Pečinka Group

A longstanding aim of our group is to understand genome organization and functions in plants. We study how DNA is assembled into chromatin and chromosomes and how do the chromatin factors control plant development, stress resistance and genome stability.
Genetic information is stored in cell nucleus on chromosomes. Eukaryotic chromosomes accommodate genes and large amounts of repetitive sequences, some of which are required for telomere, centromere and nucleolar organizer functions. Number of repeats varies greatly among plant species and , in combination with common polyploidization, is responsible for enormous nuclear genome size variation in plants. Furthermore, ratio of genes and repeats often determines overall 3D organization of chromosomes during interphase. Large genomes, such as our model species barley (Hordeum vulgare, 2n=2x=14, ca. 5 Gbp/1C) shows Rabl organization with polar localization of centromeres and telomeres. In contrast, smaller genomes, including our other main model Arabidopsis thaliana (2n=2x=10, ca. 150 Mbp/1C), do not maintain strict clustering of centromeres and have variable positioning of telomeres. In Arabidopsis, centromeres are attached to the nuclear periphery, while telomeres associate with nucleolus. Although described about century ago, molecular mechanisms determining such organizations and their consequences for e.g. nuclear division, DNA damage repair or homolog search remain unknown. We try understanding large scale plant genome organization during normal and DNA damage situations by focusing on the functions of Structural maintenance of chromosomes 5/6 (SMC5/6) complex. SMC5/6 works as intermolecular DNA linker, which ensures plant genome stability by so far unknown mechanism(s). Arabidopsis SMC5/6 mutants are not only DNA damage hypersensitive, but have many other not well understood phenotypes including sensitivity to DNA methylation inhibitors, defects during reproductive development and hyper-immune responses. Roles of SMC5/6 complex in maintaining genome functions in plants with large and Rabl-organized genomes are unknown.

Chromatin properties are determined epigenetically, i.e. by the DNA-interacting proteins and their modifications as well as the regulatory RNAs. Major chromatin states include heterochromatic, which is condensed, repeat-rich and transcriptionally repressed, while euchromatin is open and contains transcriptionally permissive modifications. Chromatin controls transcription in response to developmental and environmental signals and affect plant stress resistance and yield. Our group studies establishment, maintenance and functions of eu-and heterochromatin in plants during cell division and reproduction. This is of important because many plant products (proteins, sugars, oils, fibers) are obtained from plant reproductive tissues.
News
  • 2010-02-27 - Fen won the second place in the poster prize competition at the INDEPTH meeting in Prague. Well done Fen, big congratulations!
  • 2019-02-25-27 - The COST action Impact of Nuclear Domains on Plant Traits (INDEPTH) meeting takes place in Prague. Three days of wonderful talks, discussions and networking around plant nucleus/chromosomes and ways to analyze their structure and functions.
  • 2019-01-07 - Jovanka Vladejić starts her PhD jointly between Dolezel and Pecinka groups. Welcome to IEB Jovanka!
  • 2019-01-01 - Eva Dvorak Tomastikova joins our group after three years in IPK Gatersleben and SLU Uppsala. Welcome back home Eva!
  • 2018-11-27 - Flower or not to flower... Read how do plants decide at the transcriptional level in our collaborative paper with Albani group (Full Text)
  • 2018-10-26 - Homeodomain protein LMI regulates organ proportions by spatial control of endoreduplication. See details in our collaborative paper with Tsiantis group  (Full Text)

Projects

Publications