Phytotoxicity Evaluation of Type B Trichothecenes Using a Chlamydomonas reinhardtii Model System

Abstract

Type B trichothecenes, which consist of deoxynivalenol (DON) and nivalenol (NIV) as the major end products, are produced by phytotoxic fungi, such as the Fusarium species, and pollute arable fields across the world. The DON toxicity has been investigated using various types of cell systems or animal bioassays. The evaluation of NIV toxicity, however, has been relatively restricted because of its lower level compared with DON. In this study, the Chlamydomonas reinhardtii testing system, which has been reported to have adequate NIV sensitivity, was reinvestigated under different mycotoxin concentrations and light conditions. The best concentration of DON and NIV, and their derivatives, for test conditions was found to be 25 ppm (2.5 × 10−2 mg/mL). In all light test conditions, DON, NIV, and fusarenon-X (FusX) indicated significant growth inhibition regardless of whether a light source existed, or under differential wavelength conditions. FusX growth was also influenced by changes in photon flux density. These results suggest that C. reinhardtii is an appropriate evaluation system for type B trichothecenes.

Cytotoxic trichothecene-type sesquiterpenes from the sponge-derived fungusStachybotrys chartarumwith tyrosine kinase inhibition

“…Apotrichothecene-based analogues with a sugar moiety at C-12 and without hydroxy group at C-2 and C-4 (1) or with a methoxy group at C-2 (2) showed weaker cytotoxicity in comparison with the 2,4,12-trihydroxy analogue (14). For the trichodermol-type analogues, those with a macrocyclic ring along with a tetrahydropyran ring (5,6,8) exerted remarkable effects, whereas the analogues without a tetrahydropyran ring in the macrocyclic moiety (4,9) showed less cytotoxicity. However, compound 10 is an exception which showed IC 50 within 10 nM, while the structural distinction of 4 and 10 was attributed to the olenic rearrangement and the substitution at C-7 00 of the macrocyclic ring.…”

“…Trichothecenes are a group of sesquiterpene-based mycotoxins, [1][2][3][4][5][6] which are markedly cytotoxic toward eukaryotic organisms, 7 including high phytotoxicity. [8][9][10] The mechanism of toxicity is attributed to the inhibition of protein and DNA synthesis, and the mitochondrial electron transport system. 11,12 Biogenetically, the mevalonate pathway is involved in the generation of this typical scaffold and chemically related derivatives such as apotrichothecene-type and sambucinol-type analogues.…”

“…During our study on antitumor-active metabolites from marinederived fungi, we found that the EtOAc extract of a rice solid cultured fungus, Stachybotrys chartarum, isolated from a sponge (Niphates recondite), showed signicant cytotoxicity against a panel of tumor cell lines including HCT-116 and HepG2 with IC 50 values <10 mg mL À1 . This fungus was then subjected to large-scale fermentation, while chromatographic separation of the EtOAc fraction resulted in the isolation of 15 trichothecenebased sesquiterpenes (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15) (Fig. 1).…”

Direct and host‐mediated interactions between Fusarium pathogens and herbivorous arthropods in cereals

“…Reports indicate that while mycotoxin levels do not commonly breach legal limits (Streit et al ., ; Marin et al ., ; Bĕláková et al ., ), different geographic areas are at a higher risk of approaching these limits than others under favourable weather conditions (Placinta et al ., ; Cui et al ., ). Different acetylated forms of DON and NIV, varying in their toxicity, phytotoxicity (Suzuki & Iwahashi, ) and geographical distribution (Gale et al ., ), are produced by different pathogen strains. FER of maize is typically caused by Fusarium verticillioides (formerly Fusarium moniliforme ).…”

Contrasting Roles of Deoxynivalenol and Nivalenol in Host-Mediated Interactions between Fusarium graminearum and Sitobion avenae

“…Wheat coleoptile growth was severely inhibited by DON, whereas the effect of NIV was no different to negative controls [11]. In Chlamydomonas reinhardtii , toxicity of NIV was detectable, but less still than that of DON [14]. Neither of these studies truly demonstrates the phytotoxic effects to cereal spikes at the site of head blight disease, but indicates that the phytotoxicity of NIV is less than that of DON and is host dependent.…”