This project aims at understanding the mechanisms controlling the structure and organization of large chromatin domains and chromosomes in different cell cycle stages and tissues in barley and Arabidopsis. Besides of the wild-type plants, we will obtain/develop mutants in several complexes known to control chromosome organization such as cohesin and condensin. To be able to trace chromatin and chromosome dynamics in vivo in barley, we will develop a series of lines carrying translational fusions of marker proteins indicative of specific chromosome domains (e.g. centromere, telomere) with green or red fluorescent protein (GFP or RFP). These lines and their crosses with mutants will be used for molecular-genetic and cytogenetic analysis. We will also examine the effects of cell phenotypes on plant growth and their yield in control and stress conditions of elevated temperature. Therefore, this project will greatly contribute to understanding the dynamics of chromosomes in plant cell nuclei, reaching the aims of the CA16212 INDEPTH and indicate possible directions in breeding genetically more robust plants.