resistant Starch ◽  
Amylose Content ◽  
Starch Content ◽  
Wheat Variety ◽  
Starch Synthesis ◽  
Starch Synthase ◽  
Single Individual ◽  
Knockout Mutant ◽  
Individual Genome ◽  
Mutant Genotype

Abstract Background Lack of nutritionally appropriate foods is one of the leading causes of obesity in the US and worldwide. Wheat (Triticum aestivum) provides 20% of the calories consumed daily across the globe. The nutrients in the wheat kernel come primarily from the starch composed of amylose and amylopectin. Resistant starch content, which is known to have significant human health benefits, can be increased by modifying starch synthesis pathways. Starch synthase enzyme SSIIa, also known as starch granule proteins isoform-1 (SGP-1), is integral to the biosynthesis of the branched and readily digestible glucose polymer amylopectin. In this study, a triple knockout mutant genotype (ssiia ∆ ABD) at the SSIIa locus was developed in elite hard red winter wheat variety ‘Jagger’. Results Knock-out mutations in SSIIa in the three genomes of wheat variety ‘Jagger’ were identified using TILLING. Subsequently, these loss-of function mutations on A, B, and D genomes were genetically combined to generate a triple knockout mutant genotype ssiia ∆ ABD. The ssiia ∆ ABD had an amylose content of 35.70% compared to 31.15% in Jagger, leading to ~ 118% increase in resistant starch in the ssiia ∆ ABD genotype of Jagger wheat. The single individual genome mutations also had various effects on starch composition. Conclusions This marks the first time a full null ssiia knockout has been achieved in a single elite cultivar background and shows the potential for developing nutritionally superior foods in a non-GM approach. Since all the mutants have been developed in an elite wheat cultivar, their adoption in production and supply will be easy.

scholarly journals Triple null mutations in starch synthase SSIIa gene homoeologs lead to high amylose and resistant starch in hexaploid wheat

2020 ◽  
Author(s):  
Adam Schoen ◽  
Anupama Joshi ◽  
Vijay K Tiwari ◽  
Bikram S. Gill ◽  
Nidhi Rawat
Keyword(s):  
Resistant Starch ◽  
Amylose Content ◽  
Starch Content ◽  
Wheat Variety ◽  
Starch Synthesis ◽  
Starch Synthase ◽  
Single Individual ◽  
Individual Genome ◽  
Mutant Genotype ◽  
Knock Out

Abstract Background: Lack of nutritionally appropriate foods is one of the leading causes of obesity in the US and worldwide. Wheat (Triticum aestivum) provides 20% of the calories consumed daily across the globe. The nutrients in the wheat grain come primarily from the starch composed of amylose and amylopectin. Resistant starch content, which is known to have significant human health benefits, can be increased by modifying starch synthesis pathways. Starch synthase enzyme SSIIa, also known as starch granule protein isoform-1 (SGP-1), is integral to the biosynthesis of the branched and readily digestible glucose polymer amylopectin. The goal of this work was to develop a triple null mutant genotype for SSIIa locus in the elite hard red winter wheat variety ‘Jagger’ and evaluate the effect of the knock-out mutations on resistant starch content in grains with respect to wild type. Results: Knock-out mutations in SSIIa in the three genomes of wheat variety ‘Jagger’ were identified using TILLING. Subsequently, these loss-of function mutations on A, B, and D genomes were combined by crossing to generate a triple knockout mutant genotype Jag-ssiia-∆ABD. The Jag-ssiia-∆ABD had an amylose content of 35.70% compared to 31.15% in Jagger, leading to ~118% increase in resistant starch in the Jag-ssiia-∆ABD genotype of Jagger wheat. The single individual genome mutations also had various effects on starch composition. Conclusions: Our full null Jag-ssiia-∆ABD mutant showed a significant increase in RS without the shriveled grain phenotype seen in other ssiia knockouts in elite wheat cultivars. Moreover, this study shows the potential for developing nutritionally improved foods in a non-GM approach. Since all the mutants have been developed in an elite wheat cultivar, their adoption in production and supply will be feasible in future.

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