Proteomic comparison of four maize inbred lines with different levels of resistance to Curvularia lunata (Wakker) Boed infection

Protein profiles of leaves in four maize inbred lines with different disease resistance to pathogen Curvularia lunata (Wakker) Boed were studied by two-dimensional electrophoresis (2-DE) and mass spectrometry. Proteins were extracted from the fourth leaf of maize seedlings 24 h after fungal inoculation, and fractionated by polyethylene glycol to precipitate the most abundant leaf protein, Rubisco, before gel separation. Protein profiles from 2-DE showed that total numbers of protein spots were increased in all four inbred lines inoculated with C. lunata CX-3 strain compared with the control. The numbers of changed protein spots in abundance were higher in resistant inbred lines than in susceptible ones, which implied that resistant inbred lines were more sensitive than susceptible ones to pathogen infection. Among proteins identified by MALDI-TOF MS, germin-like protein GLP and translation initiation factor eIF-5A were supposed to play important roles in maize resistance against C. lunata infection.