-
Views
-
Cite
Cite
Junko Takahashi, Ulla J. Rudsander, Mattias Hedenström, Alicja Banasiak, Jesper Harholt, Nicolas Amelot, Peter Immerzeel, Peter Ryden, Satoshi Endo, Farid M. Ibatullin, Harry Brumer, Elena del Campillo, Emma R. Master, Henrik Vibe Scheller, Björn Sundberg, Tuula T. Teeri, Ewa J. Mellerowicz, KORRIGAN1 and its Aspen Homolog PttCel9A1 Decrease Cellulose Crystallinity in Arabidopsis Stems, Plant and Cell Physiology, Volume 50, Issue 6, June 2009, Pages 1099–1115, https://doi.org/10.1093/pcp/pcp062
- Share Icon Share
Abstract
KORRIGAN1 (KOR1) is a membrane-bound cellulase implicated in cellulose biosynthesis. PttCel9A1 from hybrid aspen (Populus tremula L. × tremuloides Michx.) has high sequence similarity to KOR1 and we demonstrate here that it complements kor1-1 mutants, indicating that it is a KOR1 ortholog. We investigated the function of PttCel9A1/KOR1 in Arabidopsis secondary growth using transgenic lines expressing 35S::PttCel9A1 and the KOR1 mutant line irx2-2. The presence of elevated levels of PttCel9A1/KOR1 in secondary walls of 35S::PttCel9A1 lines was confirmed by in muro visualization of cellulase activity. Compared with the wild type, 35S::PttCel9A1 lines had higher trifluoroacetic acid (TFA)-hydrolyzable glucan contents, similar Updegraff cellulose contents and lower cellulose crystallinity indices, as determined by 13C solid-state nuclear magnetic resonance (NMR) spectroscopy. irx2-2 mutants had wild-type TFA-hydrolyzable glucan contents, but reduced Updegraff cellulose contents and higher than wild-type cellulose crystallinity indices. The data support the hypothesis that PttCel9A1/KOR1 activity is present in cell walls, where it facilitates cellulose biosynthesis in a way that increases the amount of non-crystalline cellulose.