Transcriptome and Hormonal Analysis of <i>Agaricus bisporus</i> Basidiome Response to <i>Hypomyces perniciosus</i> Infection

Abstract

<i>Agaricus</i> <i>bisporus</i> (Lange) Imbach is the most widely cultivated mushroom in the world. <i>A. bisporus</i> wet bubble disease is one of the most severe diseases of white button mushrooms and is caused by the fungal pathogen <i>Hypomyces perniciosus</i>. The pathogen causes a drastic reduction in mushroom yield because of malformation and deterioration of the basidiomes. However, the mechanism of the button mushroom's malformation development after infection with <i>H. perniciosus</i> remains obscure. Therefore, to reveal the mechanism of <i>A. bisporus</i> malformation caused by <i>H. perniciosus</i>, the interaction between the pathogen and host was investigated in this study using histopathological, physiological, and transcriptomic analyses. Results showed that irrespective of the growth stages of <i>A. bisporus</i> basidiomes infected with <i>H. perniciosus</i>, the host's malformed basidiomes and enlarged mycelia and basidia indicated that the earlier the infection with <i>H. perniciosus</i>, the more the malformation of the basidiomes. Analyzing physiological and transcriptomic results in tandem, we concluded that <i>H. perniciosus</i> causes malformation development of <i>A. bisporus</i> mainly by affecting the metabolism level of phytohormones (N⁶-isopentenyladenosine, cis-zeatin, and N⁶-[delta 2-isopentenyl]-adenine) of the host's fruiting bodies rather than using toxins. Our findings revealed the mechanism of the button mushroom's malformation development after infection with <i>H. perniciosus</i>, providing a reference for developing realistic approaches to control mushroom diseases. Our results further clarified the interaction between <i>A. bisporus</i> and <i>H. perniciosus</i> and identified the candidate genes for <i>A. bisporus</i> wet bubble disease resistance breeding. Additionally, our work provides a valuable theoretical basis and technical support for studying the interaction between other pathogenic fungi and their fungal hosts.