Fig.3-6 Conidial numbers of C100, ΔMareA and OE-MareA in medium with different nitrogen sources
3.2.4 Microscopic Morphological Analysis
In PDA medium, C100 mycelium had septa and a few nuclei. ΔMareA mycelium was slender, with a long distance between septa and few nuclei. OE-MareA mycelium was thicker and had more nuclei, and OE-MareA mycelium exhibited a stronger fluorescence signal. In PDA-Gln medium, both ΔMareA and OE-MareA mycelium were thicker compared to C100, and all three strains showed stronger fluorescence signals. On PDA-(NH4)2SO4 medium, the three strains did not differ significantly, but the fluorescence intensity of C100 was slightly stronger than that of ΔMareA and OE-MareA strains. In PDA-NaNO3 medium, the mycelium of C100 and OE-MareA was thicker than that of ΔMareA . The fluorescence intensity of C100 was the strongest, followed by OE-MareA , while ΔMareA had the weakest intensity. The fluorescence intensity of C100 and OE- MareA in PDA-Urea medium was significantly stronger than that of ΔMareA strain. Overall,the three strains exhibited different morphologies under different culture conditions along with varying levels of fluorescence intensities,with the most significant differences observed in the strain supplemented with NaNO3.This suggests that the MareA gene can influence monascus’ growth and development,and at the same time,the MareA gene utilizes different nitrogen sources differently which subsequently affects monascus’ growth. As shown in Figure 3-7.