title: Members of the RKD transcription factor family induce an egg cell-like gene expression program.
abstract: In contrast to animals, the life cycle of higher plants alternates between a gamete-producing (gametophyte) and a spore-producing (sporophyte) generation. The female gametophyte of angiosperms consists of four distinct cell types, including two gametes, the egg and the central cell, which give rise to embryo and endosperm, respectively. Based on a combined subtractive hybridization and virtual subtraction approach in wheat (Triticum aestivum L.), we have isolated a class of transcription factors not found in animal genomes, the RKD (RWP-RK domain-containing) factors, which share a highly conserved RWP-RK domain. Single-cell RT-PCR revealed that the genes TaRKD1 and TaRKD2 are preferentially expressed in the egg cell of wheat. The Arabidopsis genome contains five RKD genes, at least two of them, AtRKD1 and AtRKD2, are preferentially expressed in the egg cell of Arabidopsis. Ectopic expression of the AtRKD1 and AtRKD2 genes induces cell proliferation and the expression of an egg cell marker. Analyses of RKD-induced proliferating cells exhibit a shift of gene expression towards an egg cell-like transcriptome. Promoters of selected RKD-induced genes were shown to be predominantly active in the egg cell and can be activated by RKD in a transient protoplast expression assay. The data show that egg cell-specific RKD factors control a transcriptional program, which is characteristic for plant egg cells.
authors: Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany.
authors: Dávid
authors: D
authors: Koszegi
authors: Amal J
authors: AJ
authors: Johnston
authors: Twan
authors: T
authors: Rutten
authors: Andreas
authors: A
authors: Czihal
authors: Lothar
authors: L
authors: Altschmied
authors: Jochen
authors: J
authors: Kumlehn
authors: Samuel E J
authors: SE
authors: Wüst
authors: Olga
authors: O
authors: Kirioukhova
authors: Jacqueline
authors: J
authors: Gheyselinck
authors: Ueli
authors: U
authors: Grossniklaus
authors: Helmut
authors: H
authors: Bäumlein
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development; D049109:Cell Proliferation; D018506:Gene Expression Regulation, Plant; D005810:Multigene Family; D016254:Mutagenesis, Insertional; D056771:Ovule / Q000254:growth & development*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development; D011401:Promoter Regions, Genetic; D011523:Protoplasts / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D059467:Transcriptome; D014908:Triticum / Q000235:genetics / Q000254:growth & development*
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors