Sammanfattning

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.

Nyckelord

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

Publicerad i

New Phytologist
2017, Volym: 214, nummer: 2, sidor: 796-807
Utgivare: WILEY

SLU författare

• Rende, Umut

  • Institutionen för skoglig genetik och växtfysiologi, Sveriges lantbruksuniversitet
    

• Wang, Wei

  • Institutionen för skoglig genetik och växtfysiologi, Sveriges lantbruksuniversitet
    

• Niittylä, Totte

  • Institutionen för skoglig genetik och växtfysiologi, Sveriges lantbruksuniversitet
    

UKÄ forskningsämne

Botanik


Publikationens identifierare

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

Permanent länk till denna sida (URI)

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