title: Interplay between calcium signalling and early signalling elements during defence responses to microbe- or damage-associated molecular patterns.
abstract: While diverse microbe- or damage-associated molecular patterns (MAMPs/DAMPs) typically trigger a common set of intracellular signalling events, comparative analysis between the MAMPs flg22 and elf18 revealed MAMP-specific differences in Ca(2+)  signalling, defence gene expression and MAMP-mediated growth arrest in Arabidopsis thaliana. Such MAMP-specific differences are, in part, controlled by BAK1, a kinase associated with several receptors. Whereas defence gene expression and growth inhibition mediated by flg22 were reduced in bak1 mutants, BAK1 had no or minor effects on the same responses elicited by elf18. As the residual Ca(2+)  elevations induced by diverse MAMPs/DAMPs (flg22, elf18 and Pep1) were virtually identical in bak1 mutants, a differential BAK1-mediated signal amplification to attain MAMP/DAMP-specific Ca(2+)  amplitudes in wild-type plants may be hypothesized. Furthermore, abrogation of reactive oxygen species (ROS) accumulation, either in the rbohD mutant or through inhibitor application, led to loss of a second Ca(2+)  peak, demonstrating a feedback effect of ROS on Ca(2+)  signalling. Conversely, mpk3 mutants showed a prolonged accumulation of ROS but this did not significantly impinge on the overall Ca(2+)  response. Thus, fine-tuning of MAMP/DAMP responses involves interplay between diverse signalling elements functioning both up- or downstream of Ca(2+)  signalling.
authors.affiliation: Leibniz Institute of Plant Biochemistry, Stress and Developmental Biology, Weinberg 3, D-06120 Halle, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Ranf
authors.forename: Lennart
authors.initials: L
authors.lastname: Eschen-Lippold
authors.forename: Pascal
authors.initials: P
authors.lastname: Pecher
authors.forename: Justin
authors.initials: J
authors.lastname: Lee
authors.forename: Dierk
authors.initials: D
authors.lastname: Scheel
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000382:microbiology / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D017343:Genes, Plant / Q000235:genetics; D006861:Hydrogen Peroxide / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D057865:Plant Immunity / Q000502:physiology*; D018515:Plant Leaves / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000502:physiology; D018520:Plant Shoots / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000502:physiology; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D011523:Protoplasts; D017382:Reactive Oxygen Species / Q000378:metabolism; D051192:Receptors, Pattern Recognition / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D051192:Receptors, Pattern Recognition; D006861:Hydrogen Peroxide; D011494:Protein Kinases; C463660:BAK1 protein, Arabidopsis; C106294:SERK protein, plant; D017346:Protein Serine-Threonine Kinases; D020928:Mitogen-Activated Protein Kinases; D002118:Calcium