The Effect of Fusarium verticillioides Fumonisins on Fatty Acids, Sphingolipids, and Oxylipins in Maize Germlings

Abstract

Fusarium verticillioides causes multiple diseases of Zea mays (maize) including ear and seedling rots, contaminates seeds and seed products worldwide with toxic chemicals called fumonisins. The role of fumonisins in disease is unclear because, although they are not required for ear rot, they are required for seedling diseases. Disease symptoms may be due to the ability of fumonisins to inhibit ceramide synthase activity, the expected cause of lipids (fatty acids, oxylipins, and sphingolipids) alteration in infected plants. In this study, we explored the impact of fumonisins on fatty acid, oxylipin, and sphingolipid levels in planta and how these changes affect F. verticillioides growth in maize. The identity and levels of principal fatty acids, oxylipins, and over 50 sphingolipids were evaluated by chromatography followed by mass spectrometry in maize infected with an F. verticillioides fumonisin-producing wild-type strain and a fumonisin-deficient mutant, after different periods of growth. Plant hormones associated with defense responses, i.e., salicylic and jasmonic acid, were also evaluated. We suggest that fumonisins produced by F. verticillioides alter maize lipid metabolism, which help switch fungal growth from a relatively harmless endophyte to a destructive necrotroph.

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“…In the present study, free sphingoid bases were more abundant in H21 than in H22 maize samples (Figure 3). This is in agreement with the disruption of CerS by FBs and the subsequent reduction in phytoceramide synthesis in highly contaminated samples, as previously reported by many authors (Zitomer et al, 2008;Dall' Asta et al, 2015;Beccaccioli et al, 2021). In agreement with Beccaccioli et al (2021), we observed an accumulation of S-LCFA in highly contaminated samples, thus confirming the preferential disruption of CerS2 homologs in maize.…”

“…It has been recently demonstrated that, among CerS isoforms, maize homologs of CerS2 are preferentially targeted by FBs, increasing therefore the formation of LCFA-sphinganine structures over VLCFA-phytosphingosine ones (Zitomer et al, 2008;Beccaccioli et al, 2021). Very recently, Beccaccioli et al (2021) suggested that FB-driven massive increase in free sphingoid bases and S-LCFA may represent a key signal for controlling programmed cell death in maize infected seedlings.…”

Light-Stress Response Mediated by the Transcription Factor KlMga2 in the Yeast Kluyveromyces lactis

“…Instrument setting was reported previously (Ludovici et al, 2014). The SIM parameters have been obtained by flow injection of authentic standard and agreed with the literature (Yang et al, 2009;Beccaccioli et al, 2021). FA mass and relative parameters of analysis are reported in Table 2.…”

Lipid Signaling Modulates the Response to Fumonisin Contamination and Its Source, Fusarium verticillioides, in Maize

“…acknowledged as a mycotoxin-susceptibility factor (Scala et al, 2014). However, it must be noted that C18:2 and C18:3 derived oxylipins are linked to early FBs accumulation stages as recently reported by several authors (Christensen and Kolomiets, 2011;Dall' Asta et al, 2012;Beccaccioli et al, 2021).…”