Biology subjects

Krasylenko, Y.

Publications and source records attributed to Krasylenko, Y..

4 recordsLinked to original sources

bioRxiv2021

Arabidopsis iron superoxide dismutase 1 protects against methyl viologen-induced oxidative stress in a copper-dependent manner

Iron superoxide dismutase 1 (FSD1) was recently characterized as a plastidial, cytoplasmic, and nuclear superoxide dismutase with osmoprotective and antioxidative functions. However, its role in oxidative stress tolerance is not well understood. Here, we characterized the role of FSD1 in response to methyl viologen (MV)-induced oxidative stress in Arabidopsis thaliana. The findings demonstrated that the antioxidative function of FSD1 depends on the availability of Cu2+ in growth media. Prolonged MV exposure led to a decreased accumulation rate of superoxide, higher levels of hydrogen peroxide production, and higher protein carbonylation in the fsd1 mutants and transgenic plants lacking a plastidial pool of FSD1, compared to the wild type. MV led to a rapid increase in FSD1 activity, followed by a decrease. Chloroplastic localization of FSD1 is necessary for these changes. Proteomic analysis showed that the sensitivity of the fsd1 mutants coincided with decreased abundance of ferredoxin and light PSII harvesting complex proteins, with altered levels of signaling proteins. Collectively, the study provides evidence for the conditional antioxidative function of FSD1 and its possible role in signaling.

plant biology↗

bioRxiv2020

Cortical microtubule remodelling during strigolactone- and light-mediated growth inhibition of Arabidopsis hypocotyls

Strigolactones are phytohormones involved in shoot branching and hypocotyl elongation. The latter phenomenon was addressed herein by the exogenous application of a synthetic strigolactone GR24 and an inhibitor of strigolactone biosynthesis TIS108 on hypocotyls of wild type Arabidopsis and a strigolactone signalling mutant max2-1 (more axillary growth 2-1). Owing to the interdependence between light and strigolactone signalling, the present work was extended to seedling cultivation under a standard light/dark regime, or under continuous darkness. Given the essential role of the cortical microtubules in cell elongation, their organization and dynamics were characterized under the conditions of altered strigolactone signalling using fluorescence microscopy methods with different spatiotemporal capacities such as confocal laser scanning microscopy and structured illumination microscopy. It was found that the strigolactone-dependent inhibition of hypocotyl elongation correlated with changes in cortical microtubule organization and dynamics, visualized in living wild type and max2-1 seedlings stably expressing genetically-encoded fluorescent molecular markers for microtubules. Quantitative analysis of microscopic datasets revealed that chemical and/or genetic manipulation of strigolactone signalling affected microtubule remodelling, especially under light conditions. The application of GR24 and TIS108 in dark conditions partially alleviated cytoskeletal rearrangement, suggesting a new mechanistic connection between the cytoskeletal behaviour and the light-dependence of strigolactone signalling. HighlightStrigolactones regulate organization and dynamics of cortical microtubules in hypocotyl cells, which contributes to the light-mediated inhibition of hypocotyl growth in Arabidopsis seedlings.

plant biology↗

bioRxiv2020

FSD1: a plastidial, nuclear and cytoplasmic enzyme relocalizing to the plasma membrane under salinity

Here, we aimed to resolve the developmental expression and subcellular localization of Arabidopsis iron superoxide dismutase FSD1, which belongs to the family of superoxide dismutases (SODs), prominent enzymes decomposing superoxide anion and determining abiotic stress tolerance. We found that fsd1 knockout mutants exhibit reduced lateral root number and that this phenotype was complemented by proFSD1::GFP:FSD1 and proFSD1::FSD1:GFP constructs. Light sheet fluorescence microscopy revealed a temporary accumulation of FSD1-GFP at the site of endosperm rupture during seed germination. In emerged roots, FSD1-GFP showed the highest abundance in cells of the lateral root cap, columella, and endodermis/cortex initials. The largest subcellular pool of FSD1-GFP was localized in the plastid stroma, while it was also located in the nuclei and cytoplasm. FSD1 is crucial for seed germination and salt stress tolerance, which is tightly coupled with FSD1-GFP subcellular relocation to the plasma membrane. FSD1 is most likely involved in superoxide decomposition in the periplasm. This study suggests a new osmoprotective function of SODs in plants.

plant biology↗

bioRxiv2018

Environment and HSP90 modulate MAPK stomatal developmental pathway

Stomatal ontogenesis is a key element of plant adaptation aiming to control photosynthetic efficiency and water management under fluctuating environments 1,2,3. Development of stomata is guided by endogenous and environmental cues and is tightly coupled to overall plant growth 1,2,3. YODA signaling pathway is essential to stomatal lineage specification4,5,6 since it regulates the activities of transcription factors such as SPEECHLESS (SPCH)7,8,9,10. Heat-shock proteins 90 (HSP90s) are evolutionarily conserved molecular chaperones implicated in a broad range of signalling pathways being integrated in interaction networks with client proteins11,12,13,14. Herein, based on genetic, molecular, biochemical, and cell biological evidence we report that heat-stress conditions affect phosphorylation and deactivation of SPCH and modulate stomatal density. We show that genetic and physical interactions between HSP90s and YODA control stomatal patterning, distribution and morphology. We provide solid evidence that HSP90s play a major role in transducing the heat-stress response since they act upstream and downstream of YODA signalling, regulate the activity and nucleocytoplasmic distribution of MAPKs, and the activation of SPCH. Thus, HSPs control the stomatal development both under normal temperature and acute heat-stress conditions. Our results demonstrate that HSP90s couple stomatal formation and patterning to environmental cues providing an adaptive mechanism of heat-stress tolerance response and stomatal formation in Arabidopsis.

plant biology↗