RNAi suppression of xylan synthase genes in wheat starchy endosperm.

Autor: Wilkinson MD; Plant Science Department, Rothamsted Research, Harpenden, United Kingdom., Kosik O; Plant Science Department, Rothamsted Research, Harpenden, United Kingdom., Halsey K; Computational and Analytical Sciences, Rothamsted Research, Harpenden, United Kingdom., Walpole H; Computational and Analytical Sciences, Rothamsted Research, Harpenden, United Kingdom., Evans J; Computational and Analytical Sciences, Rothamsted Research, Harpenden, United Kingdom., Wood AJ; Plant Science Department, Rothamsted Research, Harpenden, United Kingdom., Ward JL; Computational and Analytical Sciences, Rothamsted Research, Harpenden, United Kingdom., Mitchell RAC; Plant Science Department, Rothamsted Research, Harpenden, United Kingdom., Lovegrove A; Plant Science Department, Rothamsted Research, Harpenden, United Kingdom., Shewry PR; Plant Science Department, Rothamsted Research, Harpenden, United Kingdom.
Jazyk: angličtina
Zdroj: PloS one [PLoS One] 2021 Aug 19; Vol. 16 (8), pp. e0256350. Date of Electronic Publication: 2021 Aug 19 (Print Publication: 2021).
DOI: 10.1371/journal.pone.0256350
Abstrakt: 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.
Competing Interests: The authors have declared that no competing interests exist.
Databáze: MEDLINE
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