Proteomic analysis of Allium cepa var. agrogarum L. roots under copper stress

Aims: In the present study, the effects of Cu (2.0 and 8.0 μM) on root growth of Allium cepa var. agrogarum L. were addressed and protein abundance levels were analyzed using the technology of proteomics combined with transcriptomics, in order to go deeper into the understanding of the mechanism of Cu toxicity on plant root systems at the protein level and to provide valuable information for monitoring and forecasting the effects of exposure to Cu in real scenarios conditions.
Methods: Protein extraction; Two-dimensional electrophoresis (2-DE) analysis; Mass spectrometry analysis;
Establishment of the in-house database; Restriction enzyme map of the in-house database and protein
identification.
Results Root growth was dramatically inhibited after 12 h Cu treatment. By establishing an in-house database and using mass spectrometry analysis, 27 differentially abundant proteins were identified. These 27 proteins were involved in multiple biological processes including defensive response, transcription regulation and protein synthesis, cell wall synthesis, cell cycle and DNA replication, and other important functions.
Conclusions: Our results provide new insights at the proteomic level into the Cu-induced responses, defensive responses and toxic effects, and provide new molecular markers of the early events of plant responses to Cu toxicity. Moreover, the establishment of an in-house database provides a big improvement for proteomics
research on non-model plants.