Proteomic Profiling and Protein-Protein Interaction Network Reveal the Molecular Mechanisms of Susceptibility to Drought Stress in Canola (Brassica napus L.)

Abstract

Drought stress is one of the most important abiotic stresses that plants face frequently in nature. Under drought conditions, many morphological, physiological, and molecular aspects of plants are changed and as a result plants experience a remarkable reduction in growth, yield, and reproduction. To expand our understanding of the molecular basis of the plant response to drought stress, the proteomic profile and protein-protein network of canola (<i>Brassica napus</i> L.) were studied. The focus was to show molecular mechanisms related to canola susceptibility to drought stress. The experiment used a completely randomized design, implemented in a hydroponic system under greenhouse conditions. To impose drought stress, plants were exposed to Hoagland’s solution supplemented with polyethylene glycol (PEG) 6000 for 7 days. The drought stress resulted in 161reproducible protein spots in twodimensional electrophoresis of canola leaves. The t-student test showed 21 differentially abundant proteins (DAP), of which 2 and 19 were up and down accumulated, respectively. Two spots identified as 1-aminocyclopropane-1-carboxylate oxidase and D-2-hydroxyglutarate dehydrogenase showed an increased abundance of 2.11 and 1.77, respectively. The extended protein-protein interaction of differentially abundant proteins and KEGG analysis showed 47 pathways directly and indirectly associated with canola response to drought stress. DAPs with increased abundance were associated with amino acid and signaling processes, whereas DAPs with decreased abundance were mostly connected with pathways responsible for energy production. The results of the study will help to elucidate further the molecular events associated with the susceptibility to drought stress in canola.