1/ Key to the flora of the Czech Republic

The plant diversity of the Czech Republic is constantly changing due to climate change and direct human activities. Our knowledge on plants improves, mainly due to the applications of molecular methods in systematics and the considerable progress in taxonomy and floristics. All this progress is reflected in this new identification guide and inventory of the Czech plant diversity (>3700 species), which is an essential tool for field botanists, students, teachers, ecologists and conservationists.

Cooperating institutions: Masaryk University in Brno, University of South Bohemia in České Budějovice, Jan Evangelista Purkyně University in Ústí nad Labem

• Kaplan Z., Danihelka J., Chrtek J. jun., Kirschner J., Kubát K., Štech M. & Štěpánek J. (eds). Klíč ke květeně České republiky. Ed. 2. Academia, Praha, 2019.

2/ Genome characteristics of orchids and their importance in the evolution of this group of plants with the greatest species diversity

Diversity in genome size and GC content posses substantial adaptive potential in orchids and is tightly linked to the ability to replicate DNA partially throughout the cell differentiation, to particular life-history traits, and climatic conditions. It means, for example, differential evolution for geophytes of temperate climatic zones or lianas of tropical regions. Namely GC content exhibits unparallel diversity and orchids set new limits for angiosperms as well as for eukaryotes.

Calypso bulbosa var. occidentalis, an orchid geophyte facing extremely short vegetation periods and cold winters, has set a new lowest limit for the estimated GC content of plants (23.9%). Photo Jan Ponert

Cooperating institution: University of South Bohemia in České Budějovice

• Trávníček P., Čertner M., Ponert J., Chumová Z., Jersáková, J., Suda, J. Diversity in genome size and GC content shows adaptive potential in orchids and is closely linked to partial endoreplication, plant life-history traits and climatic conditions. <em>New Phytologist. </em> 2019, 224(4), 1642-1656. ISSN 0028-646X doi: 10.1111/nph.15996

3/ Toxicity of graphene oxide against algae and cyanobacteria: Nanoblade-morphology-induced mechanical injury and selfprotection mechanism

Graphene and its derivatives have attracted particular interest because of their remarkable properties. We compared the toxicity of differently oxidized graphene oxide systems towards the green alga and the cyanobacterium. We present the first evidence that algae can dynamically protect themselves against the toxic effects of GOs by secreting extracellular proteins and carbohydrates around the cells.

SEM images of algal cells after 24 h incubation with 200 µg/ml of HO-GO. B) Detailed image of severely damaged algal cell with HO-GO. White arrows show HO-GO sheets, red arrow shows clear cut on cell surface.

Cooperating institution: Palacký University Olomouc

• Malina T.,  Maršálková E., Holá, K.; Tuček, J.; Scheibe, M.; Zbořil, R.; Maršálek B.: Toxicity of graphene oxide against algae and cyanobacteria: Nanoblade-morphology-induced mechanical injury and self-protection mechanism, 2019, Carbon 155, 386-396, doi: 10.1016/j.carbon.2019.08.086.