Expression data from esd7-1 mutant vs wt (Ler)

We have characterized a mutation affecting the Arabidopsis EARLY IN SHORT DAYS 7 (ESD7) gene encoding the catalytic subunit of the DNA polymerase epsilon (e), AtPOL2A. esd7-1 mutations causes early flowering independently of photoperiod, shortened inflorescence internodes and altered leaf and root development. esd7-1 was a hypomorphic allele whereas KO alleles displayed an embryo-lethal phenotype. The SAM and the RAM in the esd7-1 seedlings were found to exhibit an altered disposition that might correlate with the abnormal expression pattern of SAM and RAM marker genes. esd7-1 showed higher sensitivity to DNA damaging reagents than wild type plants and altered expression of genes involved in DNA repair mechanisms by homologous recombination. Moreover, esd7 early flowering phenotype requires functional FT and SOC1 proteins and might be also related to the mis-regulation of AG and AG-like gene expression found in esd7. Loci involved in the modulation of the chromatin structural dynamics, such as TFL2 and EBS, which negatively regulate FT expression, were found to interact genetically with ESD7, and the carboxy terminus of ESD7 interacted with TFL2 in vitro. Besides, fasciata2 (fas2) mutations suppressed esd7 early flowering phenotype and INCURVATA 2 (ICU2) was found to be epistatic to ESD7. Discrete regions of the chromatin of FT and AG loci were enriched in activating epigenetic marks in the esd7-1 mutant. We concluded that ESD7 might be participating in processes involved in chromatin-mediated cellular memory. We used microarrays to evaluate the genes whose expression was mis-regulated by the esd7-1 mutation Ler and esd7-1 14-d-old seedlings grown under SD photoperiods, were collected 8 h after dawn for RNA extraction and hybridization on Affymetrix microarrays. The experimental design comprised three replicates of each genotype and each replicate corresponded to an RNA extraction of an independent pool of plants.