cDNA-AFLP analysis of differentially expressed genes during microspore embryogenesis in non-heading Chinese cabbage

Stress can induce microspores to change their developmental pathway from the gametophytic to the embryogenic pathway. To explore the molecular mechanisms of microspore embryogenesis, complement DNA-amplified fragment length polymorphism was used to isolate the transcript-derived fragments during microspore embryogenesis of the non-heading Brassica campestris L. ssp. chinensis ‘Wuyueman’. With 256 primer combinations screened, a total of 94 transcript-derived fragments were identified, and 15 were successfully sequenced. Based on a BLAST search in the Brassica database, 12 of the 15 sequenced transcript-derived fragments were homologous to genes with annotations; the remaining three transcript-derived fragments did not match any sequences. Transcript-derived fragments with annotations were involved in cell wall formation, hormones, and resistance. Analysis of cis-elements indicated that there were heat shock-related and stress-related cis-elements in the promoter sequences of 12 transcript-derived fragments. TDF1(Bra040720), TDF6(Bra013664), and TDF15(Bra022587) were selected for validation of complement DNA-amplified fragment length polymorphism expression patterns by real-time quantitative PCR. Results confirmed the altered expression patterns of three genes revealed by the complement DNA-amplified fragment length polymorphism. This study provides novel information on the molecular mechanism of microspore embryogenesis in non-heading Chinese cabbage.