title: Transcriptional profiling of imbibed Brassica napus seed.
abstract: Using an Arabidopsis microarray, we compared gene expression between germinating Brassica napus seeds and seeds in which germination was inhibited either by polyethylene glycol (PEG) or by the abscisic acid (ABA) analog PBI429, which produces stronger and longer lasting ABA-like effects. A total of 40 genes were induced relative to the germinating control by both treatments. Conspicuous among these were genes associated with late seed development. We identified 36 genes that were downregulated by both PEG and PBI429. Functions of these genes included carbohydrate metabolism, cell wall-related processes, detoxification of reactive oxygen, and triacylglycerol breakdown. The PBI429 treatment produced an increase in endogenous ABA and increased ABA catabolism. However, PEG treatment did not result in similar effects. The transcription factor ABI5 was consistently upregulated by both treatments and PKL was downregulated. These results suggest a greater importance of ABA signaling and reduced importance of GA signaling in nongerminating seeds.
authors.affiliation: Plant Biotechnology Institute, National Research Council of Canada, 110 Gymnasium Place, Saskatoon, Canada S7N 0W9.
authors.forename: Fengling
authors.initials: F
authors.lastname: Li
authors.forename: Xianzhong
authors.initials: X
authors.lastname: Wu
authors.forename: Edward
authors.initials: E
authors.lastname: Tsang
authors.forename: Adrian J
authors.initials: AJ
authors.lastname: Cutler
mesh_terms: D000040:Abscisic Acid / Q000633:toxicity; D015152:Blotting, Northern; D029688:Brassica napus / Q000235:genetics*; D017931:DNA Primers; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D017343:Genes, Plant / Q000235:genetics*; D018525:Germination / Q000187:drug effects; D046228:Microarray Analysis; D011092:Polyethylene Glycols / Q000633:toxicity; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012639:Seeds / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013997:Time Factors
chemical_list: D017931:DNA Primers; D011092:Polyethylene Glycols; D000040:Abscisic Acid