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 incellulose biosynthesis. PttCel9A1 from hybrid aspen (Populustremula L. x tremuloides Michx.) has high sequence similarityto KOR1 and we demonstrate here that it complements kor1-1 mutants,indicating that it is a KOR1 ortholog. We investigated the functionof PttCel9A1/KOR1 in Arabidopsis secondary growth using transgeniclines expressing 35S::PttCel9A1 and the KOR1 mutant line irx2-2.The presence of elevated levels of PttCel9A1/KOR1 in secondarywalls of 35S::PttCel9A1 lines was confirmed by in muro visualizationof cellulase activity. Compared with the wild type, 35S::PttCel9A1lines had higher trifluoroacetic acid (TFA)-hydrolyzable glucancontents, similar Updegraff cellulose contents and lower cellulosecrystallinity indices, as determined by 13C solid-state nuclearmagnetic resonance (NMR) spectroscopy. irx2-2 mutants had wild-typeTFA-hydrolyzable glucan contents, but reduced Updegraff cellulosecontents and higher than wild-type cellulose crystallinity indices.The data support the hypothesis that PttCel9A1/KOR1 activityis present in cell walls, where it facilitates cellulose biosynthesisin a way that increases the amount of non-crystalline cellulose.
Place, publisher, year, edition, pages
Oxford Journals , 2009. Vol. 50, no 6, 1099-1115 p.
Aspen, Cellulase, Cellulose, Cell wall, Populus, Wood formation
IdentifiersURN: urn:nbn:se:umu:diva-25864DOI: 10.1093/pcp/pcp062OAI: oai:DiVA.org:umu-25864DiVA: diva2:234448