title: Sultr4;1 mutant seeds of Arabidopsis have an enhanced sulphate content and modified proteome suggesting metabolic adaptations to altered sulphate compartmentalization.
abstract: BACKGROUND
  Sulphur is an essential macronutrient needed for the synthesis of many cellular components. Sulphur containing amino acids and stress response-related compounds, such as glutathione, are derived from reduction of root-absorbed sulphate. Sulphate distribution in cell compartments necessitates specific transport systems. The low-affinity sulphate transporters SULTR4;1 and SULTR4;2 have been localized to the vacuolar membrane, where they may facilitate sulphate efflux from the vacuole.
  
  
  RESULTS
  In the present study, we demonstrated that the Sultr4;1 gene is expressed in developing Arabidopsis seeds to a level over 10-fold higher than the Sultr4;2 gene. A characterization of dry mature seeds from a Sultr4;1 T-DNA mutant revealed a higher sulphate content, implying a function for this transporter in developing seeds. A fine dissection of the Sultr4;1 seed proteome identified 29 spots whose abundance varied compared to wild-type. Specific metabolic features characteristic of an adaptive response were revealed, such as an up-accumulation of various proteins involved in sugar metabolism and in detoxification processes.
  
  
  CONCLUSIONS
  This study revealed a role for SULTR4;1 in determining sulphate content of mature Arabidopsis seeds. Moreover, the adaptive response of sultr4;1 mutant seeds as revealed by proteomics suggests a function of SULTR4;1 in redox homeostasis, a mechanism that has to be tightly controlled during development of orthodox seeds.
authors.affiliation: UMR102 Genetics and Ecophysiology of Grain legumes, INRA, F-21000 Dijon, France. helene.zuber@dijon.inra.fr
authors.forename: Hélène
authors.initials: H
authors.lastname: Zuber
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Davidian
authors.forename: Markus
authors.initials: M
authors.lastname: Wirtz
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Hell
authors.forename: Maya
authors.initials: M
authors.lastname: Belghazi
authors.forename: Richard
authors.initials: R
authors.lastname: Thompson
authors.forename: Karine
authors.initials: K
authors.lastname: Gallardo
mesh_terms: D000222:Adaptation, Physiological; D027321:Anion Transport Proteins / Q000235:genetics* / Q000378:metabolism; D017360:Arabidopsis / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D002451:Cell Compartmentation; D004269:DNA, Bacterial / Q000235:genetics; D015180:Electrophoresis, Gel, Two-Dimensional; D035264:Flowers / Q000502:physiology; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D005978:Glutathione / Q000378:metabolism; D016254:Mutagenesis, Insertional / Q000235:genetics; D009154:Mutation / Q000235:genetics*; D009584:Nitrogen / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism; D020543:Proteome / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012639:Seeds / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism*
chemical_list: D027321:Anion Transport Proteins; D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D020543:Proteome; D012333:RNA, Messenger; D013431:Sulfates; C550543:Sultr4;1 protein, Arabidopsis; C036483:T-DNA; D002244:Carbon; D005978:Glutathione; D009584:Nitrogen