VIB1, a Link between Glucose Signaling and Carbon Catabolite Repression, Is Essential for Plant Cell Wall Degradation by Neurospora crassa
(A) Expression levels of two cellulase genes (cbh-1 and gh5-1) were assessed in the Δ3βG; Δvib-1 strain versus WT, and the Δ3βG and Δvib-1 strains after a shift from sucrose VMM to 0.2% cellobiose versus 2% Avicel. Gene expression levels were measured by relative quantitative-PCR using actin as a control and normalized to expression level when cultures were shifted to VMM with no carbon source. (B) CMCase activity after 24 hrs of growth on 2% cellobiose of the Δ3βG; Δvib-1 strain relative to the WT, and the Δ3βG and Δvib-1 strains. Measured enzyme activity in arbitrary unit (AU) was normalized against to the mycelial biomass of each culture.