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ARS Home » Plains Area » Lincoln, Nebraska » Wheat, Sorghum and Forage Research » Research » Publications at this Location » Publication #404933
Research Project: Genetic Improvement of Sorghum for Bioenergy, Feed, and Food Uses

Location: Wheat, Sorghum and Forage Research

Title: Elucidating the mechanism behind increased type-II resistance to fusarium head blight and reduced deoxynivalenol accumulation in wheat lines onstitutively expressing the sorghum phenylpropanoid pathway gene, SbCCoAOMT

Author
item SINGLA, SHIV - University Of Nebraska
item Palmer, Nathan - Nate
item O`Neill, Patrick
item DURAY, ZACHARY - Illinois Crop Improvement Association
item DILL-MACKY, RUTH - University Of Minnesota
item WEGULO, STEPHEN - University Of Nebraska
item Sattler, Scott
item Funnell-Harris, Deanna

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/9/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Fusarium head blight (FHB) is a devastating disease of wheat, primarily caused by Fusarium graminearum, which reduces yield and contaminates the grain with mycotoxins like deoxynivalenol (DON). Since resistance to FHB is quantitative, it is important to identify additional genes conferring resistance against it so that genes with small effects can be stacked to incrementally increase FHB-resistance. We examined if the constitutive expression of the sorghum genes SbCCoAOMT (caffeoyl-CoA O-methyltransferase) and SbC3’H (p-coumarate 3-hydroxylase) in monolignol biosynthesis, part of the phenylpropanoid pathway, in the moderately-susceptible spring wheat CB037, provides resistance to F. graminearum (Type-II resistance, spread in the spike) and reduces levels of DON. Assessment of four constitutive expression lines (CCoAOMT413, CCoAOMT421, C3H112, C3H222) showed that CCoAOMT413 had significantly reduced disease severity, as determined by the area under the disease progress curve (AUDPC), Fusarium-damaged kernels (FDK), and DON content compared to CB037 (P = 0.05). To elucidate possible mechanisms for the increased Type-II resistance and reduced DON, global gene expression analysis of CCoAOMT413, CCoAOMT421, and CB037 at 12- and 72-hours post-inoculation (hpi) was performed. At 72 h post-inoculation with F. graminearum, 1,482 genes were uniquely upregulated, and 1,047 genes were uniquely downregulated in CCoAOMT413. Gene ontology enrichment and heatmap analysis of genes showed that several defense-related and toxin export/metabolization biological processes had the highest expression in the CCoAOMT413 line inoculated with F. graminearum at 72 hpi, including phenylpropanoid and jasmonic acid biosynthesis pathways, WRKY transcription factors, and glutathione-S-transferases. Phloroglucinol staining (which stains lignin and feruloyl end-groups) of cross-sections from the rachis at 72 hpi showed, that F. graminearum-inoculated CCoAOMT413 and CCoAOMT421 lines were more stained than their mock counterparts and F. graminearum-inoculated CB037, suggesting a potential increase in secondary metabolite deposition that could have contributed to increased resistance in CCoAOMT413. Information from this study can be used to aid future breeding efforts to improve F. graminearum resistance in wheat, reduce contamination with DON, and increase grain quality.