Skip to main content
SLU publication database (SLUpub)

Research article2009Peer reviewed

KORRIGAN1 and its Aspen Homolog PttCel9A1 Decrease Cellulose Crystallinity in Arabidopsis Stems

Takahashi, Junko; Rudsander, Ulla J.; Hedenstrom, Mattias; Banasiak, Alicja; Harholt, Jesper; Amelot, Nicolas; Immerzeel, Peter; Ryden, Peter; Endo, Satoshi; Ibatullin, Farid M.; Brumer, Harry; del Campillo, Elena; Master, Emma R.; Scheller, Henrik Vibe; Sundberg, Bjorn; Teeri, Tuula T.; Mellerowicz, Ewa J.

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 (13)C 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.

Keywords

Aspen; Cellulase; Cellulose; Cell wall; Populus; Wood formation

Published in

Plant and Cell Physiology
2009, Volume: 50, number: 6, pages: 1099-1115