Characterization of the Exo-Metabolome of the Emergent Phytopathogen <i>Fusarium kuroshium</i> sp. nov., a Causal Agent of <i>Fusarium</i> Dieback

• Main Authors: Angélica Gutiérrez-Sánchez, Javier Plasencia, Juan L. Monribot-Villanueva, José B. Rodríguez-Haas, Jose Abel López-Buenfil, Clemente J. García-Ávila, Eliel Ruiz-May, Diana Sánchez-Rangel, José A. Guerrero-Analco
• Format: Article
• Language: English
• Published: MDPI AG 2021-04-01
• Series: Toxins
• Subjects: exo-metabolome; fusaric acid; <i>Fusarium</i> dieback; <i>Fusarium kuroshium</i>; fungal metabolomics; <i>Persea americana</i> (avocado)
• Online Access: https://www.mdpi.com/2072-6651/13/4/268

<i>Fusarium kuroshium</i> is the fungal symbiont associated with the ambrosia beetle <i>Euwallacea kuroshio</i>, a plague complex that attacks avocado, among other hosts, causing a disease named <i>Fusarium</i> dieback (FD). However, the contribution of <i>F. kuroshium</i> to the establishment of this disease remains unknown. To advance the understanding of <i>F. kuroshium</i> pathogenicity, we profiled its exo-metabolome through metabolomics tools based on accurate mass spectrometry. We found that <i>F. kuroshium</i> can produce several key metabolites with phytotoxicity properties and other compounds with unknown functions. Among the metabolites identified in the fungal exo-metabolome, fusaric acid (FA) was further studied due to its phytotoxicity and relevance as a virulence factor. We tested both FA and organic extracts from <i>F. kuroshium</i> at various dilutions in avocado foliar tissue and found that they caused necrosis and chlorosis, resembling symptoms similar to those observed in FD. This study reports for first-time insights regarding <i>F. kuroshium</i> associated with its virulence, which could lead to the potential development of diagnostic and management tools of FD disease and provides a basis for understanding the interaction of <i>F. kuroshium</i> with its host plants.