Arabidopsis GT34 family contains five xyloglucan α-1,6-xylosyltransferases.
The Arabidopsis genome includes seven family 34 glycosyltransferase (GT34) encoding genes. XXT1 and XXT2 have previously been shown to encode XyG α-1,6-xylosyltransferases, while knockout mutants of a third, XXT5, exhibit decreased XyG content, suggesting a similar activity. Here, we extend the study to the rest of the Arabidopsis GT34 genes in terms of biochemical activity and their roles in XyG biosynthesis. The enzyme activity of XXTs was investigated using recombinant protein expressed in E. coli. XyG analysis of single and double T-DNA insertion knockouts, together with overexpression of GT34s in selected mutant lines, provided detailed function of each gene. We reveal the activity of the third member of the GT34 gene family (XXT4) that exhibits xylosyltransferase activity. Double mutants for either xxt2 or xxt5 had a large impact on XyG content, structure and size distribution. Overexpression of the remaining member, XXT3, was able to restore XyG epitopes in xxt2, xxt5 and xxt2 xxt5 double knockouts, suggesting that it also encodes a protein with XXT activity. Our work demonstrates that five of the seven Arabidopsis GT34 genes encode XXT enzymes.
Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngam Wong Wan Road, Chatuchak, Bangkok 10900, Thailand.|Center for Advanced Studies in Tropical Natural Resources, Kasetsart University, Ngam Wong Wan, Chatuchak, Bangkok 10900, Thailand.
Supachai
S
Vuttipongchaikij
CNAP, Biology Department, University of York, Heslington, York YO10 5DD, UK.
David
D
Brocklehurst
CNAP, Biology Department, University of York, Heslington, York YO10 5DD, UK.
Clare
C
Steele-King
CNAP, Biology Department, University of York, Heslington, York YO10 5DD, UK.
David A
DA
Ashford
CNAP, Biology Department, University of York, Heslington, York YO10 5DD, UK.
Leonardo D
LD
Gomez
CNAP, Biology Department, University of York, Heslington, York YO10 5DD, UK.
Simon J
SJ
McQueen-Mason
D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002473:Cell Wall / Q000378:metabolism; D002850:Chromatography, Gel; D004789:Enzyme Activation; D000939:Epitopes / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005816:Genetic Complementation Test; D005936:Glucans / Q000378:metabolism; D007150:Immunohistochemistry; D005810:Multigene Family; D010430:Pentosyltransferases / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014990:Xylans / Q000378:metabolism
D029681:Arabidopsis Proteins; D000939:Epitopes; D005936:Glucans; D011993:Recombinant Fusion Proteins; D014990:Xylans; C029353:xyloglucan; D010430:Pentosyltransferases; C029368:xyloglucan xylosyltransferase