Deciphering priming-induced improvement of rapeseed (Brassica napus L.) germination through an integrated transcriptomic and proteomic approach

•Changes of transcriptome and proteome during seed priming and germination are shown.•Relationship between mRNA and protein profile is discussed.•Soaking, drying and germination of primed seeds trigger distinct specific pathways.•Primed seed transcriptome and proteome exhibits footprints of late maturation program.•Progress toward germination is due to increase in protein synthesis potential, PTMs, proteolysis. Rape seeds primed with −1.2MPa polyethylene glycol 6000 showed improved germination performance. To better understand the beneficial effect of osmopriming on seed germination, a global expression profiling method was used to compare, for the first time, transcriptomic and proteomic data for osmoprimed seeds at the crucial phases of priming procedure (soaking, drying), whole priming process and subsequent germination. Brassica napus was used here as a model to dissect the process of osmopriming into its essential components. A total number of 952 genes and 75 proteins were affected during the main phases of priming and post-priming germination. Transcription was not coordinately associated with translation resulting in a limited correspondence between mRNAs level and protein abundance. Soaking, drying and final germination of primed seeds triggered distinct specific pathways since only a minority of genes and proteins were involved in all phases of osmopriming while a vast majority was involved in only one single phase. A particular attention was paid to genes and proteins involved in the transcription, translation, reserve mobilization, water uptake, cell cycle and oxidative stress processes.