The ectopically parting cells 1-2 (epc1-2) mutant exhibits an exaggerated response to abscisic acid.
The ECTOPICALLY PARTING CELLS 1 (EPC1) gene encodes a putative retaining glycosyltransferase of the GT64 family, and epc1-1 mutant plants have a severely dwarfed phenotype. A new mutant allele of this gene, epc1-2, has been isolated. Reduced cell adhesion that has previously been reported for the epc1-1 mutant was not observed for either the epc1-1 or epc1-2 mutants grown in our conditions, suggesting that EPC1 does not affect cell adhesion but is involved in some other process affecting plant growth and development. It is shown that the epc1-2 mutant exhibits hypersensitivity to the phytohormone abscisic acid in germination and root elongation assays, however it shows an unaltered response to gibberellin, epi-brassinosteroid, auxin, or ethylene. An EPC1:YFP fusion protein is localized to small motile structures within the cytosol that are similar in size and number to the Golgi apparatus. Analysis of cell wall pectins revealed that levels of beta-(1,4)-galactan in the epc1-2 mutant are reduced by 50%, whilst other pectic polysaccharides (homogalacturonan, arabinan, and rhamnogalacturonan II) are unchanged.
Bown
Lindsay
L
Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, UK.
Kusaba
Shinnosuke
S
Goubet
Florence
F
Codrai
Lesley
L
Dale
Aaron G
AG
Zhang
Zhinong
Z
Yu
Xiaolan
X
Morris
Karl
K
Ishii
Tadashi
T
Evered
Carol
C
Dupree
Paul
P
Jackson
Stephen
S
D000040:Abscisic Acid / Q000494:pharmacology*; D000483:Alleles; D017360:Arabidopsis / Q000166:cytology / Q000187:drug effects* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000032:analysis / Q000235:genetics*; D002448:Cell Adhesion / Q000235:genetics; D048429:Cell Size; D002473:Cell Wall / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016695:Glycosyltransferases / Q000032:analysis / Q000235:genetics*; D006056:Golgi Apparatus / Q000378:metabolism; D009154:Mutation; D010368:Pectins / Q000378:metabolism; D010641:Phenotype; D010937:Plant Growth Regulators / Q000494:pharmacology*; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000032:analysis; D015398:Signal Transduction
D029681:Arabidopsis Proteins; D010937:Plant Growth Regulators; D011993:Recombinant Fusion Proteins; D000040:Abscisic Acid; D010368:Pectins; C505815:EPC1 protein, Arabidopsis; D016695:Glycosyltransferases