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

Abstract

Fusarium kuroshium is the fungal symbiont associated with the ambrosia beetle Euwallacea kuroshio, a plague complex that attacks avocado, among other hosts, causing a disease named Fusarium dieback (FD). However, the contribution of F. kuroshium to the establishment of this disease remains unknown. To advance the understanding of F. kuroshium pathogenicity, we profiled its exo-metabolome through metabolomics tools based on accurate mass spectrometry. We found that F. kuroshium 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 F. kuroshium 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 F. kuroshium 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 F. kuroshium with its host plants.

The biological relevance of the FspTF transcription factor, homologous of Bqt4, in Fusarium sp. associated with the ambrosia beetle Xylosandrus morigerus

“…as symbionts of ambrosia beetles are focused on its isolation and identification, phylogenetic analyzes, symbiotic interaction, and biological and chemical control (Eskalen et al, 2012;Freeman et al, 2013;O'Donnell et al, 2015;Carrillo et al, 2016Carrillo et al, , 2020Short et al, 2017;Guevara-Avendaño et al, 2018Kehelpannala et al, 2018;Mayorquin et al, 2018;Na et al, 2018;Grosman et al, 2019;Huang et al, 2020;Lynn et al, 2020;Takashina et al, 2020;Carreras-Villaseñor et al, 2022). However, there are scarce molecular analyzes related to genomics, transcriptomics, metabolomics, among others (Sánchez-Rangel et al, 2018;Sakai et al, 2020;Gutiérrez-Sánchez et al, 2021;Pérez-Torres et al, 2021;Ibarra-Laclette et al, 2022) that can give clues of the biological processes that are required for the infection of the plant host.…”