title: Extracellular matrix-associated proteome changes during non-host resistance in citrus-Xanthomonas interactions.
abstract: Non-host resistance (NHR) is a most durable broad-spectrum resistance employed by the plants to restrict majority of pathogens. Plant extracellular matrix (ECM) is a critical defense barrier. Understanding ECM responses during interaction with non-host pathogen will provide insights into molecular events of NHR. In this study, the ECM-associated proteome was compared during interaction of citrus with pathogen Xanthomonas axonopodis pv. citri (Xac) and non-host pathogen Xanthomonas oryzae pv. oryzae (Xoo) at 8, 16, 24 and 48 h post inoculation. Comprehensive analysis of ECM-associated proteins was performed by extracting wall-bound and soluble ECM components using both destructive and non-destructive procedures. A total of 53 proteins was differentially expressed in citrus-Xanthomonas host and non-host interaction, out of which 44 were identified by mass spectrometry. The differentially expressed proteins were related to (1) defense-response (5 pathogenesis-related proteins, 3 miraculin-like proteins (MIR, MIR1 and MIR2) and 2 proteases); (2) enzymes of reactive oxygen species (ROS) metabolism [Cu/Zn superoxide dismutase (SOD), Fe-SOD, ascorbate peroxidase and 2-cysteine-peroxiredoxin]; (3) signaling (lectin, curculin-like lectin and concanavalin A-like lectin kinase); and (4) cell-wall modification (α-xylosidase, glucan 1, 3 β-glucosidase, xyloglucan endotransglucosylase/hydrolase). The decrease in ascorbate peroxidase and cysteine-peroxiredoxin could be involved in maintenance of ROS levels. Increase in defense, cell-wall remodeling and signaling proteins in citrus-Xoo interaction suggests an active involvement of ECM in execution of NHR. Partially compromised NHR in citrus against Xoo, upon Brefeldin A pre-treatment supported the role of non-classical secretory proteins in this phenomenon.
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500 046, Andhra Pradesh, India.
authors.forename: Tirupaati
authors.initials: T
authors.lastname: Swaroopa Rani
authors.forename: Appa Rao
authors.initials: AR
authors.lastname: Podile
mesh_terms: D000595:Amino Acid Sequence; D002957:Citrus / Q000378:metabolism* / Q000382:microbiology; D016000:Cluster Analysis; D060467:Disease Resistance; D015180:Electrophoresis, Gel, Two-Dimensional; D005109:Extracellular Matrix / Q000378:metabolism* / Q000382:microbiology; D054884:Host-Pathogen Interactions; D015151:Immunoblotting; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000378:metabolism / Q000382:microbiology; D010940:Plant Proteins / Q000145:classification / Q000378:metabolism*; D020543:Proteome / Q000145:classification / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014974:Xanthomonas / Q000254:growth & development* / Q000502:physiology
chemical_list: D010940:Plant Proteins; D020543:Proteome