Suppression of xylan endotransglycosylase PtxtXyn10A affects cellulose microfibril angle in secondary wall in aspen wood
Teeri, Tuula T
Mellerowicz, Ewa J
Wiley on behalf of the New Phytologist Trust
MetadataShow full item record
Derba-Maceluch, M., Awano, T., Takahashi, J., Lucenius, J., Ratke, C., Kontro, I., Busse-Wicher, M., et al. (2014). Suppression of xylan endotransglycosylase PtxtXyn10A affects cellulose microfibril angle in secondary wall in aspen wood. New Phytologist, 205 666-681. https://doi.org/10.1111/nph.13099
Certain xylanases from family GH10 are highly expressed during secondary wall deposition, but their function is unknown. We carried out functional analyses of the secondary-wall specific PtxtXyn10A in hybrid aspen (Populus tremula L. x tremuloides Michx.). • PtxtXyn10A function was analysed by expression studies, overexpression in Arabidopsis protoplasts and by downregulation in aspen. • PtxtXyn10A overexpression in Arabidopsis protoplasts resulted in increased xylan endotransglycosylation rather than hydrolysis. In aspen, the enzyme was found to be proteolytically processed to a 68 kDa peptide and residing in cell wall. Its downregulation resulted in a corresponding decrease in xylan endotransglycosylase activity and no change in xylanase activity. This did not alter xylan molecular weight or its branching pattern but affected the cellulose- microfibril angle in wood fibres, increased primary growth (stem elongation, leaf formation and enlargement) and reduced the tendency to form tension wood. Transcriptomes of transgenic plants showed downregulation of tension wood related genes and changes in stress-responsive genes. • The data indicate that PtxtXyn10A acts as a xylan endotransglycosylase and its main function is to release tensional stresses arising during secondary wall deposition. Furthermore, they suggest that regulation of stresses in secondary walls plays a vital role in plant development.
Populus, hybrid aspen, secondary cell wall, wood formation, xylanase, xylan endotransglycosylase, cellulose microfibril angle, growth stresses
Formas (including HemiPop and FuncFiber), Swedish Research Council (VR), Swedish Governmental Agency for Innovation Systems (VINNOVA), Swedish Center for Biomimetic Fiber Engineering (funded by the Knut & Alice Wallenberg Foundation and the Foundation for Strategic Research), European projects EDEN (QLK5-CT-2001-00443) and RENEWALL, FORE, Bio4Energy, Wood Ultrastructure Research Centre, SamNordisk Skogsforskning (project no. 107), Japan Society for the Promotion of Science (JSPS KAKENHI Grant Number 24580243) and the Academy of Finland (1127759).
External DOI: https://doi.org/10.1111/nph.13099
This record's URL: https://www.repository.cam.ac.uk/handle/1810/250280