title: Coordinate repression of regulators of embryonic identity by PICKLE during germination in Arabidopsis.
abstract: In angiosperms, germination represents an important developmental transition during which embryonic identity is repressed and vegetative identity emerges. PICKLE (PKL) encodes a CHD3-chromatin-remodeling factor necessary for the repression of expression of LEAFY COTYLEDON1 (LEC1), a central regulator of embryogenesis. A candidate gene approach and microarray analysis identified nine additional genes that exhibit PKL-dependent repression of expression during germination. Transcripts for all three LEAFY COTYLEDON genes, LEC1, LEC2, and FUS3, exhibit PKL-dependent repression, and all three transcripts are elevated more than 100-fold in pkl primary roots that inappropriately express embryonic traits (pickle roots). Three other genes that exhibit PKL-dependent regulation have expression patterns correlated with zygotic or somatic embryogenesis, and one gene encodes a putative Lin-11, Isl-1, MEC-3 (LIM) domain transcriptional regulator that is preferentially expressed in siliques. Genes that exhibit PKL-dependent repression during germination are not necessarily regulated by PKL at other points in development. Our data suggest that PKL selectively regulates a suite of genes during germination to repress embryonic identity. In particular, we propose that PKL acts as a master regulator of the LEAFY COTYLEDON genes, and that joint derepression of these genes is likely to contribute substantially to expression of embryonic identity in pkl seedlings.
authors.affiliation: Department of Biochemistry, Purdue University, West Lafayette, Indiana, IN 47907-2063, USA.
authors.forename: Stanley
authors.initials: S
authors.lastname: Dean Rider
authors.forename: James T
authors.initials: JT
authors.lastname: Henderson
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Jerome
authors.forename: Howard J
authors.initials: HJ
authors.lastname: Edenberg
authors.forename: Jeanne
authors.initials: J
authors.lastname: Romero-Severson
authors.forename: Joe
authors.initials: J
authors.lastname: Ogas
mesh_terms: D017360:Arabidopsis / Q000196:embryology* / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D004265:DNA Helicases; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D018525:Germination; D020411:Oligonucleotide Array Sequence Analysis; D010937:Plant Growth Regulators / Q000378:metabolism*; D018515:Plant Leaves / Q000235:genetics; D018517:Plant Roots / Q000235:genetics; D012639:Seeds / Q000196:embryology / Q000235:genetics* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D010937:Plant Growth Regulators; C402442:AT2G25170 protein, Arabidopsis; D004265:DNA Helicases