title: Four alleles of AtCESA3 form an allelic series with respect to root phenotype in Arabidopsis thaliana.
abstract: Plant cell shape is determined by the orientation of cellulose microfibrils in the primary cell wall. Consequently, mutations that affect genes encoding the enzymes responsible for the synthesis of cellulose, namely, the cellulose synthase catalytic subunits, can alter cell shape substantially, particularly in the roots of affected plants. The multiple response expansion1 (mre1) mutant of Arabidopsis thaliana results from a point mutation in the AtCESA3 gene, which encodes one of the three isoforms of the cellulose synthase catalytic subunit required for synthesis of cellulose in the primary cell wall. Phenotypic comparison of the mre1 mutant with three other alleles (ectopic lignification1-1, ectopic lignification1-2 and constitutive expression of vsp1) showed that these four alleles form an allelic series with respect to their root phenotypes, with mre1 being the weakest allele identified to date. These analyses demonstrated that sucrose affects a significant alteration of cell shape in the roots of these mutants and likely suppresses root cell division in them as well, and that the chemical aminoisobutyric acid can suppress these effects of sucrose. Interestingly, the cell walls in the roots of these four AtCESA3 alleles contain different percentages of cellulose, and these percentages correlate with the lengths of the roots and cortex cells in these roots when grown on media containing high levels of sucrose.
authors.affiliation: Department of Biology, Roanoke College, 221 College Lane, Salem, VA 24153, USA. pysh@roanoke.edu
authors.forename: Leonard
authors.initials: L
authors.lastname: Pysh
authors.forename: Nathan
authors.initials: N
authors.lastname: Alexander
authors.forename: Laura
authors.initials: L
authors.lastname: Swatzyna
authors.forename: Robert
authors.initials: R
authors.lastname: Harbert
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000621:Aminoisobutyric Acids / Q000494:pharmacology; D017360:Arabidopsis / Q000166:cytology / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism; D002482:Cellulose / Q000032:analysis / Q000378:metabolism; D002874:Chromosome Mapping; D005838:Genotype; D005964:Glucosyltransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010641:Phenotype; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D018520:Plant Shoots / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D017354:Point Mutation; D013395:Sucrose / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D000621:Aminoisobutyric Acids; D029681:Arabidopsis Proteins; D007527:Isoenzymes; D013395:Sucrose; D002482:Cellulose; C516179:At5g05170 protein, Arabidopsis; D005964:Glucosyltransferases; C478648:cellulose synthase