Fig. 6

Cytosolic Ca²⁺ levels and the transcription level of the final calcium signaling gene crz1. a Analysis of cytosolic Ca²⁺ levels via the Ca²⁺ fluorescent probe Fluo-3/AM. T. reesei Δ76238 and parental strain RUT-C30 were cultured in MA medium for 96–120 h, using glucose as the sole carbon source. For detection, 50 μM Fluo-3/AM was used, and its intensity was monitored using Automatic Inverted Fluorescence Microscopy. Green fluorescence represents free cytosolic Ca²⁺. b Transcriptional level of the final calcium signaling gene crz1 was evaluated by quantitative real-time PCR (qPCR). T. reesei strains were grown using glucose for 96 or 120 h. The data were normalized to the expression of RUT-C30 over 96 h, with the sar gene used as an endogenous control in all samples. Values are the mean ± SD of the results from three independent experiments. Asterisks indicate significant differences (***p < 0.001, Student’s t test)