Metabolomics deciphers the host resistance mechanisms in wheat cultivar Sumai-3, against trichothecene producing and non-producing isolates of Fusarium graminearum

• Published in: Plant physiology and biochemistry Vol. 83; pp. 40 - 50
• Main Authors: Gunnaiah, Raghavendra, Kushalappa, Ajjamada C.
• Format: Journal Article
• Language: English
• Published: Paris Elsevier Masson SAS 01.10.2014; Elsevier
• Subjects: Biological and medical sciences; Deoxynivalenol; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Fusarium - pathogenicity; Fusarium head blight; Metabolomics; Phenylpropanoids and flavonoids; Phytopathology. Animal pests. Plant and forest protection; Plant physiology and development; Quantitative resistance; Sumai-3; Trichothecenes - biosynthesis; Trichothecenes non-producing mutants (Tri5-); Triticum - microbiology; Sumai-3; RR; FHB; RRC; UGT; Trichothecenes non-producing mutants (Tri5-); QTL; RRI; COMT; H2O2; LC-HRMS; PDC; C4H; qPCR; dpi; Fusarium head blight; PSD; Quantitative resistance; TDP; DON; CAD; Deoxynivalenol; CS; NIL; ROS; AUDPC; HCT; D3G; Phenylpropanoids and flavonoids; HCAA; PAL; FC; Metabolomics; Monocotyledones; Plant pathogen; Mycosis; Vomitoxin; Flavonoid; Mechanism; Fungi; Triticum; Gramineae; Angiospermae; Fungi Imperfecti; Fusarium graminearum; Trichothecenes non-producing mutants (Tri5; ); Host; Trichothecene; Infection; Toxin; Plant physiology; Isolate; Spermatophyta; Phenylpropanoids; Nonspecific resistance; Mutation; Cultivar; Trichothecenes non-producing mutants (Tri5(-))
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2014.07.002

Fusarium head blight (FHB) of wheat, caused by Fusarium graminearum, reduces grain yield and contaminates grains with trichothecene mycotoxins. Host resistance to FHB is quantitatively inherited and more than 100 QTLs have been mapped, but the host resistance mechanisms are poorly understood. Non-targeted metabolic profiling was applied to elucidate the host resistance mechanisms to FHB spread through rachis of wheat cultivar Sumai-3 against both trichothecene producing and non-producing isolates of Fusarium graminearum. The accumulation of deoxynivalenol (DON) in Sumai-3 was low, however the resistance to spread was not due to its detoxification into DON-3-O-glucoside (D3G), as the proportion of total DON converted to D3G in the resistant was not significantly different from that in the susceptible cultivar Roblin. Instead, the resistance was considered to be due to the accumulation of resistance related (RR) metabolites belonging to the phenylpropanoid pathway that reduced pathogen advancement through increased host cell wall thickening and also reduced pathogen growth due to antifungal and/or antioxidant properties which, in turn, reduced subsequent trichothecene biosynthesis. The RR phenylpropanoids accumulated in Sumai-3 were mainly the preformed syringyl rich monolignols and their glucosides, which are precursors of lignin biosynthesis, as well as antimicrobial flavonoids. The resistant cultivar Sumai-3 inoculated with trichothecene producing F. graminearum not only accumulated less RR metabolites but also the abundance of many RR metabolites was lesser than in the trichothecene non-producing F. graminearum. This implies repression of host resistance mechanisms by trichothecenes/DON, which is a protein biosynthesis inhibitor. Enhancement of resistance in wheat against FHB can be exploited through stacking of candidate phenylpropanoid pathway genes. •Resistance in Sumai-3 cultivar to fusarium head blight (FHB) is mainly due to phenylpropanoid and flavonoid metabolites.•Antimicrobial compounds and cell wall thickening, by hydroxycinnamic acid amides, in Sumai-3 resist FHB.•Trichothecene mycotoxins (DON) repressed resistance related metabolites production in Sumai-3.•Resistance in Sumai-3 is not related to the deoxynivalenol (DON) detoxification by host.