Nucleolus-associated chromatin domains are maintained under heat stress, despite nucleolar reorganization in Arabidopsis thaliana

Several layers of mechanisms participate in the plant adaptation to heat-stress. For example, the plant metabolism switches from cell growth mode to stress adaptation mode. the biogenesis of ribosomes is one of the most costly pathway in energy. This biogenesis process occurs in the nucleolus, the largest nuclear compartment, whose structure is highly dependent on this pathway. We used a nucleolar marker to track the structure of the nucleolus, and revealed a change in its sub-nucleolar distribution under heat stress. In addition, the nucleolus is implicated in other cellular processes, such as genome organization within the nucleus. However, our analyses of nucleolus-associated chromatin domains under heat stress did not revealed significant differences compare to the control plants, suggesting a lack of connection between two of the main function of the nucleolus: ribosome biogenesis and nuclear organisation.