Biology subjects

Berankova, D.

Publications and source records attributed to Berankova, D..

2 recordsLinked to original sources

bioRxiv2023

Chromatin compaction and spatial organization in rice interphase nuclei

Chromatin organization and its interactions are essential for biological processes such as DNA repair, transcription, and DNA replication. Detailed cytogenetics data on chromatin conformation, and the arrangement and mutual positioning of chromosome territories in interphase nuclei are still widely missing in plants. In this study, level of chromatin condensation in interphase nuclei of rice (Oryza sativa) and the distribution of chromosome territories (CTs) were analyzed. Super-resolution, stimulated emission depletion (STED), microscopy showed different level of chromatin condensation in leaf and root interphase nuclei. 3D immuno-FISH experiments with painting probes specific to chromosomes 9 and 2 were conducted to investigate their spatial distribution in root and leaf nuclei. Six different configurations of chromosome territories, including their complete association, weak association, and complete separation, were observed in root meristematic nuclei, and four configurations were observed in leaf nuclei. The volume of CTs and frequency of their association varied between the tissue types. The frequency of association of CTs specific to chromosome 9, containing NOR region, is also affected by the activity of the 45S rDNA locus. Our data suggested that the arrangement of chromosomes in the nucleus is connected to the position and the size of the nucleolus. HighlightSuper-resolution STED microscopy uncovered detailed chromatin ultrastructure; high level of differences in chromatin condensation and mutual positioning of chromosome territories between and within leaf and root meristem G1 were observed.

plant biology↗

bioRxiv2023

Learning from the expert: studying Salicornia to understand salinity tolerance

Salinity remains a major inhibitor of crop production in irrigated and marginal lands. The identification of genes involved in salinity tolerance has been predominantly limited to model plants and crop species. However, plants naturally adapted to highly saline environments can provide key insights into mechanisms of salinity tolerance. Plants of the genus Salicornia grow in coastal salt marshes, and their growth is even stimulated by NaCl - much can be learnt from them. We generated genome sequences of two Salicornia species and studied the transcriptomic and proteomic responses of Salicornia bigelovii to NaCl. Through the generation of subcellular membrane proteomes, we found that SbiSOS1, a homolog of the well-known SALT-OVERLY-SENSITIVE 1 (SOS1) protein, appears to localize to the tonoplast, where it could be involved in mediating Na+ translocation into the vacuole to prevent toxicity in the cytosol. We identified 11 proteins of interest which, when expressed in yeast, altered salinity tolerance. One of these proteins, SbiSALTY, substantially improves yeast growth on saline media. Structural characterization using NMR showed it to be an intrinsically disordered protein and to localize to the endoplasmic reticulum in planta, where it could interact with ribosomes and RNA, potentially stabilizing or protecting them during salt stress. The study and understanding of the molecular mechanisms providing high salinity tolerance in S. bigelovii is likely to provide significant insights for improving salinity tolerance of crop plants.

plant biology↗