Single Nucleotide Polymorphisms in B-Genome Specific UDP-Glucosyl Transferases Associated with Fusarium Head Blight Resistance and Reduced Deoxynivalenol Accumulation in Wheat Grain

Abstract

An in vitro spike culture method was optimized to evaluate Fusarium head blight (FHB) resistance in wheat (Triticum aestivum) and used to screen a population of ethyl methane sulfonate treated spike culture-derived variants (SCDV). Of the 134 SCDV evaluated, the disease severity score of 47 of the variants was ≤30%. Single nucleotide polymorphisms (SNP) in the UDP-glucosyltransferase (UGT) genes, TaUGT-2B, TaUGT-3B, and TaUGT-EST, differed between AC Nanda (an FHB-susceptible wheat variety) and Sumai-3 (an FHB-resistant wheat cultivar). SNP at 450 and 1,558 bp from the translation initiation site in TaUGT-2B and TaUGT-3B, respectively were negatively correlated with FHB severity in the SCDV population, whereas the SNP in TaUGT-EST was not associated with FHB severity. Fusarium graminearum strain M7-07-1 induced early expression of TaUGT-2B and TaUGT-3B in FHB-resistant SCDV lines, which were associated with deoxynivalenol accumulation and reduced FHB disease progression. At 8 days after inoculation, deoxynivalenol concentration varied from 767 ppm in FHB-resistant variants to 2,576 ppm in FHB-susceptible variants. The FHB-resistant SCDV identified can be used as new sources of FHB resistance in wheat improvement programs.

Spike culture derived wheat (Triticum aestivum L.) variants exhibit improved resistance to multiple chemotypes of Fusarium graminearum

“…Petch] strains (M9-07-1, M1-07-2, Carman-NIV, China-Fg809, and Carman-705-2) procured from the former Cereal Research Centre (Agriculture and Agri-Food Canada, Winnipeg, MB, Canada). The Fusarium strains were regrown in liquid culture to the required macroconidia concentrations as previously described [35].…”

“…Spikes from AC Nanda and Sumai-3 were point inoculated with varying volume (10, 15 and 20 μL) of inoculum at 10 5 macroconidia/mL concentration with different chemotypes, covered with moist plastic bags for three days to facilitate fungal infection and placed in a Sanyo versatile test chamber (Sanyo-MIR351H, Canada) at 16/8 h day/night cycle with 26/24°C temperature and disease severity determined as previously described [35].…”

“…Fifty-five spike culture derived variants (SCDV) were selected based on their FHB reaction from a population of 134 SCDV lines developed in previous study [35]. The selected SCDV lines at M 3 stage were grown in a greenhouse during May-July 2016 with 16/8 h of day/night cycle with average daily temperature of 27.3/20.6°C and relative humidity of 50.1/70.5%.…”

“…graminearum would be valuable. Therefore, the objective of the present study is to identify spike culture derived wheat variants (SCDV) [34, 35] resistant to multiple F . graminearum chemotypes which can be utilized in breeding programs to develop wheat genotypes with broad spectrum FHB resistance.…”

“…graminearum chemotypes which can be utilized in breeding programs to develop wheat genotypes with broad spectrum FHB resistance. The SCDV was previously developed by ethyl methane sulfonate (EMS) mutagenesis [34] and shown to exhibit a range of FHB disease severity using an immature spike culture screening method [35].…”