Apoplastic proteome of citrus aurantifolia investigation by two dimensional electrophoresis in response to citrus canker

Citrus canker is a devastating disease that affects most commercial citrus varieties. In the present study changes of apoplastic proteome upon infection were put under scrutiny to define Citrus aurantifolia molecular response. In order to evaluate the changes of extracellular proteome, we employed proteomics to identify apoplastic proteins changed during infection. Citrus plants inoculated with X.citri subsp.citri and inoculated leaves and control leaves (mock inoculated) sampled at 1, 4, 7 days after inoculation in three biological replicates. Apoplastic proteins resolved by 2-DE and differentially expressed spots were identified by MS analysis. In two-dimensional electrophoresis analyses, 63 spots on the gels showed significant changes in abundance at 1,4 and 7 day after inoculation, as compared to non-inoculated plants. Of these 63 proteins, 35 were identified by mass spectrometry analysis using the NCBInr. These proteins were associated with the defense response, photosynthesis, metabolism, and other cellular processes in citrus aurantifolia. It seems that pathogen, by manipulation of host homoeostasis, proliferate and develop disease.