Melanin is recognized as a dark pigment that can protect fungi from the harm of environmental stresses. To investigate what roles of melanin played in the pathogenicity and development of Colletotrichum gloeosporioides, a causal agent of poplar anthracnose, genes encoding a transcription factor CgCmr1 and a polyketide synthase CgPks1 were isolated as the ortholog of Magnaporthe oryzae Pig1 and Pks1 respectively. Deletion of CgCmr1 or CgPks1 resulted in melanin-deficient fungal colony. The ΔCgPks1 mutant showed no melanin accumulation in appressoria, and lack of CgCmr1 also resulted in the delayed and decreased melanization of appressoria. In addition, the turgor pressure of the appressorium was lower in ΔCgPks1 and ΔCgCmr1 than in the wild-type (WT). However, DHN melanin was not a vital factor for virulence in C. gloeosporioides. Moreover, deletion of CgCmr1 and CgPks1 resulted in the hypersensitivity to hydrogen peroxide (H₂O₂) oxidative stress but not to other abiotic stresses. Collectively, these results suggest that CgCmr1 and CgPks1 play an important role in DHN melanin biosynthesis, and melanin was not an essential factor in penetration and pathogenicity in C. gloeosporioides. The data presented in this study will facilitate future evaluations of the melanin biosynthetic pathway and development in filamentous fungi.

黑色素被认为是一种深色色素，可以保护真菌免受环境压力的伤害。为了研究黑色素在胶孢炭疽病（一种杨树炭疽病的病原体）的致病性和发育中的作用， 分别分离出编码转录因子 CgCmr1 和聚酮合酶 CgPks1 的基因作为Magnaporthe oryzae  Pig1 和 Pks1的直系同源物 。CgCmr1 或 CgPks1 的 删除  导致黑色素缺乏的真菌菌落。Δ CgPks1 突变体在附着细胞中没有黑色素积累，并且缺乏 CgCmr1 也导致了附着物的黑色化延迟和减少。此外，ΔCg Pks1 和Δ CgCmr1中附着胞的膨压低 于野生型（WT）。 然而，DHN 黑色素不是 C. gloeosporioides 毒力的重要因素。此外，CgCmr1 和 CgPks1 的缺失  导致对过氧化氢（H ₂ O ₂）氧化应激的超敏反应，但对其他非生物胁迫不敏感。总的来说，这些结果表明 CgCmr1 和 CgPks1 在 DHN 黑色素生物合成中起重要作用，黑色素不是渗透和致病的必要因素。 C. gloeosporioides。本研究中提供的数据将有助于未来对丝状真菌中黑色素生物合成途径和发育的评估。