title: SNF1-related protein kinases type 2 are involved in plant responses to cadmium stress.
abstract: Cadmium ions are notorious environmental pollutants. To adapt to cadmium-induced deleterious effects plants have developed sophisticated defense mechanisms. However, the signaling pathways underlying the plant response to cadmium are still elusive. Our data demonstrate that SnRK2s (for SNF1-related protein kinase2) are transiently activated during cadmium exposure and are involved in the regulation of plant response to this stress. Analysis of tobacco (Nicotiana tabacum) Osmotic Stress-Activated Protein Kinase activity in tobacco Bright Yellow 2 cells indicates that reactive oxygen species (ROS) and nitric oxide, produced mainly via an l-arginine-dependent process, contribute to the kinase activation in response to cadmium. SnRK2.4 is the closest homolog of tobacco Osmotic Stress-Activated Protein Kinase in Arabidopsis (Arabidopsis thaliana). Comparative analysis of seedling growth of snrk2.4 knockout mutants versus wild-type Arabidopsis suggests that SnRK2.4 is involved in the inhibition of root growth triggered by cadmium; the mutants were more tolerant to the stress. Measurements of the level of three major species of phytochelatins (PCs) in roots of plants exposed to Cd(2+) showed a similar (PC2, PC4) or lower (PC3) concentration in snrk2.4 mutants in comparison to wild-type plants. These results indicate that the enhanced tolerance of the mutants does not result from a difference in the PCs level. Additionally, we have analyzed ROS accumulation in roots subjected to Cd(2+) treatment. Our data show significantly lower Cd(2+)-induced ROS accumulation in the mutants' roots. Concluding, the obtained results indicate that SnRK2s play a role in the regulation of plant tolerance to cadmium, most probably by controlling ROS accumulation triggered by cadmium ions.
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Kulik
authors.forename: Anna
authors.initials: A
authors.lastname: Anielska-Mazur
authors.forename: Maria
authors.initials: M
authors.lastname: Bucholc
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Koen
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Szymanska
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Zmienko
authors.forename: Ewa
authors.initials: E
authors.lastname: Krzywinska
authors.forename: Izabela
authors.initials: I
authors.lastname: Wawer
authors.forename: Fionn
authors.initials: F
authors.lastname: McLoughlin
authors.forename: Dariusz
authors.initials: D
authors.lastname: Ruszkowski
authors.forename: Marek
authors.initials: M
authors.lastname: Figlerowicz
authors.forename: Christa
authors.initials: C
authors.lastname: Testerink
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Sklodowska
authors.forename: David
authors.initials: D
authors.lastname: Wendehenne
authors.forename: Grazyna
authors.initials: G
authors.lastname: Dobrowolska
mesh_terms: D000222:Adaptation, Physiological; D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D002104:Cadmium / Q000378:metabolism*; D019256:Cadmium Chloride / Q000494:pharmacology*; D003593:Cytoplasm / Q000235:genetics / Q000378:metabolism; D004789:Enzyme Activation; D055786:Gene Knockout Techniques; D007501:Iron / Q000378:metabolism; D018613:Microscopy, Confocal; D009154:Mutation; D009569:Nitric Oxide / Q000378:metabolism; D054811:Phytochelatins / Q000378:metabolism; D059828:Plant Cells / Q000187:drug effects / Q000201:enzymology; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D013312:Stress, Physiological; D014026:Nicotiana / Q000187:drug effects / Q000201:enzymology / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D017382:Reactive Oxygen Species; C492978:SnRK2 protein, Arabidopsis; D002104:Cadmium; D009569:Nitric Oxide; D054811:Phytochelatins; D007501:Iron; D017346:Protein Serine-Threonine Kinases; D019256:Cadmium Chloride