Distinct contributions of the peroxisomal import receptors CgPEX5 and CgPEX7 in regulating fungal growth, conidia development, and pathogenicity of the Colletotrichum gloeosporioides

Peroxisomes are single-membrane organelles present in most eukaryotic cells and play important roles in various biological activities. PEX5 and PEX7 are peroxisomal receptors that import matrix proteins containing peroxisomal targeting signals into the peroxisome. However, the specific contributions of CgPEX5 and CgPEX7 in the growth, nutritional utilization, conidial development, and pathogenicity of Colletotrichum gloeosporioides remain to be elucidated. Our results demonstrated that deletion of Cgpex5 or Cgpex7 severely inhibited vegetative growth of C. gloeosporioides. However, compared to the ΔCgpex7 strain, the ΔCgpex5 exhibited reduced capacity for carbon and nitrogen sources utilization, lower conidial production, aberrant conidial morphology and downregulated expression of CgBrlA, CgAbaA and CgWetA in C. gloeosporioides. Transcriptome analysis further indicated that Cgpex5 deletion triggered a reprogramming of crucial metabolic pathways, resulting in altered expression of multiple key metabolism-related genes. In addition, the ΔCgpex5 strain exhibited reduced penetration ability, induced smaller lesions on the host, and led to lower levels of host-derived reactive oxygen species (ROS) during infection compared to the ΔCgpex7 strain. Taken together, our results demonstrate that Cgpex5 gene is essential for growth, nutritional utilization, conidial development, and pathogenesis in C. gloeosporioides, whereas Cgpex7 plays a comparatively minor role. These findings indicated that Cgpex5-mediated peroxisomal import pathway represents a promising target for developing novel fungicidal strategies to control postharvest diseases.