Changes in the arabinoxylan fraction of wheat grain during alcohol production

Kosík, Ondřej; Powers, Stephen J.; Chatzifragkou, Afroditi; Prabhakumari, Parvathy Chandran; Charalampopoulos, Dimitris; Hess, Linde; Brosnan, James M.; Shewry, Peter R.; Lovegrove, Alison

doi:10.1016/j.foodchem.2016.10.109

Cited by 16 publications

(9 citation statements)

References 38 publications

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“…AXOS and glucans were separated and chromatograms analysed as described by (Kosik et al, 2017). Integrated peak areas were recorded for each AXOS and for G3 and G4 peaks derived from (1-3):(1-4)-b-D-glucan and the ratio of peak area in transgenic lines to that in corresponding azygous control lines calculated.…”

Section: Analysis Of Arabinoxylan (Ax) and (1-3):(1-4)-b-d-glucan Conmentioning

confidence: 99%

Feruloylation and structure of arabinoxylan in wheat endosperm cell walls from RNAi lines with suppression of genes responsible for backbone synthesis and decoration

Freeman

Ward

Kosík

et al. 2017

Plant Biotechnology Journal

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SummaryArabinoxylan (AX) is the major component of the cell walls of wheat grain (70% in starchy endosperm), is an important determinant of end‐use qualities affecting food processing, use for animal feed and distilling and is a major source of dietary fibre in the human diet. AX is a heterogeneous polysaccharide composed of fractions which can be sequentially extracted by water (WE‐AX), then xylanase action (XE‐AX) leaving an unextractable (XU‐AX) fraction. We determined arabinosylation and feruloylation of AX in these fractions in both wild‐type wheat and RNAi lines with decreased AX content (TaGT43_2 RNAi, TaGT47_2 RNAi) or decreased arabinose 3‐linked to mono‐substituted xylose (TaXAT1 RNAi). We show that these fractions are characterized by the degree of feruloylation of AX, <5, 5–7 and 13–19 mg bound ferulate (g−1 AX), and their content of diferulates (diFA), <0.3, 1–1.7 and 4–5 mg (g−1 AX), for the WE, XE and XU fractions, respectively, in all RNAi lines and their control lines. The amount of AX and its degree of arabinosylation and feruloylation were less affected by RNAi transgenes in the XE‐AX fraction than in the WE‐AX fraction and largely unaffected in the XU‐AX fraction. As the majority of diFA is associated with the XU‐AX fraction, there was only a small effect (TaGT43_2 RNAi, TaGT47_2 RNAi) or no effect (TaXAT1 RNAi) on total diFA content. Our results are compatible with a model where, to maintain cell wall function, diFA is maintained at stable levels when other AX properties are altered.

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Section: Analysis Of Arabinoxylan (Ax) and (1-3):(1-4)-b-d-glucan Conmentioning

confidence: 99%

Feruloylation and structure of arabinoxylan in wheat endosperm cell walls from RNAi lines with suppression of genes responsible for backbone synthesis and decoration

Freeman

Ward

Kosík

et al. 2017

Plant Biotechnology Journal

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“…Arabinoxylan and β-glucan structures were determined by enzyme fingerprinting [ 22 ]. Briefly, 100 mg of wheat flour was resuspended in 1 mL of 80% ethanol (v/v) and heated at 95°C for 10 min to inactivate endogenous glycosyl hydrolyses.…”

Section: Methodsmentioning

confidence: 99%

RNAi suppression of xylan synthase genes in wheat starchy endosperm

et al. 2021

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The xylan backbone of arabinoxylan (AX), the major cell wall polysaccharide in the wheat starchy endosperm, is synthesised by xylan synthase which is a complex of three subunits encoded by the GT43_1, GT43_2 and GT47_2 genes. RNAi knock-down of either GT43_1 or all three genes (triple lines) resulted in decreased AX measured by digestion with endoxylanase (to 33 and 34.9% of the controls) and by monosaccharide analysis (to 45.9% and 47.4% of the controls) with greater effects on the amount of water-extractable AX (to 20.6 and 19.9% of the controls). Both sets of RNAi lines also had greater decreases in the amounts of substituted oligosaccharides released by digestion of AX with endoxylanase than in fragments derived only from the xylan backbone. Although the GT43_1 and triple lines had similar effects on AX they did differ in their contents of soluble sugars (increased in triple only) and on grain size (decreased in triple only). Both sets of transgenic lines had decreased grain hardness, indicating effects on cell wall mechanics. These results, and previously published studies of RNAi suppression of GT43_2 and GT47_2 and of a triple mutant of GT43_2, are consistent with the model of xylan synthase comprising three subunits one of which (GT47_2) is responsible for catalysis with the other two subunits being required for correct functioning but indicate that separate xylan synthase complexes may be responsible for the synthesis of populations of AX which differ in their structure and solubility.

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“…Animal nutrition is the opposite, in that too much dietary fibre interferes with rapid growth of the animal, particularly in monogastrics such as pigs and poultry (de Vries et al, 2012;Rosenfelder et al, 2013;Koegelenberg and Chimphango, 2017;Alyassin and Campbell, 2019). DDGS is the major animal feed co-product of bioethanol production, as shown in Figure 2, and is high in dietary fibre that is mostly AX (Srinivasan et al, 2008;Rosenfelder et al, 2013;Chatzifragkou et al, 2015;Kosik et al, 2017;Chatzifragkou and Charalampopoulos, 2018). Extracting AX reduces the fibre content of DDGS and enhances its value as animal feed.…”

Section: Arabinoxylans Integrated With Bioethanol Productionmentioning

confidence: 99%