Article Figures & Data
Figures
- FIG 1
Effect of light on biofilm formation in A. niger. (A) Various amounts of A. niger wild-type spores were inoculated into a 24-well plate, incubated at 30°C in the dark, exposed to light intensity of 1,000 to 4,000 lx for 36 h, and then photographed after CV staining. (B) The corresponding OD570 value in the 24-well plate. The values represent the means and standard deviations of three independent experiments. ***, P < 0.001; **, P < 0.01; *, P < 0.05; two-way ANOVA.
- FIG 2
Appearance and microscopic morphology of A. niger grown in light or darkness. (A) Biofilm on round coverslip after light or dark culture; image was taken by Nova NanoSEM. Scale bar, 40 μm. (B) Biofilm on round coverslip after light or dark culture; image taken by cryo-SEM. Scale bar, 50 μm. (C) A. niger colony growing on PDA solid medium under light or dark conditions. (D) Different colors of A. niger mycelium collected under light or dark conditions (YPD liquid medium). (E) Microscope graphics of A. niger hyphae in YPD liquid medium under light or dark conditions. Scale bar, 200 μm.
- FIG 3
Impact of light sensing on ECM. (A) Immunofluorescence staining images of A. niger biofilm mycelium and polysaccharides taken with a confocal laser-scanning microscope under light or dark conditions. Red indicates PI-stained DNA, and green indicates FITC-ConA-stained exopolysaccharides. Scale bar, 800 μm by 800 μm and 100 μm. (B) The content of β-1,3-glucan, chitin, and α-1,3-glucan. The values represent the means and standard deviations of three independent experiments. ***, P < 0.001; **, P < 0.01; *, P < 0.05; using the Student’s t test.
- FIG 4
Elevated expression of related genes and proteins under light. (A) Expression of genes involved in the synthesis of chitin, GAG, GM, α-1,3-glucan, and β-1,3-glucan. (B) Expression of genes in melanin biosynthesis. (C) Expression of key genes in the MAPK signaling pathway. (D) Western blot results of Hog1 and MpkA protein expression and phosphorylation level under light and dark conditions. (E) Relative abundance of MpkAp and Hog1p and phosphorylated MAPK ratio under light or dark conditions. P-p42/p42 and P-α-Hog1/α-Hog1 represented the ratio of phosphorylated proteins to total proteins, calculated by means. The values represent the means and standard deviations of three independent experiments. ***, P < 0.001; **, P < 0.01; *, P < 0.05; using the Student’s t test.
- FIG 5
Light promotes the production of melanin. (A) Microscope images of A. niger under light or dark conditions. Scale bar, 200 μm and 50 μm. (B) The content of melanin. The values represent the means and standard deviations of three independent experiments. ***, P < 0.001; **, P < 0.01; *, P < 0.05; using the Student’s t test.
- FIG 6
Characterization of hydrophobicity and electrostatic force of A. niger ΔAbr1 and ΔAyg1 strains. (A) Growth of ΔAbr1 and ΔAyg1 strains on normal plates. (B) RNA level of RodA in ΔAbr1 and ΔAyg1 strains. (C) Zeta potential of ΔAbr1 and ΔAyg1 spores. (D) Hydrophobicity detection of ΔAbr1 and ΔAyg1 spores. The values represent the means and standard deviations of three independent experiments. ***, P < 0.001; **, P < 0.01; *, P < 0.05; using the Student’s t test.
- FIG 7
Biofilm formation ability and resistance to cell wall disrupters in A. niger ΔAbr1 and ΔAyg1 strains. (A and B) Image and OD570 of A. niger ΔAbr1 and ΔAyg1 strain CV assay results. (C) resistance of A. niger ΔAbr1 and ΔAyg1 strains to Congo red and Calcofluor white. (D) SEM images of A. niger ΔAbr1 and ΔAyg1 strains. Scale bar, 50 μm. The values represent the means and standard deviations of three independent experiments. ***, P < 0.001; **, P < 0.01; *, P < 0.05; using the Student’s t test.
- FIG 8
Schematic diagram of light signaling-mediated MAPK signaling pathway involved in A. niger biofilm formation. Solid arrow, activation; dotted arrow, indirect effect.
Supplemental Material
FIG S1
Schematic diagram of homologous recombination gene knockout. Download FIG S1, PDF file, 0.2 MB.
Copyright © 2021 Sun et al.
This content is distributed under the terms of the Creative Commons Attribution 4.0 International license.
FIG S2
Schematic diagram of plasmid construction. Download FIG S2, PDF file, 0.1 MB.
Copyright © 2021 Sun et al.
This content is distributed under the terms of the Creative Commons Attribution 4.0 International license.
FIG S3
qRT-PCR verification of the mutant strains and complemented strains. The values are the means and standard deviations of three independent experiments. Download FIG S3, PDF file, 0.3 MB.
Copyright © 2021 Sun et al.
This content is distributed under the terms of the Creative Commons Attribution 4.0 International license.
TABLE S1
Sequence of the oligonucleotide primers used for gene knockout in this study. Download Table S1, PDF file, 0.1 MB.
Copyright © 2021 Sun et al.
This content is distributed under the terms of the Creative Commons Attribution 4.0 International license.
TABLE S2
Sequence of the oligonucleotide primers used for plasmid construction in this study. Download Table S2, PDF file, 0.1 MB.
Copyright © 2021 Sun et al.
This content is distributed under the terms of the Creative Commons Attribution 4.0 International license.
TABLE S3
Genes and primers used for qRT-PCR. Download Table S3, PDF file, 0.1 MB.
Copyright © 2021 Sun et al.
This content is distributed under the terms of the Creative Commons Attribution 4.0 International license.
