UBIQUITIN-SPECIFIC PROTEASE 26 is required for seed development and the repression of PHERES1 in Arabidopsis.
The Arabidopsis mutant Atubp26 initiates autonomous endosperm at a frequency of approximately 1% in the absence of fertilization and develops arrested seeds at a frequency of approximately 65% when self-pollinated. These phenotypes are similar to those of the FERTILIZATION INDEPENDENT SEED (FIS) class mutants, mea, fis2, fie, and Atmsi1, which also show development of the central cell into endosperm in the absence of fertilization and arrest of the embryo following fertilization. Atubp26 results from a T-DNA insertion in the UBIQUITIN-SPECIFIC PROTEASE gene AtUBP26, which catalyzes deubiquitination of histone H2B and is required for heterochromatin silencing. The paternal copy of AtUBP26 is able to complement the loss of function of the maternal copy in postfertilization seed development. This contrasts to the fis class mutants where the paternal FIS copy does not rescue aborted seeds. As in the fis class mutants, the Polycomb group (PcG) complex target gene PHERES1 (PHE1) is expressed at higher levels in Atubp26 ovules than in wild type; there is a lower level of H3K27me3 at the PHE1 locus. The phenotypes suggest that AtUBP26 is required for normal seed development and the repression of PHE1.
Luo
Ming
M
CSIRO Plant Industry, Canberra, ACT, Australia. ming.luo@csiro.au
Luo
Ming-Zhu
MZ
Buzas
Diana
D
Finnegan
Jean
J
Helliwell
Chris
C
Dennis
Elizabeth S
ES
Peacock
W J
WJ
Chaudhury
Abed
A
D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics*; D002843:Chromatin / Q000737:chemistry; D047369:Chromatin Immunoprecipitation; D003001:Cloning, Molecular; D010450:Endopeptidases / Q000235:genetics* / Q000502:physiology*; D020868:Gene Silencing; D017343:Genes, Plant; D006570:Heterochromatin / Q000235:genetics; D006657:Histones / Q000235:genetics; D026161:MADS Domain Proteins / Q000235:genetics*; D008957:Models, Genetic; D009154:Mutation; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics; D013997:Time Factors; D064570:Ubiquitin-Specific Proteases
D029681:Arabidopsis Proteins; D002843:Chromatin; D006570:Heterochromatin; D006657:Histones; D026161:MADS Domain Proteins; C475745:PHERES1 protein, Arabidopsis; D010940:Plant Proteins; D010450:Endopeptidases; D064570:Ubiquitin-Specific Proteases