Auxins production
The auxins production in the presence of 50% v/v Trichodermaspp. was quantified using the Salkowski reagent . Bacterial cultures (5 ml) at initial OD600 0.1 were grown at 30°C overnight in TY medium supplemented with 1.25 mM L-tryptophan and 50% v/v fungal spent medium. After 24 h, cell cultures were centrifuged at 10,000 rpm for 10 minutes. The culture supernatants and the Salkowski reagent (distilled water 300 ml, 95-97% H2SO4180 ml, 0.5 M FeCl3 9 ml) were mixed (1:4 ratio) and incubated in the dark for 30 min at room temperature. The absorbance was estimated at 530 nm with a spectrophotometer. The auxins concentration in cultures was estimated based on the IAA standard curve. Four biological replicates (independent cultures) were performed. Production inhibition index was calculated as: 1- OD530trt/OD530 ctr where OD represents the values of optical density at 530 nm for treated (trt) and control (ctr) samples.