Research Information System
Plant Molecular Biology Reporter, vol.43, no.3, pp.1566-1575, 2025 (SCI-Expanded)
The DNA in eukaryotic cells is packed into chromatin along with histone proteins. The addition and removal of histone proteins from chromatin are facilitated by histone chaperones. ASF1 is a highly conserved histone chaperone associated with H3.1 and H3.3 histone variants. Its absence in Arabidopsis thaliana results in the redistribution of H3 histone variants in chromatin. Telomeres are complexes of short repetitive sequences and proteins located at the ends of eukaryotic chromosomes, and A. thaliana telomeres are rich in H3.3. Therefore, it is conceivable that ASF1 may play an active role on Arabidopsis telomeres. In this study, the changes in Arabidopsis thaliana telomere parameters in response to ASF1 absence were investigated. The expression profiles of the telomerase enzyme subunit TERT and telomere-associated proteins CTC1, POT1a, TRB1, and BT2 were analyzed using qPCR. Relative telomere lengths of single and double mutants of ASF1a and ASF1b homologs in Arabidopsis callus cultures were measured by Monochrome Multiplex qPCR. It was observed that the mutation in ASF1 homologs led to telomere shortening and alterations in telomere-related gene expressions in Arabidopsis calli. The finding that decreased or unchanged TERT expression does not prevent telomere shortening suggests that telomeres may be shortened independently of telomerase in the absence of ASF1.