Journal Article

ZmXTH1, a new xyloglucan endotransglucosylase/hydrolase in maize, affects cell wall structure and composition in <i>Arabidopsis thaliana</i>

Valeria Genovesi, Silvia Fornalé, Stephen C. Fry, Katia Ruel, Pau Ferrer, Antonio Encina, Fathi-Mohamed Sonbol, Josep Bosch, Pere Puigdomènech, Joan Rigau and David Caparrós-Ruiz

in Journal of Experimental Botany

Published on behalf of Society for Experimental Biology

Volume 59, issue 4, pages 875-889
Published in print March 2008 | ISSN: 0022-0957
Published online March 2008 | e-ISSN: 1460-2431 | DOI: http://dx.doi.org/10.1093/jxb/ern013

More Like This

Show all results sharing this subject:

  • Plant Sciences and Forestry

GO

Show Summary Details

Preview

Xyloglucan endotransglucosylase/hydrolases (XTHs; EC 2.4.1.207 and/or EC 3.2.1.151) are enzymes involved in the modification of cell wall structure by cleaving and, often, also re-joining xyloglucan molecules in primary plant cell walls. Using a pool of antibodies raised against an enriched cell wall protein fraction, a new XTH cDNA in maize, ZmXTH1, has been isolated from a cDNA expression library obtained from the elongation zone of the maize root. The predicted protein has a putative N-terminal signal peptide and possesses the typical domains of this enzyme family, such as a catalytic domain that is homologous to that of Bacillus macerans β-glucanase, a putative N-glycosylation motif, and four cysteine residues in the central and C terminal regions of the ZmXTH1 protein. Phylogenetic analysis of ZmXTH1 reveals that it belongs to subgroup 4, so far only reported from Poaceae monocot species. ZmXTH1 has been expressed in Pichia pastoris (a methylotrophic yeast) and the recombinant enzyme showed xyloglucan endotransglucosylase but not xyloglucan endohydrolase activity, representing the first enzyme belonging to subgroup 4 characterized in maize so far. Expression data indicate that ZmXTH1 is expressed in elongating tissues, modulated by culture conditions, and induced by gibberellins. Transient expression assays in onion cells reveal that ZmXTH1 is directed to the cell wall, although weakly bound. Finally, Arabidopsis thaliana plants expressing ZmXTH1 show slightly increased xyloglucan endohydrolase activity and alterations in the cell wall structure and composition.

Keywords: Cell elongation; cell wall; plant transformation; XEH; XET; XTH; Zea mays

Journal Article.  7871 words.  Illustrated.

Subjects: Plant Sciences and Forestry

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.