title: Additional role of O-acetylserine as a sulfur status-independent regulator during plant growth.
abstract: O-acetylserine (OAS) is one of the most prominent metabolites whose levels are altered upon sulfur starvation. However, its putative role as a signaling molecule in higher plants is controversial. This paper provides further evidence that OAS is a signaling molecule, based on computational analysis of time-series experiments and on studies of transgenic plants conditionally displaying increased OAS levels. Transcripts whose levels correlated with the transient and specific increase in OAS levels observed in leaves of Arabidopsis thaliana plants 5-10 min after transfer to darkness and with diurnal oscillation of the OAS content, showing a characteristic peak during the night, were identified. Induction of a serine-O-acetyltransferase gene (SERAT) in transgenic A. thaliana plants expressing the genes under the control of an inducible promoter resulted in a specific time-dependent increase in OAS levels. Monitoring the transcriptome response at time points at which no changes in sulfur-related metabolites except OAS were observed and correlating this with the light/dark transition and diurnal experiments resulted in identification of six genes whose expression was highly correlated with that of OAS (adenosine-5'-phosphosulfate reductase 3, sulfur-deficiency-induced 1, sulfur-deficiency-induced 2, low-sulfur-induced 1, serine hydroxymethyltransferase 7 and ChaC-like protein). These data suggest that OAS displays a signalling function leading to changes in transcript levels of a specific gene set irrespective of the sulfur status of the plant. Additionally, a role for OAS in a specific part of the sulfate response can be deduced.
authors.affiliation: Max Planck Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, Potsdam-Golm, Germany. hubberten@mpimp-golm.mpg.de
authors.forename: Hans-Michael
authors.initials: HM
authors.lastname: Hubberten
authors.forename: Sebastian
authors.initials: S
authors.lastname: Klie
authors.forename: Camila
authors.initials: C
authors.lastname: Caldana
authors.forename: Thomas
authors.initials: T
authors.lastname: Degenkolbe
authors.forename: Lothar
authors.initials: L
authors.lastname: Willmitzer
authors.forename: Rainer
authors.initials: R
authors.lastname: Hoefgen
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D002940:Circadian Rhythm / Q000502:physiology; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D008027:Light; D020411:Oligonucleotide Array Sequence Analysis; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012694:Serine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000502:physiology; D051050:Serine O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D013455:Sulfur / Q000378:metabolism* / Q000502:physiology; D013997:Time Factors
chemical_list: D029681:Arabidopsis Proteins; D012694:Serine; D013455:Sulfur; D051050:Serine O-Acetyltransferase; C043943:O-acetylserine