Learn More
In a screen to identify novel cellulose deficient mutants, three lines were shown to be allelic and define a novel complementation group, irregular xylem5 (irx5). IRX5 was cloned and encodes a member of the CesA family of cellulose synthase catalytic subunits (AtCesA4). irx5 plants have an identical phenotype to previously described mutations in two other(More)
Forward genetic screens have led to the isolation of several genes involved in secondary cell wall formation. A variety of evidence, however, suggests that the list of genes identified is not exhaustive. To address this problem, microarray data have been generated from tissue undergoing secondary cell wall formation and used to identify genes that exhibit a(More)
The irregular xylem3 (irx3) mutant of Arabidopsis has a severe deficiency in secondary cell wall cellulose deposition that leads to collapsed xylem cells. The irx3 mutation has been mapped to the top arm of chromosome V near the marker nga106. Expressed sequence tag clone 75G11, which exhibits sequence similarity to cellulose synthase, was found to be(More)
Recessive mutations at three loci cause the collapse of mature xylem cells in inflorescence stems of Arabidopsis. These irregular xylem (irx) mutations were identified by screening plants from a mutagenized population by microscopic examination of stem sections. The xylem cell defect was associated with an up to eightfold reduction in the total amount of(More)
A severe lignin mutant, irx4, has been identified in Arabidopsis thaliana as a result of its collapsed xylem phenotype. In contrast to previously described irx mutants, irx4 plants have 50% less lignin than wild-type plants, whilst the cellulose and hemicellulose content remained unchanged. These alterations in the composition of irx4 secondary cell walls(More)
The cortical microtubule (MT) array and its organization is important in defining the growth axes of plant cells. In roots, the MT array exhibits a net-like configuration in the division zone, and a densely-packed transverse alignment in the elongation zone. This transition is essential for anisotropic cell expansion and consequently has been the subject of(More)
Previous studies using co-expression analysis have identified a large number of genes likely to be involved in secondary cell-wall formation. However, the function of very few of these genes is known. We have studied the cell-wall phenotype of irx7, irx8 and irx9, three previously described irregular xylem (irx) mutants, and irx14 and parvus-3, which we now(More)
Xylan, the major hemicellulosic polysaccharide in Arabidopsis secondary cell walls, requires a number of glycosyltransferases (GT) to catalyse formation of the various glycosidic linkages found in the polymer. In this study, we characterized IRX10 and IRX10-like (IRX10-L), two highly homologous genes encoding members of the glycosyltransferase family 47(More)
The irregular xylem 1 (irx1) mutant of Arabidopsis has a severe deficiency in the deposition of cellulose in secondary cell walls, which results in collapsed xylem cells. This mutation has been mapped to a 140-kb region of chromosome 4. A cellulose synthase catalytic subunit was found to be located in this region, and genomic clones containing this gene(More)
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) beta,1-4 endoglucanase (beta,1-4 EGase) gene. Measurement of the total crystalline cellulose in the inflorescence stem indicates that the irx2 mutant contains approximately(More)