LC-ESI-MS/MS : Liquid chromatography-electrospray ionization-ion-trap tandem mass spectrometry

s 39 40 Herbivorous insects can cause deep cellular changes to plant foliage following infestations depending on feeding 41 behavior. Here, a proteomic study was conducted to investigate green peach aphid (Myzus persicae Sulzer) 42 influence as a polyphagous pest on the defense response of Arabidopsis thaliana (L.) Heynh after aphid colony 43 set up on host plant (3 days). Analysis of about 574 protein spots on 2-DE gel revealed 31 differentially 44 expressed protein spots. Twenty out of 31 differential proteins were selected to be analyzed by mass 45 spectrometry. From 12 out of the 20 analyzed spots, we identified 7 and 9 proteins by MALDI-TOF-MS and LC46 ESI-MS/MS, respectively. Twenty five percents of the analyzed spots contain a couple of proteins. Different 47 metabolic pathways were modulated in Arabidopsis leaves according to aphid feeding: most of them 48 corresponded to carbohydrate, amino acid and energy metabolism, photosynthesis, defense response and 49 translation. This paper has established a survey of early alterations induced in the proteome of Arabidopsis plants 50 by the M. persicae aphids. It provides valuable insights to uncover the complex response of plants to biological 51 stress, particularly with herbivorous insects with sucking feeding behavior. 52 53