Distribution of S. indica apoplastic proteins identified by LC-MS/MS analysis from different symbiotic stages (5, 10 and 14 dpi) and in relation to proteins identified in CF of S. indica axenically grown in CM. In total, 102 S. indica proteins were identified in the APF of colonized barley roots. Of these, 33 proteins were present at all three time points. Twenty proteins were unique at 5 days post infection (dpi), 4 at 10 dpi and 21 at 14 dpi. 