Comparative Proteomics Reveals Set of Oxidative Stress and Thaumatin-Like Proteins Associated with Resistance to Late Blight of Tomato

Abstract

Proteomics techniques were used to study the molecular mechanisms involved in the defense of tomato against late blight (Phytophthora infestans). Proteins were extracted from resistant access BGH-2127 and susceptible cultivar "Santa Clara". Leaves of the inoculated and non-inoculated (control) genotypes were collected at 0, 2, and 48 h after inoculation and analyzed by two-dimensional electrophoresis (2-DE), followed by identification with mass spectrometry (MALDI TOF-TOF). A total of 56 differentially abundant proteins were identified, of which 39 were resistant genotypes and 17 were susceptible. These proteins were categorized into functional groups of energy and metabolism, photosynthesis, stress and defense, transcription, other proteins, and as un-characterized ones. For access BGH-2127, oxidative stress proteins (2-cis peroxiedoxin BAS1 and 2-cis peroxiredoxin) and thaumatin-like protein showed increase in the relative abundance at 0 and 48 h of inoculation, respectively, and were therefore considered important for the defense mechanism of this genotype. The expression standards evaluated by real-time PCR differed from the results of the proteomic analysis. The protein-protein interaction networks provided important information on the cellular activities involved in the resistance of BGH-2127 late blight.

Quantitative Proteomics Reveals the Dynamic Regulation of the Tomato Proteome in Response to Phytophthora infestans

“…To date, only a limited number of studies have focused on the tomato proteome in response to P. infestans . A previous proteomics study discovered a total of 56 tomato proteins regulated by P. infestans infection, of which 39 and 17 were found in the resistant and susceptible tomato genotype, respectively [ 15 ]. In the resistant tomato genotype, six proteins associated with immune and defense mechanisms were observed with enhanced abundance after pathogen inoculation, which is comprised of three peroxiredoxins, one PR protein, carboxypeptidase, and predicted R protein.…”

“…However, to date, there has been no comprehensive study reporting the dynamics of the tomato proteome in response to P. infestans . In a previous proteomic study that used two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) for protein identification, only 56 proteins were identified in the proteome of resistant and susceptible tomato cultivars in response to P. infestans infection [ 15 ].…”