GSE112225
Cold priming and triggering of Arabidopsis accessions
Plants from temperate regions can be primed by exposure to low, non-freezing temperatures resulting in improved freezing tolerance. Whereas the molecular and metabolic basis of cold priming has been investigated in detail, hardly anything is known about memory of a previous cold event under warm conditions and a following low temperature triggering event. We show that three days of cold priming at 4°C, a seven-day lag phase at 20°C and a triggering treatment of 4°C improved the freezing tolerance of Arabidopsis Col-0 and other accessions compared to plants that were not primed before. Transcripts, metabolites and lipids as possible molecular determinants of this increase in freezing tolerance were investigated in Arabidopsis accessions Col-0 and N14 after priming, memory phase and triggering by Illumina-based RNA-Seq, GC-MS metabolite profiling and UPLC FT-MS-based lipidomics. Comparing primed and triggered with only triggered samples 93 and 128 unique differentially expressed genes could be identified in Col-0 and N14, together with three and six significantly changed lipids and one metabolite in N14. Possible functions of these candidates will be discussed. This work identified for the first time molecular and metabolic changes accompanying cold stress memory and triggering by a second cold stress. Overall design: 6 different conditions were analyzed, control - 28 day old plants (C28), primed (3 days at 4oC) plants (C28P3), primed plants after a memory phase (7 days at 20oC) (C28P3L7), primed and triggered plants (another 3 days at 4oC) (C28P3L7T3) and a developmental control - 35 day old plants (C35) and a primed developmental control (C35P3), 3 independent biological experiments were performed, 2 Arabidopsis accessions were investigated (Col-0 and N14), altogether 36 RNA Seq samples