Lesion simulating disease 1 and enhanced disease susceptibility 1 differentially regulate UV-C-induced photooxidative stress signalling and programmed cell death in Arabidopsis thaliana.
As obligate photoautotrophs, plants are inevitably exposed to ultraviolet (UV) radiation. Because of stratospheric ozone depletion, UV has become more and more dangerous to the biosphere. Therefore, it is important to understand UV perception and signal transduction in plants. In the present study, we show that lesion simulating disease 1 (LSD1) and enhanced disease susceptibility 1 (EDS1) are antagonistic regulators of UV-C-induced programmed cell death (PCD) in Arabidopsis thaliana. This regulatory dependence is manifested by a complex deregulation of photosynthesis, reactive oxygen species homeostasis, antioxidative enzyme activity and UV-responsive genes expression. We also prove that a UV-C radiation episode triggers apoptotic-like morphological changes within the mesophyll cells. Interestingly, chloroplasts are the first organelles that show features of UV-C-induced damage, which may indicate their primary role in PCD development. Moreover, we show that Arabidopsis Bax inhibitor 1 (AtBI1), which has been described as a negative regulator of plant PCD, is involved in LSD1-dependent cell death in response to UV-C. Our results imply that LSD1 and EDS1 regulate processes extinguishing excessive energy, reactive oxygen species formation and subsequent PCD in response to different stresses related to impaired electron transport.
Department of Plant Genetics, Breeding and Biotechnology, Faculty of Horticulture, Biotechnology and Landscape Architecture; Department of Botany, Faculty of Agriculture and Biology, Warsaw University of Life Sciences (SGGW), 02-776, Warszawa, Poland.
Weronika
W
Wituszyńska
Magdalena
M
Szechyńska-Hebda
Mirosław
M
Sobczak
Anna
A
Rusaczonek
Anna
A
Kozłowska-Makulska
Damian
D
Witoń
Stanisław
S
Karpiński
D000975:Antioxidants / Q000378:metabolism; D017209:Apoptosis / Q000528:radiation effects*; D017360:Arabidopsis / Q000166:cytology* / Q000201:enzymology / Q000528:radiation effects / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004573:Electrolytes / Q000378:metabolism; D005453:Fluorescence; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D017343:Genes, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism; D009154:Mutation; D010084:Oxidation-Reduction / Q000528:radiation effects; D010788:Photosynthesis / Q000528:radiation effects; D018515:Plant Leaves / Q000528:radiation effects / Q000648:ultrastructure; D015398:Signal Transduction / Q000528:radiation effects*; D013312:Stress, Physiological / Q000528:radiation effects*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014466:Ultraviolet Rays
D000975:Antioxidants; D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C118837:EDS1 protein, Arabidopsis; D004573:Electrolytes; C104920:LSD1 protein, Arabidopsis; D014157:Transcription Factors; D002734:Chlorophyll; D006861:Hydrogen Peroxide
abiotic stress; antioxidative enzymes; chlorophyll fluorescence; oxidative stress; transmission electron microscopy