Transcriptome analysis of Pyrus pyrifolia leaf buds during transition from endodormancy to ecodormancy

We analyzed the transcriptome of Japanese pear (Pyrus pyrifolia Nakai) 'Kousui' leaf buds during the dormancy transitional phases using a 10K cDNA microarray. Leaf buds were collected in October (deep endodormancy) and February (ecodormancy). Over 1000 genes were differentially expressed (P<0.05, ≥2-fold change). Most of these genes are functionally related to chloroplast or plastids, electron transport or energy pathways, response to stimuli or stress, signal transduction or transcription. Of these genes detected in this study, 76 and 22 were highly induced (≥10-fold change) during endodormancy and ecodormancy phases, respectively. Comparison of selected genes between 'Kousui' and the less-dormant Taiwanese pear 'Hengshanli' (TP-85-119) identified two novel transcription factors (NAC and PRR) whose expression varied concomitantly with the dormancy phase changes. Further studies involving the genes uncovered from this microarray analysis is expected to provide new insights into the molecular events underlying their physiological role in plants including dormancy breaking for stable fruit set. © 2012 Elsevier B.V.