The LInker of Nucleoskeleton and Cytoskeleton (LINC) complex is an evolutionary well-conserved protein bridge connecting the cytoplasmic and nuclear compartments across the nuclear membrane. While recent data support its function in nuclear morphology and meiosis, its implication in chromatin organisation has not been studied in plants. Here 3D imaging methods have been used to investigate nuclear morphology and chromatin organisation in interphase nuclei of the model plant Arabidopsis thaliana, in which heterochromatin cluster in conspicuous chromatin domains called chromocentres. Chromocentres form a repressive chromatin environment contributing to transcriptional silencing of repeated sequences, a general mechanism needed for genome stability. Quantitative measurements of 3D position of chromocentres indicate their close proximity to the nuclear periphery but that their position varies with nuclear volume and can be altered in specific mutants affecting the LINC complex. Finally we propose that the plant LINC complex contributes to proper heterochromatin organisation and positioning at the nuclear periphery, since its alteration is associated with the release of transcriptional silencing as well as decompaction of heterochromatic sequences.
- Received July 4, 2016.
- Accepted December 4, 2016.
- © 2017. Published by The Company of Biologists Ltd