scholarly journals PII1: a protein involved in starch initiation that determines granule number and size in Arabidopsis chloroplast

2018 ◽  
Author(s):  
Camille Vandromme ◽  
Corentin Spriet ◽  
David Dauvillée ◽  
Adeline Courseaux ◽  
Jean-Luc Putaux ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Growth Rates ◽  
Starch Granule ◽  
Length Distribution ◽  
Soluble Starch ◽  
Starch Granules ◽  
Wild Type ◽  
Granule Formation ◽  
Chain Length Distribution ◽  
Priming Process

AbstractThe initiation of starch granule formation is still poorly understood. However, soluble starch synthase 4 (SS4) appears to be a major component of this process since it is required to synthetize the correct number of starch granules in the chloroplasts of Arabidopsis thaliana plants. A yeast-2-hybrid screen allowed the identification of several putative SS4 interacting partners. We identified the product of At4g32190 locus as a chloroplast-targeted PROTEIN INVOLVED IN STARCH INITIATION (named PII1). Arabidopsis mutants devoid of PII1 display an alteration of starch initiation process and accumulate, on average, one starch granule per plastid instead of the 5 to 7 granules found in plastids of wild-type plants. These granules are larger than in wild type and they remain flat and lenticular. pii1 mutants display wild-type growth rates and accumulate standard starch amounts. Moreover, starch characteristics, such as amylopectin chain length distribution, remain unchanged. Our results reveal the involvement of PII1 in starch priming process in Arabidopsis leaves through interaction with SS4.

The phenotype of soluble starch synthase IV defective mutants of Arabidopsis thaliana suggests a novel function of elongation enzymes in the control of starch granule formation

2007 ◽  
Vol 49 (3) ◽  
pp. 492-504 ◽  
Author(s):  
Isaac Roldán ◽  
Fabrice Wattebled ◽  
M. Mercedes Lucas ◽  
David Delvallé ◽  
Veronique Planchot ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Starch Granule ◽  
Soluble Starch ◽  
Starch Synthase ◽  
Granule Formation

scholarly journals Miniaturized Analysis of Amylopectin Chain Length Distribution by Fluorescence-Assisted Capillary Electrophoresis (FACE) down to Single Starch Granules

2021 ◽  
Author(s):  
amandine pruvost ◽  
stanislas helle ◽  
nicolas szydlowski ◽  
Christian ROLANDO
Keyword(s):  
Capillary Electrophoresis ◽  
Chain Length ◽  
Solid Phase ◽  
Potato Starch ◽  
Relative Proportion ◽  
Length Distribution ◽  
Fluorescence Analysis ◽  
Starch Granules ◽  
Chain Length Distribution ◽  
Single Granule

In the present work, we developed a miniaturized method for determining amylopectin chain length distribution (CLD) by fluorescence-assisted capillary electrophoresis (FACE). The method relies on single granule entrapping into capillaries followed by direct starch gelatinization and amylopectin debranching on carbograph-based solid phase extraction (SPE) cartridges. Sample desalting on HypersepTM tips following APTS-labelling and the use of nanovials allowed for the fluorescence analysis of weakly diluted samples. Consequently, method sensitivity was improved by 500-fold which is compatible with the analysis of single potato starch granules. The method was implemented to determine CLD profiles of single starch granules ranging from 50 to 100 µm in diameter. In these experiments, the relative proportion of starch glucans of up to 30 degrees of polymerization (DP) could be quantified.

scholarly journals Production of very-high-amylose cassava by post-transcriptional silencing of branching enzyme genes

2018 ◽  
Author(s):  
Wenzhi Zhou ◽  
Shanshan Zhao ◽  
Shutao He ◽  
Qiuxiang Ma ◽  
Xinlu Lu ◽  
...  
Keyword(s):  
Amylose Content ◽  
Length Distribution ◽  
Constitutive Expression ◽  
Raw Material ◽  
Distribution Analysis ◽  
Starch Granules ◽  
Storage Roots ◽  
Chain Length Distribution ◽  
Transgenic Cassava ◽  
High Amylose

AbstractHigh amylose starch, a desired raw material in the starch industry, can be produced by plants deficient in the function of branching enzymes (BEs). Here we report the production of transgenic cassava plants with starches containing up to 50% amylose due to the constitutive expression of hair-pin dsRNAs targeting the BE1 or BE2 genes. A significant decrease in BE transcripts was confirmed in these transgenic plants by quantitative real-time RT-PCR. The absence of BE1 protein in the BE1-RNAi plant lines (BE1i) and a dramatically lower level of BE2 protein in the BE2-RNAi plant lines (BE2i) were further confirmed by Western blot assays. All transgenic plant lines were grown up in the field, but with reduced biomass production of the above-ground parts and storage roots compared to wild type (WT). Considerably high amylose content in the storage roots of BE2i plant lines was achieved, though not in BE1i plant lines. Storage starch granules of BE1i and BE2i plants had similar morphology as WT, however, the size of BE1i starch granules were bigger than that of WT. Comparisons of amylograms and thermograms of all three sources of storage starches revealed dramatic changes to the pasting properties and a higher melting temperature for BE2i starches. Glucan chain length distribution analysis showed a slight increase in chains of DP>36 in BE1i lines and a dramatic increase in glucan chains between DP 10-20 and DP>40 in BE2i lines, compared to that of WT starch. Furthermore, BE2i starches displayed a B-type X-ray diffraction pattern instead of the A-type pattern found in BE1i and WT starches. Therefore, cassava BE1 and BE2 function differently in storage root starch biosynthesis; silencing of cassava BE1 or BE2 caused various changes to starch physico-chemical properties and amylopectin structure. We also report that remarkably high amylose content in cassava starch has been first obtained in transgenic cassava by silencing of BE2 expression, thus showing a high potential for future industrial utilization.

scholarly journals Starch Granule Size and Morphology of Arabidopsis thaliana Starch-Related Mutants Analyzed during Diurnal Rhythm and Development

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5859
Author(s):  
Qingting Liu ◽  
Yuan Zhou ◽  
Joerg Fettke
Keyword(s):  
Arabidopsis Thaliana ◽  
Starch Granule ◽  
Granule Size ◽  
High Temporal Resolution ◽  
Starch Granules ◽  
Transitory Starch ◽  
Young Leaves ◽  
Size And Morphology ◽  
Safranin O

Transitory starch plays a central role in the life cycle of plants. Many aspects of this important metabolism remain unknown; however, starch granules provide insight into this persistent metabolic process. Therefore, monitoring alterations in starch granules with high temporal resolution provides one significant avenue to improve understanding. Here, a previously established method that combines LCSM and safranin-O staining for in vivo imaging of transitory starch granules in leaves of Arabidopsis thaliana was employed to demonstrate, for the first time, the alterations in starch granule size and morphology that occur both throughout the day and during leaf aging. Several starch-related mutants were included, which revealed differences among the generated granules. In ptst2 and sex1-8, the starch granules in old leaves were much larger than those in young leaves; however, the typical flattened discoid morphology was maintained. In ss4 and dpe2/phs1/ss4, the morphology of starch granules in young leaves was altered, with a more rounded shape observed. With leaf development, the starch granules became spherical exclusively in dpe2/phs1/ss4. Thus, the presented data provide new insights to contribute to the understanding of starch granule morphogenesis.

Physiology of Cereal Grain II. Starch Granule Formation in the Developing Barley Kernel

1959 ◽  
Vol 12 (2) ◽  
pp. 146 ◽  
Author(s):  
LH May ◽  
MS Buttrose
Keyword(s):  
Starch Granule ◽  
Dry Weight ◽  
Type A ◽  
Starch Granules ◽  
Type B ◽  
Granule Formation ◽  
Rate Of Increase ◽  
Cereal Grain ◽  
Barley Kernel ◽  
B Granules

Types, numbers, volumes, and weights of starch granules in the barley endosperm were measured at different times from anthesis to maturity. The formation of two types of granule was confirmed: the first (type A) was initiated until 15 days after anthesis; the second (type B) between 18 and 30 days. At maturity there were approximately 10 times as many type B granules as type A, although the latter made up 90 per cent. of the total granule volume. There was a linear relationship between starch granule and endosperm volume throughout kernel development, while the rate of increase in volume per unit granule volume was the same, irrespective of granule size, at anyone time. Starch weight increased as endosperm dry weight increased although the precise form of this relationship is in doubt. The interrelationships between starch granule weight and volume, and also endosperm dry weight and volume, suggest that both starch granules and endosperm increase in density during development.

Expression of bacterial starch-binding domains in Arabidopsis increases starch granule size

2006 ◽  
Vol 33 (3) ◽  
pp. 257 ◽  
Author(s):  
Crispin A. Howitt ◽  
Sadequr Rahman ◽  
Matthew K. Morell
Keyword(s):  
Starch Granule ◽  
Starch Content ◽  
Starch Synthesis ◽  
Length Distribution ◽  
Renewable Resource ◽  
Granule Size ◽  
Parental Line ◽  
In Planta ◽  
Chain Length Distribution ◽  
Binding Domains

Starch is a readily renewable resource that is very widely used for food and industrial purposes; however, greater variation in the functional properties of starch would further extend the use of this biodegradable polymer. Genetic engineering may provide a way to produce designer starches that have the desired properties. Starch-binding domains (SBD) from bacterial enzymes that catabolise starches have the ability to bind two helices of starch and thus have the potential to crosslink starch and / or to be used as anchors for other enzymes that can modify starch properties. In a first step towards novel modification of starch we have investigated the effect of expressing SBDs, singly and in tandem, in planta, and targeting them to the chloroplast in the model plant Arabidopsis thaliana (L.) Heynh. Transgenic plants that contained the SBD from the cyclomaltodextrin glucanotransferase (CGTase) of Thermoanaerobacterium thermosulfurigenes in the chloroplast were produced in both the wild type and the starch excess mutant (sex 1-1) backgrounds. Analysis of starch isolated from the chloroplasts of these lines revealed no significant changes in the amylose : amylopectin ratio, the chain-length distribution of debranched amylopectin or the gelatinisation temperature when compared to the parental line. However, significant changes were observed in the starch granule size with the plants expressing the construct having larger granules. The effect was more pronounced in the sex 1-1 background, and expression of two starch-binding domains linked in tandem had an even greater effect. Despite the starch granules being larger in lines expressing the starch-binding domain, no difference was seen in the starch content of the leaves when compared to parental lines. As the presence of the SBDs in the starch granule only altered granule size, and not other granule properties, they may provide an ideal anchor for targeting starch-modifying enzymes to the site of starch synthesis. This will allow the development of novel modifications of starch during synthesis.

Glucan affinity of starch synthase IIa determines binding of starch synthase I and starch-branching enzyme IIb to starch granules

2012 ◽  
Vol 448 (3) ◽  
pp. 373-387 ◽  
Author(s):  
Fushan Liu ◽  
Nadya Romanova ◽  
Elizabeth A. Lee ◽  
Regina Ahmed ◽  
Martin Evans ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Protein Interactions ◽  
Starch Granule ◽  
Protein Complexes ◽  
Starch Synthase ◽  
Starch Granules ◽  
Branching Enzyme ◽  
Wild Type ◽  
Protein Protein Interactions ◽  
Starch Branching Enzyme

The sugary-2 mutation in maize (Zea mays L.) is a result of the loss of catalytic activity of the endosperm-specific SS (starch synthase) IIa isoform causing major alterations to amylopectin architecture. The present study reports a biochemical and molecular analysis of an allelic variant of the sugary-2 mutation expressing a catalytically inactive form of SSIIa and sheds new light on its central role in protein–protein interactions and determination of the starch granule proteome. The mutant SSIIa revealed two amino acid substitutions, one being a highly conserved residue (Gly522→Arg) responsible for the loss of catalytic activity and the inability of the mutant SSIIa to bind to starch. Analysis of protein–protein interactions in sugary-2 amyloplasts revealed the same trimeric assembly of soluble SSI, SSIIa and SBE (starch-branching enzyme) IIb found in wild-type amyloplasts, but with greatly reduced activities of SSI and SBEIIb. Chemical cross-linking studies demonstrated that SSIIa is at the core of the complex, interacting with SSI and SBEIIb, which do not interact directly with each other. The sugary-2 mutant starch granules were devoid of amylopectin-synthesizing enzymes, despite the fact that the respective affinities of SSI and SBEIIb from sugary-2 for amylopectin were the same as observed in wild-type. The data support a model whereby granule-bound proteins involved in amylopectin synthesis are partitioned into the starch granule as a result of their association within protein complexes, and that SSIIa plays a crucial role in trafficking SSI and SBEIIb into the granule matrix.

Isolation and characterization of eceriferum (cer) mutants induced by T-DNA insertions in Arabidopsis thaliana

Genome ◽  
1993 ◽  
Vol 36 (3) ◽  
pp. 610-618 ◽  
Author(s):  
John P. McNevin ◽  
Wendy Woodward ◽  
Abdelali Hannoufa ◽  
Kenneth A. Feldmann ◽  
Bertrand Lemieux
Keyword(s):  
Arabidopsis Thaliana ◽  
Length Distribution ◽  
Transformation Method ◽  
Epicuticular Wax ◽  
Primary Alcohols ◽  
Chain Length Distribution ◽  
Isolation And Characterization ◽  
Mutant Phenotypes ◽  
Mutant Lines ◽  
Fatty Aldehydes

Thirteen Arabidopsis thaliana mutants with deviating epicuticular wax layers (i.e., cer mutants) were isolated by screening 13 000 transformed lines produced by the seed transformation method. After crossing the 13 mutants to some of the previously known cer mutant lines, 12 of our mutants mapped to 6 of the 21 known complementation groups (cer1 through cer4 as well as cer6 and cer10), while the other mutant corresponded to a previously unknown locus, cer21. Mutant phenotypes of 6 of the 13 mutant lines were caused by T-DNA insertions within cer genes. We also analyzed the chemical composition of the epicuticular wax layers of the cer mutants isolated in this study relative to that of Arabidopsis wild-type plants. Our results suggest that the five genes we tagged regulate different steps in wax biosynthesis, i.e., the decarbonylation of fatty aldehydes to alkanes, the elongation of hexacosanoic acid to octacosanoic acid, the reduction of fatty aldehydes to primary alcohols and the production of free aldehydes, while an insertion in the fifth gene causes an alteration in the chain length distribution of the different classes of wax compounds.Key words: epicuticular wax, glossy mutants, gas chromotography – mass spectroscopy.

scholarly journals Competition between Granule Bound Starch Synthase and Starch Branching Enzyme in Starch Biosynthesis

Rice ◽  
2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Huaxin Han ◽  
Chuantian Yang ◽  
Jihui Zhu ◽  
Lixia Zhang ◽  
Yeming Bai ◽  
...  
Keyword(s):  
Functional Properties ◽  
Length Distribution ◽  
Soluble Starch ◽  
Starch Biosynthesis ◽  
Starch Synthase ◽  
Size Exclusion ◽  
Rice Starch ◽  
Rice Varieties ◽  
Chain Length Distribution ◽  
Granule Bound Starch Synthase

Abstract Background Starch branching enzymes (SBE) and granule-bound starch synthase (GBSS) are two important enzymes for starch biosynthesis. SBE mainly contributes to the formation of side branches, and GBSS mainly contributes for the synthesis of amylose molecules. However, there are still gaps in the understanding of possible interactions between SBE and GBSS. Results Nineteen natural rice varieties with amylose contents up to 28% were used. The molecular structure, in the form of the chain-length distribution (CLDs, the distribution of the number of monomer units in each branch) was measured after enzymatic debranching, using fluorophore-assisted carbohydrate electrophoresis for amylopectin and size- exclusion chromatography for amylose. The resulting distributions were fitted to two mathematical models based on the underlying biosynthetic processes, which express the CLDs in terms of parameters reflecting relevant enzyme activities. Conclusions Finding statistically valid correlations between the values of these parameters showed that GBSSI and SBEI compete for substrates during rice starch biosynthesis, and synthesis of amylose short chains involves several enzymes including GBSSI, SBE and SSS (soluble starch synthase). Since the amylose CLD is important for a number of functional properties such as digestion rate, this knowledge is potentially useful for developing varieties with improved functional properties.

scholarly journals Characterization of wheat lacking B-type starch granules

2021 ◽  
Author(s):  
Benedetta Saccomanno ◽  
Pierre Berbezy ◽  
Kim Findlay ◽  
Jennifer Shoesmith ◽  
Cristobal Uauy ◽  
...  
Keyword(s):  
Starch Granule ◽  
Starch Content ◽  
Starch Granules ◽  
Wild Type ◽  
Bread Making ◽  
Wheat Varieties ◽  
Alcohol Production ◽  
Mutant Lines ◽  
B Granules

ABSTRACTThe physicochemical and agronomical properties of a new form of bread wheat, lacking B-type starch granules (BlessT) was assessed. Three BlessT mutant lines, made by combining homoeologous deletions of BGC1, a gene responsible for the control of B-granule content were compared with two sibling lines with normal starch phenotype and the parent line, cv. Paragon. Quantification of starch granule size and number in developing grain confirmed the lack of small, B-type starch granules throughout development in BlessT. Most starch, flour, grain and loaf characteristics did not vary between BlessT and the wild type sibling controls. However, BlessT starches had higher water absorption, reduced grain hardness and higher protein content, and dough made from BlessT flour required more water and had increased elasticity. Despite the lack of B-granules, BlessT lines do not display a significant decrease in total starch content suggesting that it should be possible to produce commercial wheat varieties that lack B-type starch granules without compromising yield. These findings support the potential utility of this novel type of wheat as a specialist crop in applications ranging from bread making and alcohol production to improved industrial starch products.

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