An antibody that confers plant disease resistance targets a membrane‐bound glyoxal oxidase in Fusarium

Abstract

Plant germplasm resources with natural resistance against globally important toxigenic Fusarium are inadequate. CWP2, a Fusarium genus-specific antibody, confers durable resistance to different Fusarium pathogens that infect cereals and other crops, producing mycotoxins. However, the nature of the CWP2 target is not known. Thus, investigation of the gene coding for the CWP2 antibody target will likely provide critical insights into the mechanism underlying the resistance mediated by this disease-resistance antibody. Immunoblots and mass spectrometry analysis of two-dimensional electrophoresis gels containing cell wall proteins from Fusarium graminearum (Fg) revealed that a glyoxal oxidase (GLX) is the CWP2 antigen. Cellular localization studies showed that GLX is localized to the plasma membrane. This GLX efficiently catalyzes hydrogen peroxide production; this enzymatic activity was specifically inhibited by the CWP2 antibody. GLX-deletion strains of Fg, F. verticillioides (Fv) and F. oxysporum had significantly reduced virulence on plants. The GLX-deletion Fg and Fv strains had markedly reduced mycotoxin accumulation, and the expression of key genes in mycotoxin metabolism was downregulated. This study reveals a single gene-encoded and highly conserved cellular surface antigen that is specifically recognized by the disease-resistance antibody CWP2 and regulates both virulence and mycotoxin biosynthesis in Fusarium species.

Advances of Metabolomics in Fungal Pathogen–Plant Interactions

“…Plant pathogenic fungi can cause a serious reduction in the crop yield and affect the quality of agricultural products [34,35,36,37]. Revealing the infection mechanisms of the plant pathogenic fungi can help us to develop novel strategies to control fungal diseases.…”

Oxidoreductases and Reactive Oxygen Species in Conversion of Lignocellulosic Biomass

“…Another indication for a role of H 2 O 2 and H 2 O 2 -producing enzymes in pathogenicity is provided by two independent studies showing that Botrytis cinerea became less virulent upon deletion of genes encoding either superoxide dismutase (SOD) (230) or GLOX (231). Membrane-bound GLOX has also been implicated in pathogenesis for crop pest Fusarium species (232).…”

Characterization of a New Glyoxal Oxidase from the Thermophilic Fungus Myceliophthora thermophila M77: Hydrogen Peroxide Production Retained in 5-Hydroxymethylfurfural Oxidation

“…The central physiological function of GLOx remains unknown, but experimental reports reveal that the enzyme is important for hyphal tip development and pathogenicity [34,35]. Moreover, some GLOxes are linked to the cell Wall Stress-responsive Component (WSC) domain that is predicted to be a cell-wall and membrane protein in yeast and fungi associated with cell wall integrity and stress responses [36,37].…”