Characterization of CaPEX8 in Peroxisome Biogenesis and Pathogenicity of Colletotrichum aenigma

Peroxisomes are ubiquitous organelles that play vital roles in various physiological and biochemical processes, including fatty acid β-oxidation and reactive oxygen species (ROS) metabolism. These organelles have been implicated in the pathogenicity of many plant fungal pathogens. In this study, CaPex8, a homolog of Saccharomyces cerevisiae Pex8, was identified and characterized in Colletotrichum aenigma. CaPEX8 was found to localize to peroxisomes, and its deletion impaired the mutant's ability to utilize fatty acids as a carbon source. Using a green fluorescent protein (GFP) fused to the peroxisomal targeting signal PTS1, the import of peroxisomal matrix proteins was shown to be defective in ΔCapex8 mutants. Additionally, the mutants exhibited elevated conidiation, increased sensitivity to osmotic stress and oxidative stress, and impaired cell wall integrity. Peroxisome biogenesis was also disrupted in the absence of CaPEX8. Taken together, these results demonstrate that CaPex8 is essential for maintaining peroxisomal structure and function, and it significantly influences fungal growth, development, and pathogenicity in C. aenigma.