Melanin Promotes Spore Production in the Rice Blast Fungus Magnaporthe oryzae

Frontiers in Microbiology

Xiaohong Liu¹  Huijuan Cao²  Pengyun Huang³  Jianping Lu³  Jing Wang³  Siyi Zhu³  Yan Li³  Qing Wang³  Fu-Cheng Lin⁴ 

[1] Institute of Biotechnology, Zhejiang University, Hangzhou, China;Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China;State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, College of Life Sciences, Zhejiang University, Hangzhou, China;State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China;

关键词: Magnaporthe oryzae;    melanin;    sporulation;    conidia;    transcription factor;    rice blast;   

DOI  :  10.3389/fmicb.2022.843838

来源: DOAJ

【 摘 要 】

The rice blast pathogen, Magnaporthe oryzae, spreads through spores and invades rice through appressoria. Melanin is necessary for an appressorium to penetrate plant cells, but there are many unknown aspects of its role in fungal conidiation. In this study, we confirmed that melanin promotes spore production in M. oryzae, and that this effect is related to the background melanin content of wild-type strains. In the wild-type 70-15 strain with low melanin content of aerial hyphae, increased melanin synthesis promoted sporulation. In contrast, increased melanin synthesis in the wild-type Guy11 strain, which has higher melanin content, did not promote sporulation. The transcription factor Cnf1 (conidial production negative regulatory factor 1), which negatively regulates melanin synthesis, has opposite effects in conidiophore differentiation of Guy11 and 70-15. Deletion of CNF1 did not abolish the defects of Δcos1 and Δhox2 (where COS1/conidiophore stalk-less 1 or HOX2/homeodomain protein 2 was deleted) in conidiation, while increased the conidiation of Δgcc1 and Δgcf3 (where GCC1/growth, conidiation and cell wall regulatory factor 1, or GCF3/growth and conidiation regulatory factor 3 was deleted). Pig1 (pigment of Magnaporthe 1) regulates the melanin synthesis of hyphae but not of conidiophores, spores, or appressoria. Deletion of the same gene in different wild-type strains can lead to different phenotypes, partly because of differences in melanin content between fungal strains. Overall, this study reveals the functional diversity and complexity of melanin in different M. oryzae strains.

【 授权许可】

Unknown