title: Pathogen elicitor-induced changes in the maize extracellular matrix proteome.
abstract: The extracellular matrix is a vital compartment in plants with a prominent role in defence against pathogen attack. Using a maize cell suspension culture system and pathogen elicitors, responses to pathogen attack that are localised to the extracellular matrix were examined by a proteomic approach. Elicitor treatment of cell cultures induced a rapid change in the phosphorylation status of extracellular peroxidases, the apparent disappearance of a putative extracellular beta-N-acetylglucosamonidase, and accumulation of a secreted putative xylanase inhibitor protein. Onset of the defence response was attended by an accumulation of glyceraldehyde-3-phosphate dehydrogenase and a fragment of a putative heat shock protein. Several distinct spots of both proteins, which preferentially accumulated in cell wall protein fractions, were identified. These three novel observations, viz. (i) secretion of a new class of putative enzyme inhibitor, (ii) the apparent recruitment of classical cytosolic proteins into the cell wall and (ii) the change in phosphorylation status of extracellular matrix proteins, suggest that the extracellular matrix plays a complex role in defence. We discuss the role of the extracellular matrix in signal modulation during pathogen-induced defence responses.
authors.affiliation: School of Biological and Biomedical Sciences, University of Durham, South Road, Durham DH1 3LE, UK.
authors.forename: Stephen
authors.initials: S
authors.lastname: Chivasa
authors.forename: William J
authors.initials: WJ
authors.lastname: Simon
authors.forename: Xiao-Lan
authors.initials: XL
authors.lastname: Yu
authors.forename: Nasser
authors.initials: N
authors.lastname: Yalpani
authors.forename: Antoni R
authors.initials: AR
authors.lastname: Slabas
mesh_terms: D002473:Cell Wall / Q000737:chemistry / Q000187:drug effects; D002478:Cells, Cultured; D043364:Endo-1,4-beta Xylanases / Q000037:antagonists & inhibitors; D004791:Enzyme Inhibitors / Q000378:metabolism; D005109:Extracellular Matrix / Q000737:chemistry*; D005670:Fusarium / Q000472:pathogenicity; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000096:biosynthesis; D006360:Heat-Shock Proteins / Q000096:biosynthesis; D006861:Hydrogen Peroxide / Q000378:metabolism; D013058:Mass Spectrometry; D010935:Plant Diseases; D010940:Plant Proteins / Q000378:metabolism*; D020543:Proteome / Q000032:analysis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D003313:Zea mays / Q000235:genetics / Q000378:metabolism*
chemical_list: D004791:Enzyme Inhibitors; D006360:Heat-Shock Proteins; D010940:Plant Proteins; D020543:Proteome; D006861:Hydrogen Peroxide; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D043364:Endo-1,4-beta Xylanases