Peanut stunt virus (PSV), which belongs to the Cucumovirus genus, is a pathogen of legumes. Certain PSV strains associated with a
satellite RNA (satRNA) modify the symptoms of infected plants and interfere with plant metabolism. We used PSV-P genomic transcripts (GTs) with and without PSV-P satRNA and a comparative proteomic 2D-DIGE/MS study to assess their effects on Nicotiana benthamiana
infection. When the
proteomes of the PSV-P genomic transcripts-infected (no satRNA present) and mock-inoculated plants were compared 29 differentially regulated
proteins were found. When comparisons were made for plants infected with PSV-P-GT in the presence or absence of satRNA, and for mock-infected plants and those infected with the satRNA-associated PSV-P-GT, 40 and 60 such
proteins, respectively, were found. The presence of satRNA mostly decreased the amounts of the affected host
proteins.
Proteins involved in photosynthesis and carbohydrate metabolism, for example
ferredoxin-NADP-reductase and
malate dehydrogenase, are among the identified affected
proteins in all comparisons.
Proteins involved in
protein synthesis and degradation were also affected. Such
proteins include
chaperonin 60β--whose abundance of the
proteins changed for all comparisons--and
aminopeptidase that is a satRNA- or PSV-P-GT/satRNA-responsive
protein. Additionally, the levels of the stress-related
proteins superoxide dismutase and acidic
endochitinase Q increased in the PSV-P-GT- and PSV-P-GT/satRNA-infected plants. This study appears to be the first report on plant
proteome changes in response to a satRNA presence during
viral infection and, as such, may provide a reference for future studies concerning the influence of satRNAs during
viral infections.