title: Detoxification of α-tomatine by Cladosporium fulvum is required for full virulence on tomato.
abstract: · α-Tomatine is an antifungal glycoalkaloid that provides basal defense to tomato (Solanum lycopersicum). However, tomato pathogens overcome this basal defense barrier by the secretion of tomatinases that degrade α-tomatine into the less fungitoxic compounds β-tomatine and tomatidine. Although pathogenic on tomato, it has been reported that the biotrophic fungus Cladosporium fulvum is unable to detoxify α-tomatine. · Here, we present a functional analysis of the glycosyl hydrolase (GH10), CfTom1, which is orthologous to fungal tomatinases. · We show that C. fulvum hydrolyzes α-tomatine into tomatidine in vitro and during the infection of tomato, which is fully attributed to the activity of CfTom1, as shown by the heterologous expression of this enzyme in tomato. Accordingly, ∆cftom1 mutants of C. fulvum are more sensitive to α-tomatine and are less virulent than the wild-type fungus on tomato. · Although α-tomatine is thought to be localized in the vacuole, we show that it is also present in the apoplast, where it is hydrolyzed by CfTom1 on infection. The accumulation of tomatidine during infection appears to be toxic to tomato cells and does not suppress defense responses, as suggested previously. Altogether, our results show that CfTom1 is responsible for the detoxification of α-tomatine by C. fulvum, and is required for full virulence of this fungus on tomato.
authors: Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708, PB Wageningen, the Netherlands.
authors: Bilal
authors: B
authors: Ökmen
authors: Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708, PB Wageningen, the Netherlands.|Centre for BioSystems Genomics, PO Box 98, 6700, AB Wageningen, the Netherlands.|Netherlands Metabolomics Centre, Einsteinweg 55, 2333, CC Leiden, the Netherlands.
authors: Desalegn W
authors: DW
authors: Etalo
authors: Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708, PB Wageningen, the Netherlands.|Centre for BioSystems Genomics, PO Box 98, 6700, AB Wageningen, the Netherlands.
authors: Matthieu H A J
authors: MHAJ
authors: Joosten
authors: Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708, PB Wageningen, the Netherlands.|Centre for BioSystems Genomics, PO Box 98, 6700, AB Wageningen, the Netherlands.
authors: Harro J
authors: HJ
authors: Bouwmeester
authors: Centre for BioSystems Genomics, PO Box 98, 6700, AB Wageningen, the Netherlands.|Netherlands Metabolomics Centre, Einsteinweg 55, 2333, CC Leiden, the Netherlands.|Plant Research International, Bioscience, PO Box 16, 6700, AA Wageningen, the Netherlands.
authors: Ric C H
authors: RCH
authors: de Vos
authors: Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708, PB Wageningen, the Netherlands.|Centre for BioSystems Genomics, PO Box 98, 6700, AB Wageningen, the Netherlands.
authors: Jérôme
authors: J
authors: Collemare
authors: Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708, PB Wageningen, the Netherlands.|Centre for BioSystems Genomics, PO Box 98, 6700, AB Wageningen, the Netherlands.
authors: Pierre J G M
authors: PJGM
authors: de Wit
mesh_terms: D002963:Cladosporium / Q000201:enzymology / Q000235:genetics / Q000472:pathogenicity*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D006026:Glycoside Hydrolases / Q000378:metabolism; D018551:Solanum lycopersicum / Q000382:microbiology; D009154:Mutation / Q000235:genetics; D010802:Phylogeny; D018515:Plant Leaves / Q000382:microbiology; D014053:Tomatine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D014774:Virulence
chemical_list: D005656:Fungal Proteins; C484751:alpha-tomatine; C003677:tomatidine; D014053:Tomatine; D006026:Glycoside Hydrolases; C099475:tomatinase