title: Heat- and cold-shock responses in Fusarium graminearum 3 acetyl- and 15 acetyl-deoxynivalenol chemotypes.
abstract: Fusarium graminearum Schwabe is the primary cause of Fusarium head blight (FHB) in North America. Chemically distinct F. graminearum sub-populations can be identified based on the type or composition of deoxynivalenol (DON) mycotoxin derivatives, including 3-acetyl (3-ADON) and 15-acetyl (15-ADON). The evaluation of randomly selected 3-ADON and 15-ADON isolates, collected from spring wheat throughout Canada, was performed using thin layer chromatography (TLC), high-performance liquid chromatography (HPLC), ice-nucleation activity (INA), and heat and cold tolerance tests conducted within a temperature range of -70°C to 65°C. The results indicated that the 3-ADON sub-population, which is responsible for the highest disease severity and has rapidly displaced the 15-ADON sub-population, produces more DON and zearalenone (ZEA) than the 15-ADON sub-population when exposed to heat and cold. Following exposures (1 and 2 h) to extremely high or low temperatures, 3-ADON isolates exhibited faster mycelial growth than 15-ADON isolates. In addition, the warmest temperature at which INA activity occurred was in 3-ADON (-3.6°C) vs. 15-ADON (-5.1°C). Taken together, these features suggest that the newly emerging 3-ADON sub-population is more resilient than the resident 15-ADON sub-population. Overall, the differences between the two sub-populations could provide new insights into FHB epidemiology and if validated under field conditions, may provide important information for predicting future FHB epidemics.
authors.affiliation: Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK, S7N 5A8, Canada. vladimir.vujanovic@usask.ca
authors.forename: Vladimir
authors.initials: V
authors.lastname: Vujanovic
authors.forename: Yit Kheng
authors.initials: YK
authors.lastname: Goh
authors.forename: Prasad
authors.initials: P
authors.lastname: Daida
mesh_terms: D002170:Canada; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D003080:Cold Temperature; D058639:Cold-Shock Response; D005670:Fusarium / Q000737:chemistry* / Q000254:growth & development / Q000528:radiation effects*; D018869:Heat-Shock Response; D006358:Hot Temperature; D013997:Time Factors; D014255:Trichothecenes / Q000032:analysis*; D014908:Triticum / Q000382:microbiology
chemical_list: D014255:Trichothecenes; C007262:deoxynivalenol