title: Proteomic analysis of papaya (Carica papaya L.) displaying typical sticky disease symptoms.
abstract: Papaya (Carica papaya L.) hosts the only described laticifer-infecting virus (Papaya meleira virus, PMeV), which is the causal agent of papaya sticky disease. To understand the systemic effects of PMeV in papaya, we conducted a comprehensive proteomic analysis of leaf samples from healthy and diseased plants grown under field conditions. First, a reference 2-DE map was established for proteins from healthy samples. A total of 486 reproducible spots were identified, and MALDI-TOF-MS/MS data identified 275 proteins accounting for 159 distinct proteins from 231 spots that were annotated. Second, the differential expression of proteins from healthy and diseased leaves was determined through parallel experiments, using 2-DE and DIGE followed by MALDI-TOF-MS/MS and LC-IonTrap-MS/MS, respectively. Conventional 2-DE analysis revealed 75 differentially expressed proteins. Of those, 48 proteins were identified, with 26 being upregulated (U) and 22 downregulated (D). In general, metabolism-related proteins were downregulated, and stress-responsive proteins were upregulated. This expression pattern was corroborated by the results of the DIGE analysis, which identified 79 differentially expressed proteins, with 23 identified (17 U and 6 D). Calreticulin and the proteasome subunits 20S and RPT5a were shown to be upregulated during infection by both 2-DE and DIGE analyses. These data may help shed light on plant responses against stresses and viral infections.
authors.affiliation: Instituto de Bioquímica Médica, Unidade de Espectrometria de Massas e Proteômica, Universidade Federal do Rio de Janeiro e Rede Proteômica do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Silas P
authors.initials: SP
authors.lastname: Rodrigues
authors.forename: José A
authors.initials: JA
authors.lastname: Ventura
authors.forename: Clemente
authors.initials: C
authors.lastname: Aguilar
authors.forename: Ernesto S
authors.initials: ES
authors.lastname: Nakayasu
authors.forename: Igor C
authors.initials: IC
authors.lastname: Almeida
authors.forename: Patricia M B
authors.initials: PM
authors.lastname: Fernandes
authors.forename: Russolina B
authors.initials: RB
authors.lastname: Zingali
mesh_terms: D000595:Amino Acid Sequence; D029441:Carica / Q000033:anatomy & histology / Q000737:chemistry* / Q000821:virology*; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000821:virology*; D018515:Plant Leaves / Q000737:chemistry / Q000821:virology; D010940:Plant Proteins / Q000032:analysis*; D020543:Proteome / Q000032:analysis*; D040901:Proteomics / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
chemical_list: D010940:Plant Proteins; D020543:Proteome