EN
A cDNA-amplified fragment length polymorphism (cDNA-AFLP) approach was used to analyze the spatio-temporal transcript profilings in cotyledons, radicle and hypocotyl of Brassica napus (B. napus) seed during different stages of germination. In total, 75 differentially expressed transcript-derived fragments (TDFs) in cotyledons, 145 in radicle and 145 in hypocotyl were sequenced. Base on BLAST analyses, 37 TDFs in cotyledons, 66 in radicle and 72 in hypocotyl were homologous to genes with known function in the database, respectively. The above known transcripts (175 in total) in three tissues were classified into categories based on their biochemical functions. These genes belong to 14 different functional categories and most of them correspond to metabolic processes, followed by transcription, signal transduction, translation and transport. However, many classes were expressed specifically, including regulation of metabolism and protein function genes in cotyledons, cell rescue and defense genes in radicle, signal transduction genes in hypocotyl. Besides, the expression of eleven identified genes was verified by semi-quantitative reverse transcription polymerase chain reaction in different tissues. The results showed differential gene expression at various germination stages and characteristic gene expression in different seed tissues. Analysis of gene expression profile of B. napus seed is useful for further investigating the seed germination mechanism.