Quantification of callose deposition. Syncytia of wild type, overexpression lines, and mutant lines at 5, 10, and 15 dpi were stained for callose. The area of syncytia was measured and the number of dots within the area was counted. The data are the mean from 10 syncytia. Data were analysed for significance difference using ANOVA (P < 0.05) and DMRT. Values are means ± SE.