Figure 4: Construction of the yeast strain secreting PvPGIPs and establishment of fungal growth inhibition assay. (a)Western blot analysis of S. cerevisiae engineered to secret PvPGIP1 with anti-HA antibody after three days of growth. PvPGIP1-HA has an expected size at 43kDa. The cell lysate samples indicate the presence of the protein inside the cell. The medium samples indicate the presence of the secreted protein into the yeast medium. The inhibition activity of the secreted PvPGIPs was then tested on a fungal growth inhibition assay. OD readings at 630nm of (b) A. niger and(C) B. cinerea treated with either natamycin (positive control), empty vector yeast (negative control), tPvPGIP2_5-8 secreting yeast, or PvPGIP2 secreting yeast were taken after four days. At 630nm, OD readings are reported to be proportional to the dry weight of fungi (Langvad, 1999). Each bar represents the mean values of six biological replicates, and the err or bars represent the standard deviation of the replicates. The well pictured above each bar is representative sample of the replicates.