Abstract

Carbon for cellulose biosynthesis is derived from sucrose. Cellulose is synthesized from uridine 5'-diphosphoglucose (UDP-glucose), but the enzyme(s) responsible for the initial sucrose cleavage and the source of UDP-glucose for cellulose biosynthesis in developing wood have not been defined.We investigated the role of CYTOSOLIC INVERTASEs (CINs) during wood formation in hybrid aspen (Populus tremula x tremuloides) and characterized transgenic lines with reduced CIN activity during secondary cell wall biosynthesis.Suppression of CIN activity by 38-55% led to a 9-13% reduction in crystalline cellulose. The changes in cellulose were reflected in reduced diameter of acid-insoluble cellulose microfibrils and increased glucose release from wood upon enzymatic digestion of cellulose. Reduced CIN activity decreased the amount of the cellulose biosynthesis precursor UDPglucose in developing wood, pointing to the likely cause of the cellulose phenotype.The findings suggest that CIN activity has an important role in the cellulose biosynthesis of trees, and indicate that cellulose biosynthesis in wood relies on a quantifiable UDP-glucose pool. The results also introduce a concept of altering cellulose microfibril properties by modifying substrate supply to cellulose biosynthesis.

Keywords

aspen; cell wall; cellulose; invertase; Populus; wood

Published in

New Phytologist
2017, Volume: 214, number: 2, pages: 796-807
Publisher: WILEY

SLU Authors

• Rende, Umut

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Wang, Wei

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Niittylä, Totte

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Botany


Publication identifier

DOI: https://doi.org/10.1111/nph.14392

Permanent link to this page (URI)

https://res.slu.se/id/publ/86356