KORRIGAN1 and its Aspen Homolog PttCel9A1 Decrease Cellulose Crystallinity in Arabidopsis Stems
2009 (English)In: Plant and Cell Physiology, ISSN 0032-0781, E-ISSN 1471-9053, Vol. 50, no 6, 1099-1115 p.Article in journal (Refereed) Published
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 C-13 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.
Place, publisher, year, edition, pages
2009. Vol. 50, no 6, 1099-1115 p.
Aspen, Cellulase, Cellulose, Cell wall, Populus, Wood formation, carbohydrate-active enzymes, secondary cell-wall, higher-plants, c-13, nmr, wood formation, biosynthesis, expression, thaliana, endo-1, 4-beta-glucanase, genes
IdentifiersURN: urn:nbn:se:kth:diva-18514DOI: 10.1093/pcp/pcp062ISI: 000266967600009ScopusID: 2-s2.0-67649333159OAI: oai:DiVA.org:kth-18514DiVA: diva2:336561
QC 201005252010-08-052010-08-052011-01-24Bibliographically approved