Two-dimensional gel electrophoresis-based proteomic analysis of the Medicago truncatula-rust (Uromyces striatus) interaction

A two-dimensional gel electrophoresis (2-DE) based proteomic approach has been used to study the Medicago truncatula-Uromyces striatus interaction. The 2-DE leaf protein profile of three M. truncatula genotypes displaying different phenotypes (susceptible and showing prehaustorial and posthaustorial resistance) in both noninoculated and inoculated plants have been compared. Multivariate statistical analysis identified 63 differential protein spots under the experimental conditions (genotypes/treatments). Variable spots were subjected to tandem mass spectrometry (MS, matrix-assisted laser desorption ionisation time of flight, MALDI-TOF/TOF) analysis to identify their possible functions. A total of 27 proteins were identified using a combination of peptide mass fingerprinting (PMF) and MSMS fragmentation. Most of these observed changes correspond to enzymes involved in photosynthesis, energy metabolic pathways and stress related, whose pattern expression was different in relation to susceptibility/resistance of the genotypes studied. Results obtained in this work suggest that differences observed could be related to efficiency in energy utilisation and the induction of proteins involved in defence mechanism operating during early stages of infection.