Biosynthesis of conidial and sclerotial pigments in Aspergillus species

Authors: Chang, Perng Kuang; Cary, Jeffrey; Lebar, Matthew

Submitted to: Applied Microbiology and Biotechnology
Publication Type: Review Article
Publication Acceptance Date: 12/26/2019
Publication Date: 1/23/2020
Citation: Chang, P.-K., Cary, J.W., Lebar, M.D. 2020. Biosynthesis of conidial and sclerotial pigments in Aspergillus species. Applied Microbiology and Biotechnology. 104:2277-2286. https://doi.org/10.1007/s00253-020-10347-y.
DOI: https://doi.org/10.1007/s00253-020-10347-y

Interpretive Summary: Pigments produced by fungi are chemically complex molecules that carry out a number of different functions for the producing organism including resistance to environmental stresses such as UV irradiation, heat and oxidative stress. Some pigments also help the fungus with respect to its ability to invade plants and animals during the disease process. This review gathers available research and discusses current knowledge on the formation of pigments in the Aspergillus group of fungi, especially those pigments associated with reproductive and survival structures such as conidia and sclerotia. It examines organization of genes involved in pigment production, their biosynthetic pathways and their biological functions. A better understanding of the structure and biosynthesis of fungal piments could facilitate strategies to mitigate fungal diseases of plants, animals and humans.

Technical Abstract: Fungal pigments, which are classified as secondary metabolites, are polymerized products derived mostly from phenolic precursors with remarkable structural diversity. Pigments of conidia and sclerotia are of myriad functions. They provide tolerance against various environmental stresses such as ultraviolet light, oxidizing agents, and ionizing radiation. Some pigments even play a role in fungal pathogenesis. This review gathers available research and discusses current knowledge on the formation of conidial and sclerotial pigments in Aspergilli. It examines organization of genes involved in pigment production, biosynthetic pathways, biological functions and reevaluates some of the current dogma, especially with respect to the DHN-melanin pathway, on the production of these enigmatic polymers. A better understanding of the structure and biosynthesis of melanins and other pigments could facilitate strategies to mitigate fungal pathogenesis.