Light-Regulated Gene Expression Patterns During Conidial Formation in Aspergillus oryzae

Area of Science:

• Microbiology
• Molecular Biology
• Mycology

Background:

• The effect of light on conidial formation in *Aspergillus oryzae* is known, but the underlying molecular mechanisms remain unclear.
• Previous studies on light-regulated genes lack comprehensive transcriptional-level explanations for light response patterns.

Purpose of the Study:

• To identify light-regulated genes involved in conidia production and photoreception in *A. oryzae* using RNA sequencing.
• To analyze the impact of light dose on the expression of these identified light-regulated genes via qRT-PCR.

Main Methods:

• RNA sequencing to identify candidate light-regulated genes in *A. oryzae* GDMCC 3.31.
• Quantitative reverse transcription PCR (qRT-PCR) to validate and analyze gene expression patterns under varying light conditions and doses.

Main Results:

• Six genes (*tcsA*, *catA*, *gld1*, *Aowc-1*, *abaA*, and *AofphA*) were identified as light-regulated.
• *abaA* gene expression showed dependence on light spectrum and dose, acting as a red-green light-regulated gene under high light conditions.
• *AofphA*, a phytochrome-like gene, exhibited a biphasic response to red and blue light, indicating a light dose threshold.

Conclusions:

• New light-regulated genes in *A. oryzae* have been identified, expanding the understanding of fungal photoresponse.
• The study highlights the complex regulation of gene expression by light spectrum and dose, particularly for *abaA* and *AofphA*.
• Findings provide novel molecular targets for investigating the photoresponse mechanisms in *A. oryzae*.