^{Genomics and Molecular Biology}

One of the major abiotic constrains aff ecting plant growth is soil salinity. Despite many years of studying the molecular basis of plant response to high salinity, we still have gaps in our understanding of complex mechanisms underlying plant tolerance to salinity. To advance our knowledge about the early stages of plant cell response to salinity, we carried out a timeseries experiment during the fi rst 100 minutes of high-salt stress. As the most suitable model for performed studies, we chose Arabidopsis T87 cell line, off ering a relative cellular homogeneity comparing to a mixture of cells building the whole seedling or their organs. Our previous results describing nucleosomal response to high salinity, cold and abscisic acid (ABA) showed that Arabidopsis T87 cell line is a very convenient model to analyze stress response at the cellular level. To establish if frequent passages had an impact on T87 cells genome, we characterized a genetic variation in T87 cells. Apart from our previous data demonstrating that phosphorylation of histone H3 (H3S10ph) is a nucleosomal marker of cells standard behavior under stress, we also showed a novel histone modifi cation, H4K16ac to be a valid epigenetic signature of plant stress response. Transcription profi ling of T87 cells led to identifi cation of previously unrecognized genes, strongly activated during fi rst few minutes of salinity stress. Time-series transcriptome analysis during salinity stress followed by Bayesian network modelling recognized a set of hub genes directing the early response of plant cells to salinity stress.