RNAi suppression of xylan synthase genes in wheat starchy endosperm

A - Papers appearing in refereed journals

Wilkinson, M. D., Kosik, O., Halsey, K., Walpole, H., Evans, J., Wood, A. J., Ward, J. L., Mitchell, R. A. C., Lovegrove, A. and Shewry, P. R. 2021. RNAi suppression of xylan synthase genes in wheat starchy endosperm. PLOS ONE. 16 (8), p. e0256350. https://doi.org/10.1371/journal.pone.0256350

AuthorsWilkinson, M. D., Kosik, O., Halsey, K., Walpole, H., Evans, J., Wood, A. J., Ward, J. L., Mitchell, R. A. C., Lovegrove, A. and Shewry, P. R.
Abstract

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.

KeywordsWheat; Cell walls; Dietary fibre; RNAi suppression; Arabinoxylan
Year of Publication2021
JournalPLOS ONE
Journal citation16 (8), p. e0256350
Digital Object Identifier (DOI)https://doi.org/10.1371/journal.pone.0256350
Open accessPublished as ‘gold’ (paid) open access
FunderBiotechnology and Biological Sciences Research Council
Funder project or codeDesigning Future Wheat (DFW) [ISPG]
Publisher's version
Accepted author manuscript
Output statusPublished
Publication dates
Online19 Aug 2021
Publication process dates
Accepted04 Aug 2021
PublisherPublic Library of Science (PLOS)
ISSN1932-6203

Permalink - https://repository.rothamsted.ac.uk/item/98657/rnai-suppression-of-xylan-synthase-genes-in-wheat-starchy-endosperm

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