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.
  • 2019-09-17 - Our group outing was a great success! 13 km on the little river through the local protected area. Cool that also our BSc/MSc students joined. And do not worry Klara and Martin, your clothes will dry soon... (foto)
  • 2019-08-30 - Eva won one of the Young Researcher Awards at the Plant Biology CS 2019 meeting in České Budějovice for her talk on epigenetic inhibitors. Big congratulations!
  • 2019-08-20 - ATTENTION! - Post-doc position in chromosome biology (more info)
  • 2019-08-01 - Katka Lahnerova starts her PhD in our group. Welcome Katka!
  • 2019-07-22 - Application of DNA methylation inhibitors can improve microspore embryogenesis in cereals. See more in Anna's recent paper (Full text)
  • 2019-07-01 - Eva co-author on the paper providing characterization of TPX-LIKE proteins in Arabidopsis. Congratulations! (Full text)
  • 2019-06-10-14 - Green for Good V meeting on plant biotechnology takes place in Olomouc with many great speakers (more info)
  • 2019-05-07 - Our future group member Katerina Lahnerova got the Dean's prize for the best master work. That's terrific Katko, keep going!  
  • 2019-05-07: Find our view on "Epigenetic mechanisms of abiotic stress response and memory in plants" (Full text)
  • 2019-04-29 - Our analysis of NSE4 subunits of SMC5/6 complex is published in the Plant Cell (Full text)
  • 2019-04-17 - Pranav awarded as the 2nd best young scientist speaker at the India|EMBO symposium on his project simulating 2050 climate effects on plants. Congratulations Pranav!