Genes encoding seed storage proteins (SSPs) are specifically and highly expressed during seed maturation. In Arabidopsis, chromatin-based mechanisms involved in the repression of SSPs during germination have been proposed. However, epigenetic regulation involved in repressing SSPs in vegetative tissues of peanut is not well understood. Histone deacetylase (HDAC) is a chromatin-remodelling factor that contributes to transcriptional repression in eukaryotes. To address whether histone deacetylation modification is involved in the repression of SSP genes during germination in peanut, we generated an Ara h 2.02pro : β-glucuronidase (GUS) construct by fusing the 1972 bp Ara h 2.02 promoter of peanut (from -1972 to -1) to the GUS reporter gene and transformed it into wild-type Arabidopsis plants and HDAC mutants. GUS staining revealed that the mutation in HISTONE DEACETYLASE19 (HDA19) resulted in the ectopic expression of peanut SSP gene Ara h 2.02 in seedlings. In addition, Chromatin immunoprecipitation (ChIP) assays showed that the ectopic expression of Ara h 2.02 was accompanied by histone hyperacetylation during germination. These results suggest that histone deacetylation modification may play a vital role in repressing embryonic properties during the peanut vegetative growth.
Keywords: Germination; histone deacetylation; peanut; repressing; seed storage protein.
© 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.