Arabidopsis XXT5 gene encodes a putative alpha-1,6-xylosyltransferase that is involved in xyloglucan biosynthesis.
The function of a putative xyloglucan xylosyltransferase from Arabidopsis thaliana (At1g74380; XXT5) was studied. The XXT5 gene is expressed in all plant tissues, with higher levels of expression in roots, stems and cauline leaves. A T-DNA insertion in the XXT5 gene generates a readily visible root hair phenotype (root hairs are shorter and form bubble-like extrusions at the tip), and also causes the alteration of the main root cellular morphology. Biochemical characterization of cell wall polysaccharides isolated from xxt5 mutant seedlings demonstrated decreased xyloglucan quantity and reduced glucan backbone substitution with xylosyl residues. Immunohistochemical analyses of xxt5 plants revealed a selective decrease in some xyloglucan epitopes, whereas the distribution patterns of epitopes characteristic for other cell wall polysaccharides remained undisturbed. Transformation of xxt5 plants with a 35S::HA-XXT5 construct resulted in complementation of the morphological, biochemical and immunological phenotypes, restoring xyloglucan content and composition to wild-type levels. These data provide evidence that XXT5 is a xyloglucan alpha-1,6-xylosyltransferase, and functions in the biosynthesis of xyloglucan.
Zabotina
Olga A
OA
Institute for Integrative Genome Biology, Center for Plant Cell Biology and Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA.
van de Ven
Wilhelmina T G
WT
Freshour
Glenn
G
Drakakaki
Georgia
G
Cavalier
David
D
Mouille
Gregory
G
Hahn
Michael G
MG
Keegstra
Kenneth
K
Raikhel
Natasha V
NV
D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002473:Cell Wall / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004269:DNA, Bacterial / Q000235:genetics; D017343:Genes, Plant; D005816:Genetic Complementation Test; D005936:Glucans / Q000096:biosynthesis*; D013058:Mass Spectrometry; D016254:Mutagenesis, Insertional; D009154:Mutation; D010430:Pentosyltransferases / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D018749:RNA, Plant / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014990:Xylans / Q000096:biosynthesis*
D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D005936:Glucans; D018749:RNA, Plant; C036483:T-DNA; D014990:Xylans; C029353:xyloglucan; D010430:Pentosyltransferases; C029368:xyloglucan xylosyltransferase