# Comparative proteomic analysis reveals the effects of different light spectra on protein expression in Hericium erinaceus mycelium

## TL;DR

This study uses proteomics to show how different light colors affect protein expression in Hericium erinaceus mycelium.

## Contribution

The study reveals novel insights into how specific light wavelengths modulate protein expression and metabolic pathways in H. erinaceus.

## Key findings

- Blue light treatment resulted in the highest number of uniquely expressed proteins.
- RGB light induced the broadest metabolic and signaling responses in H. erinaceus.
- Different light wavelengths activated distinct biosynthetic and regulatory pathways.

## Abstract

Light represents a major environmental factor influencing the growth, developmental programming, and metabolic regulation of Hericium erinaceus. Different wavelengths differentially affect mycelial development, stress responses, and protein expression, highlighting the complexity of fungal photoregulation. However, the molecular mechanisms and light-responsive regulatory networks in H. erinaceus remain largely unclear, limiting our understanding of how specific light cues shape its proteomic profiles.

A label-free LC-MS/MS quantitative proteomics approach was employed to investigate the global protein expression profiles of H. erinaceus mycelia growing under different light treatments, including blue, green, red, and RGB qualities, compared to control (darkness). The differentially expressed proteins (DEPs) were subsequently annotated and analyzed using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases.

In this study, a total of 4,618 proteins were identified in H. erinaceus, of which 560 were expressed across all experimental conditions. Comparative proteomic analysis under different light treatments revealed 550–677 DEPs per condition, with the blue-light treatment exhibiting the greatest number of uniquely expressed proteins. Light exposure modulated GO-enriched metabolic, biosynthetic, and enzymatic functions in H. erinaceus. RGB induced the broadest responses, while blue, green, and red produced distinct wavelength-specific regulatory patterns. KEGG pathway analysis showed wavelength-dependent proteomic shifts in H. erinaceus, with RGB inducing the strongest metabolic and signaling responses, while blue, green, and red differentially activated energy, biosynthesis, and regulatory pathways. These results support the molecular-mechanistic approach employed and offer valuable insights into protein expression dynamics and regulatory pathways, while also clarifying how different light qualities influence the developmental processes of H. erinaceus.

Infographic describing an experimental workflow to assess the effect of different light spectra on Hericium erinaceus mycelial growth, including experimental setup, mycelia collection, sample preparation for proteomics, LC-MS/MS analysis, protein identification, and bioinformatics for differentially expressed protein analysis.