The dynamics of chromatin changes during barley seed development

Abstract

Cereal grains are among the most important sources of energy for humans and domestic animals, owing to large and nutritious endosperm tissues. We study nuclear organization and chromatin in seeds of cereals using cultivated barley (Hordeum vulgare subsp. vulgare) - a diploid temperate zone model cereal used for both food and feed. Barley has a large genome (2n = 2x = 14, 1C = 5.1 Gbp) with interphase chromosomes organized in Rabl configuration with centromeres and telomeres clustering at opposite nuclear poles. Though considered to be typical for large cereal genomes, observations of Rabl configuration are based mostly on nuclei from meristematic tissues. We explored interphase chromosome organization in different tissues of developing barley grains and will show that Rabl chromosome organization is not a general rule in barley and it diminishes with the increasing nuclear DNA content and seed age. Furthermore, we performed transcriptome profiling of different barley grain tissues that allowed determining roles of different biological processes and also chromatin regulatory pathways during this critical stage of development. In summary, all these facets of our barley chromatin research create a fruitful environment for future functional analyses of nuclear organization and epigenetic regulation of gene expression in this agriculturally important species.