Genetic evidence for three unique components in primary cell-wall cellulose synthase complexes in Arabidopsis.
In higher plants, cellulose is synthesized at the plasma membrane by the cellulose synthase (CESA) complex. The catalytic core of the complex is believed to be composed of three types of CESA subunits. Indirect evidence suggests that the complex associated with primary wall cellulose deposition consists of CESA1, -3, and -6 in Arabidopsis thaliana. However, phenotypes associated with mutations in two of these genes, CESA1 and -6, suggest unequal contribution by the different CESAs to overall enzymatic activity of the complex. We present evidence that the primary complex requires three unique types of components, CESA1-, CESA3-, and CESA6-related, for activity. Removal of any of these components results in gametophytic lethality due to pollen defects, demonstrating that primary-wall cellulose synthesis is necessary for pollen development. We also show that the CESA6-related CESAs are partially functionally redundant.
Persson
Staffan
S
Department of Plant Biology, Carnegie Institution, Stanford, CA 94305, USA.
Paredez
Alexander
A
Carroll
Andrew
A
Palsdottir
Hildur
H
Doblin
Monika
M
Poindexter
Patricia
P
Khitrov
Natalie
N
Auer
Manfred
M
Somerville
Chris R
CR
D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics*; D002384:Catalysis; D002473:Cell Wall / Q000201:enzymology*; D002482:Cellulose / Q000737:chemistry; D018506:Gene Expression Regulation, Plant; D005821:Genetic Techniques; D005838:Genotype; D005964:Glucosyltransferases / Q000737:chemistry*; D008027:Light; D008854:Microscopy, Electron; D008957:Models, Genetic; D009154:Mutation; D010641:Phenotype; D011058:Pollen / Q000378:metabolism; D020033:Protein Isoforms
D020033:Protein Isoforms; D002482:Cellulose; D005964:Glucosyltransferases; C478648:cellulose synthase