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 The Physicochemical Properties of Starch Are Affected by Wxlv in Indica Rice

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3089
Author(s):  
Linhao Feng ◽  
Chenya Lu ◽  
Yong Yang ◽  
Yan Lu ◽  
Qianfeng Li ◽  
...  
Keyword(s):  
Fine Structure ◽  
Grain Quality ◽  
Amylose Content ◽  
Indica Rice ◽  
Length Distribution ◽  
Rice Grain ◽  
Distribution Analysis ◽  
Near Isogenic Lines ◽  
Chain Length Distribution ◽  
Isogenic Lines

Amylose largely determines rice grain quality profiles. The process of rice amylose biosynthesis is mainly driven by the waxy (Wx) gene, which also affects the diversity of amylose content. The present study assessed the grain quality profiles, starch fine structure, and crystallinity characteristics of the near-isogenic lines Q11(Wxlv), NIL(Wxa), and NIL(Wxb) in the indica rice Q11 background containing different Wx alleles. Q11(Wxlv) rice contained a relatively higher amylose level but very soft gel consistency and low starch viscosity, compared with rice lines carrying Wxa and Wxb. In addition, starch fine structure analysis revealed a remarkable decrease in the relative area ratio of the short amylopectin fraction but an increased amylose fraction in Q11(Wxlv) rice. Chain length distribution analysis showed that Q11(Wxlv) rice contained less amylopectin short chains but more intermediate chains, which decreased the crystallinity and lamellar peak intensity, compared with those of NIL(Wxa) and NIL(Wxb) rice. Additionally, the starches in developing grains showed different accumulation profiles among the three rice lines. Moreover, significant differences in starch gelatinization and retrogradation characteristics were observed between near-isogenic lines, which were caused by variation in starch fine structure. These findings revealed the effects of Wxlv on rice grain quality and the fine structure of starch in indica rice.

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.

Melting the secrets of gelatinisation temperature in rice

2010 ◽  
Vol 37 (5) ◽  
pp. 439 ◽  
Author(s):  
Rosa P. Cuevas ◽  
Venea D. Daygon ◽  
Henry M. Corpuz ◽  
Leilani Nora ◽  
Russell F. Reinke ◽  
...  
Keyword(s):  
Amylose Content ◽  
Oryza Sativa L ◽  
Length Distribution ◽  
Cooking Time ◽  
Scanning Calorimetry ◽  
Rice Varieties ◽  
Chain Length Distribution ◽  
Chain Lengths ◽  
Major Grouping ◽  
Upper Boundary

Gelatinisation temperature (GT) is one of the key traits measured in programs for breeding rice (Oryza sativa L.). It is commonly estimated by the alkali spreading value (ASV), and less commonly by differential scanning calorimetry (DSC). Using a diverse set of germplasm, it was determined that DSC values associate poorly with ASV, are not correlated with amylose content but correlate with cooking time. Rice varieties are traditionally grouped into three classes of GT based on ASV: high, intermediate and low. However, the distribution of DSC values of 4000 samples shows only two classes: high and low. Large differences in the distributions of chain lengths synthesised by starch synthase IIa (SSIIa) support the two classes as the major grouping, two haplotypes associating with each peak. Each peak of DSC values spanned 10°C. The chain length distribution of the amylopectin molecules from varieties at the upper boundary of each peak showed significantly more chains that span both the crystalline and amorphous lamellae of a cluster than varieties at the other end of that distribution. Improved varieties, classified as intermediate GT by ASV, belong to both of the classes defined by DSC, implying that some enzyme, other than SSIIa is involved in intermediate GT.

scholarly journals Potentials of Edible Canna (Canna edulis Kerr) Starch for Bioplastic: A Review

2021 ◽  
Vol 10 (2) ◽  
pp. 182-191
Author(s):  
Azmi Alvian Gabriel ◽  
◽  
Anggita Fitri Solikhah ◽  
Alifia Yuanika Rahmawati ◽  
Yunita Sasmi Taradipa ◽  
...  
Keyword(s):  
Mineral Content ◽  
Raw Materials ◽  
Amylose Content ◽  
Experimental Studies ◽  
Raw Material ◽  
Carbohydrate Source ◽  
Polybutylene Succinate ◽  
Treatment Use ◽  
High Amylose ◽  
Short Time

Starch-based bioplastic was more economical and competitive compared to bacteria-based bioplastics (polylactic acid, polybutylene succinate, and polyhydroxyalkanoates) due to the starch variances and the availability in Indonesia, along with the simple techniques that can be applied. This review aimed to describe the potential and opportunities of edible canna starch as an alternative raw material of bioplastics production. Edible canna tuber productivity in Java, Indonesia, with a harvest age of about eight months reaches 30-49.4 tons/ha. It will produce a mature segment 70.2% of the total harvest weight. Edible canna tuber was a carbohydrate source that contains 88.10% starch with an advantage of 68% higher fiber and mineral content than other tubers. Furthermore, canna tuber starch contains amylose proportions of 35.0%. The high amylose content in canna starch is one of the properties that can position its function for developing packaging materials. The gelatinization process of canna starch requires a short time and low energy because of its large granule size (56 μm). A literature review of canna starch as an alternative of bioplastic raw materials needs to be carried out to obtain accurate data and information regarding treatment, use of additional materials, and characteristics of bioplastic products resulting from experimental studies so that they can be further implemented.

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 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.

scholarly journals Functionality of cassava genotypes for waxy starch

2021 ◽  
Vol 56 ◽  
Author(s):  
Thaís Barbosa dos Santos ◽  
Carlos Wanderlei Piler de Carvalho ◽  
Luciana Alves de Oliveira ◽  
Eder Jorge de Oliveira ◽  
Flávia Villas-Boas ◽  
...  
Keyword(s):  
Amylose Content ◽  
Length Distribution ◽  
Principal Component ◽  
Scanning Calorimetry ◽  
Strong Negative Correlation ◽  
Chain Length Distribution ◽  
Crystallinity Degree ◽  
Waxy Maize ◽  
Waxy Starch ◽  
Paste Viscosity

Abstract: The objective of this work was to select cassava (Manihot esculenta) genotypes from the Brazilian germplasm bank with a functionality similar to that of waxy starch. A total of 881 genotypes were pre-selected using principal component analysis and hierarchical clustering, and their industrial potential was compared with that of the 7745-5WX waxy cassava and the WX-Maize waxy maize clones, both used as references. Two genotypes stood out: BGM0036 and BGM0083. Samples from these four genotypes were characterized by means of amylose content, scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, paste viscosity, and chain-length distribution of amylopectin. The samples presented A-type crystallinity and no statistical differences (p > 0.05) regarding crystallinity degree (25.3 to 30.0), which shows similar proportions of the amylose/amylopectin fractions. No differences were observed in the microstructure of the cassava starches. Initial gelatinization temperature and amylopectin short chains presented a very strong negative correlation, indicating that a lower proportion of short chains of amylopectin results in a higher initial temperature of gelatinization. BGM0036 and BGM0083 show a low final viscosity, close to that of the waxy maize and cassava starches, being an alternative for use in different foods that require stability during freezing.

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