Transcriptional regulation of the CRK/DUF26 group of receptor-like protein kinases by ozone and plant hormones in Arabidopsis.
BACKGROUND
Plant Receptor-like/Pelle kinases (RLK) are a group of conserved signalling components that regulate developmental programs and responses to biotic and abiotic stresses. One of the largest RLK groups is formed by the Domain of Unknown Function 26 (DUF26) RLKs, also called Cysteine-rich Receptor-like Kinases (CRKs), which have been suggested to play important roles in the regulation of pathogen defence and programmed cell death. Despite the vast number of RLKs present in plants, however, only a few of them have been functionally characterized.


RESULTS
We examined the transcriptional regulation of all Arabidopsis CRKs by ozone (O3), high light and pathogen/elicitor treatment - conditions known to induce the production of reactive oxygen species (ROS) in various subcellular compartments. Several CRKs were transcriptionally induced by exposure to O3 but not by light stress. O3 induces an extracellular oxidative burst, whilst light stress leads to ROS production in chloroplasts. Analysis of publicly available microarray data revealed that the transcriptional responses of the CRKs to O3 were very similar to responses to microbes or pathogen-associated molecular patterns (PAMPs). Several mutants altered in hormone biosynthesis or signalling showed changes in basal and O3-induced transcriptional responses.


CONCLUSIONS
Combining expression analysis from multiple treatments with mutants altered in hormone biosynthesis or signalling suggest a model in which O3 and salicylic acid (SA) activate separate signaling pathways that exhibit negative crosstalk. Although O3 is classified as an abiotic stress to plants, transcriptional profiling of CRKs showed strong similarities between the O3 and biotic stress responses.
Wrzaczek
Michael
M
Plant Biology Division, Department of Biosciences, University of Helsinki, Helsinki, Finland.
Brosché
Mikael
M
Salojärvi
Jarkko
J
Kangasjärvi
Saijaliisa
S
Idänheimo
Niina
N
Mersmann
Sophia
S
Robatzek
Silke
S
Karpiński
Stanisław
S
Karpińska
Barbara
B
Kangasjärvi
Jaakko
J
D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D008027:Light; D020411:Oligonucleotide Array Sequence Analysis; D018384:Oxidative Stress; D010126:Ozone / Q000494:pharmacology*; D010937:Plant Growth Regulators / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D018749:RNA, Plant / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism; D016897:Respiratory Burst; D015398:Signal Transduction; D014158:Transcription, Genetic
D029681:Arabidopsis Proteins; D010937:Plant Growth Regulators; D018749:RNA, Plant; D017382:Reactive Oxygen Species; D010126:Ozone; D011494:Protein Kinases