In:
Plant Biotechnology Journal, Wiley, Vol. 13, No. 1 ( 2015-01), p. 26-37
Abstract:
The plant GT 43 protein family includes xylosyltransferases that are known to be required for xylan backbone biosynthesis, but have incompletely understood specificities. RT ‐q PCR and histochemical ( GUS ) analyses of expression patterns of GT 43 members in hybrid aspen, reported here, revealed that three clades of the family have markedly differing specificity towards secondary wall‐forming cells (wood and extraxylary fibres). Intriguingly, GT 43 A and B genes (corresponding to the A rabidopsis IRX 9 clade) showed higher specificity for secondary‐walled cells than GT 43 C and D genes ( IRX 14 clade), although both IRX 9 and IRX 14 are required for xylosyltransferase activity. The remaining genes, GT 43 E , F and G ( IRX 9‐ L clade), showed broad expression patterns. Transient transactivation analyses of GT4 3 A and B reporters demonstrated that they are activated by P txt MYB 021 and PNAC 085 (master secondary wall switches), mediated in P txt MYB 021 activation by an AC element. The high observed secondary cell wall specificity of GT 43 B expression prompted tests of the efficiency of its promoter ( p GT 43 B ), relative to the C a MV 35 S ( 35 S ) promoter, for overexpressing a xylan acetyl esterase ( CE 5) or downregulating REDUCED WALL ACETYLATION ( RWA ) family genes and thus engineering wood acetylation. CE5 expression was weaker when driven by p GT 43 B , but it reduced wood acetyl content substantially more efficiently than the 35 S promoter. RNAi silencing of the RWA family, which was ineffective using 35 S , was achieved when using GT 43 B promoter. These results show the utility of the GT 43 B promoter for genetically engineering properties of wood and fibres.
Type of Medium:
Online Resource
ISSN:
1467-7644
,
1467-7652
DOI:
10.1111/pbi.2014.13.issue-1
Language:
English
Publisher:
Wiley
Publication Date:
2015
detail.hit.zdb_id:
2136367-5
SSG:
12
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