title: Modifications to the Arabidopsis defense proteome occur prior to significant transcriptional change in response to inoculation with Pseudomonas syringae.
abstract: Alterations in the proteome of Arabidopsis (Arabidopsis thaliana) leaves during responses to challenge by Pseudomonas syringae pv tomato DC3000 were analyzed using two-dimensional gel electrophoresis. Protein changes characteristic of the establishment of disease, basal resistance, and resistance-gene-mediated resistance were examined by comparing responses to DC3000, a hrp mutant, and DC3000 expressing avrRpm1, respectively. The abundance of each protein identified was compared with that of selected transcripts obtained from comparable GeneChip experiments. We report changes in three subcellular fractions: total soluble protein, chloroplast enriched, and mitochondria enriched over four time points (1.5-6 h after inoculation). In total, 73 differential spots representing 52 unique proteins were successfully identified. Many of the changes in protein spot density occurred before significant transcriptional reprogramming was evident between treatments. The high proportion of proteins represented by more than one spot indicated that many of the changes to the proteome can be attributed to posttranscriptional modifications. Proteins found to show significant change after bacterial challenge are representative of two main functional groups: defense-related antioxidants and metabolic enzymes. Significant changes to photosystem II and to components of the mitochondrial permeability transition were also identified. Rapid communication between organelles and regulation of primary metabolism through redox-mediated signaling are supported by our data.
authors.affiliation: Department of Agricultural Science, Imperial College London, Wye TN25 5AH, United Kingdom. alex.jones@sainsbury-laboratory.ac.uk
authors.forename: Alexandra M E
authors.initials: AM
authors.lastname: Jones
authors.forename: Vincent
authors.initials: V
authors.lastname: Thomas
authors.forename: Mark H
authors.initials: MH
authors.lastname: Bennett
authors.forename: John
authors.initials: J
authors.lastname: Mansfield
authors.forename: Murray
authors.initials: M
authors.lastname: Grant
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology*; D029681:Arabidopsis Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism; D002853:Chromatography, Liquid; D015180:Electrophoresis, Gel, Two-Dimensional; D018506:Gene Expression Regulation, Plant; D007113:Immunity, Innate / Q000235:genetics; D013058:Mass Spectrometry; D008928:Mitochondria / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D020543:Proteome; D044224:Pseudomonas syringae / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; C502082:AvrRpm1 protein, Pseudomonas syringae; D001426:Bacterial Proteins; D020543:Proteome; D012333:RNA, Messenger