title: Two alleles of the AtCesA3 gene in Arabidopsis thaliana display intragenic complementation.
abstract: OBJECTIVE
  Cellulose is the most abundant biomolecule on the planet, yet the mechanism by which it is synthesized by higher plants remains largely unknown. In Arabidopsis thaliana (L.) Heynh, synthesis of cellulose in the primary cell wall requires three different cellulose synthase genes (AtCesA1, AtCesA3, and AtCesA6-related genes [AtCesA2, AtCesA5, and AtCesA6]). The multiple response expansion1 (mre1) mutant contains a hypomorphic AtCesA3 allele that results in significantly shorter, expanded roots. Crosses between mre1 and another allele of AtCesA3 (constitutive expression of VSP1, cev1) yielded an F1 with roots considerably longer and thinner than either parent, suggesting intragenic complementation. The F2 generation resulting from self-crossing these F1 showed three different root phenotypes: roots like mre1, roots like cev1, and roots like the F1.
  
  
  METHODS
  The segregation patterns of the three root phenotypes in multiple F2 and F3 generations were determined. Multiple characteristics of the roots and shoots were analyzed both qualitatively and quantitatively at different developmental stages, both on plates and on soil.
  
  
  RESULTS
  The trans-heterozygous plants differed significantly from the parental mre1 and cev1 lines.
  
  
  CONCLUSIONS
  The two alleles display intragenic complementation. A classic genetic interpretation of these results would suggest that cellulose synthesis requires homo-multimerization of cellulose synthase monomers.
authors.affiliation: Roanoke College, Department of Biology, 221 College Lane, Salem, Virginia 24153 USA pysh@roanoke.edu.
authors.forename: Leonard D
authors.initials: LD
authors.lastname: Pysh
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D005964:Glucosyltransferases / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C516179:At5g05170 protein, Arabidopsis; D005964:Glucosyltransferases
keywords: Arabidopsis thaliana; AtCesA3; Brassicaceae; cell wall; cellulose; cellulose synthase; root