Přehled o publikaci

DNA repair is essential for genome stability, and many components of repair pathways are evolutionarily conserved from plants to humans. However, the precise timing of individual repair steps in plant cells remains poorly understood. Following DNA damage, lesions are recognized by protein complexes such as the MRE11-RAD50-NBS1 (MRN) complex, chromatin is remodeled to allow access to repair enzymes, and chromatin structure is subsequently restored. While these steps have been extensively studied using biochemical and transcriptomic methods, real-time visualization in live plant cells has remained challenging. To overcome this, we adapted laser microirradiation, which was originally developed for mammalian systems, for use in plant cells (Nespor-Dadejova et al., 2022). This technique utilizes high-intensity laser pulses from a confocal microscope to induce localized DNA lesions in living cells, enabling real-time fluorescence imaging of repair factor recruitment. Using this approach, we demonstrated that key repair proteins such as PCNA, MRE11, and PARP1 are recruited to damage sites within seconds. Fluorescence recovery after photobleaching (FRAP) further revealed dynamic accumulation patterns, highlighting the rapid kinetics of DNA repair in living plant cells. In our recent work, we extended this method to whole tissues using roots of Arabidopsis thaliana seedlings. This enabled monitoring of DNA repair and recovery in locally damaged cells over extended time frames. Initial findings show dynamic changes at damaged sites, while surrounding undamaged cells maintain their division potential. Our study establishes a platform for in vivo investigation of DNA repair in complex plant tissues, opening new possibilities for understanding how plant cells maintain genome integrity under stress.