Current address: CNAP, Department of Biology, University of York, Heslington, York YO10 5DD, UK.
The irregular xylem 2 mutant is an allele of korrigan that affects the secondary cell wall of Arabidopsis thaliana
Article first published online: 26 JAN 2004
The Plant Journal
Volume 37, Issue 5, pages 730–740, March 2004
How to Cite
Szyjanowicz, P. M. J., McKinnon, I., Taylor, N. G., Gardiner, J., Jarvis, M. C. and Turner, S. R. (2004), The irregular xylem 2 mutant is an allele of korrigan that affects the secondary cell wall of Arabidopsis thaliana. The Plant Journal, 37: 730–740. doi: 10.1111/j.1365-313X.2003.02000.x
- Issue published online: 26 JAN 2004
- Article first published online: 26 JAN 2004
- Received 22 August 2003; revised 13 November 2003; accepted 26 November 2003.
- cell wall;
The irregular xylem 2 (irx2) mutant of Arabidopsis thaliana exhibits a cellulose deficiency in the secondary cell wall, which is brought about by a point mutation in the KORRIGAN (KOR) β,1-4 endoglucanase (β,1-4 EGase) gene. Measurement of the total crystalline cellulose in the inflorescence stem indicates that the irx2 mutant contains approximately 30% of the level present in the wild type (WT). Fourier–Transform Infra Red (FTIR) analysis, however, indicates that there is no decrease in cellulose in primary cell walls of the cortical and epidermal cells of the stem. KOR expression is correlated with cellulose synthesis and is highly expressed in cells synthesising a secondary cell wall. Co-precipitation experiments, using either an epitope-tagged form of KOR or IRX3 (AtCesA7), suggest that KOR is not an integral part of the cellulose synthase complex. These data are supported by immunolocalisation of KOR that suggests that KOR does not localise to sites of secondary cell wall deposition in the developing xylem. The defect in irx2 plant is consistent with a role for KOR in the later stages of secondary cell wall formation, suggesting a role in processing of the growing microfibrils or release of the cellulose synthase complex.