PCC1: a merging point for pathogen defence and circadian signalling in Arabidopsis.
Using a cDNA-array we identified expressed sequence tag 163B24T7 as rapidly up-regulated in Arabidopsis thaliana (L.) Heynh. after pathogen exposure. Detailed expression analysis revealed that the corresponding gene is up-regulated not only after exposure to avirulent Pseudomonas syringae pv. tomato but also to virulent strains. This up-regulation is dependent on functional salicylic acid defence-signalling pathways. Moreover, we found the gene was circadian-regulated, showing peaks of expression at the end of the day. Using plants overexpressing the clock component CCA1, we showed that the PCC1 gene is regulated by the inner clock of Arabidopsis. Accordingly, we named the gene PCC1, for pathogen and circadian controlled. PCC1 is a member of a novel family of six small polypeptides in Arabidopsis. A functional role for PCC1 in plant defence was demonstrated since plants overexpressing PCC1 are resistant against normally virulent oomycetes. Thus, PCC1 demonstrates a potential interrelationship between pathogen and circadian signalling pathways.
Sauerbrunn
Nicolas
N
Institut Bio III (Pflanzenphysiologie), RWTH Aachen, 52056 Aachen, Germany.
Schlaich
Nikolaus L
NL
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000502:physiology*; D001483:Base Sequence; D002940:Circadian Rhythm / Q000502:physiology*; D003001:Cloning, Molecular; D017124:Conserved Sequence; D017931:DNA Primers; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000382:microbiology; D044224:Pseudomonas syringae / Q000472:pathogenicity*; D012333:RNA, Messenger / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000502:physiology*; D014158:Transcription, Genetic
D029681:Arabidopsis Proteins; D017931:DNA Primers; C484238:PCC1 protein, Arabidopsis; D012333:RNA, Messenger