Proteomic Analysisof Rhizobium favelukesii LPU83 in Responseto Acid Stress

Acid soils constitute a severe problem for leguminous crops mainly through a disturbance in rhizobium–legume interactions. Rhizobium favelukesii—an acid-tolerant rhizobium able to nodulate alfalfa—is highly competitive for nodule occupation under acid conditions but inefficient for biologic nitrogen fixation. In this work, we obtained a general description of the acid-stress response of R. favelukesii LPU83 by means of proteomics by comparing the total proteome profiles in the presence or absence of acid stress by nanoflow ultrahigh-performance liquid chromatography coupled to mass spectrometry. Thus, a total of 336 proteins were identified with a significant differential expression, 136 of which species were significantly overexpressed and 200 underexpressed in acidity. An in silico functional characterization with those respective proteins revealed a complex and pleiotropic response by these rhizobia involving components of oxidative phosphorylation, glutamate metabolism, and peptidoglycan biosynthesis,...