Intrtaction Of Fusarium Graminearum And Wheat

Trichothecenes are a group of secondary metabolites in Fusarium. Tri5, Tri6, Tri10 and Tri12 are among the 16 trichothecene biosynthesis genes reported so far. In this study, we analyzed the expression level of Tri5,, Tri6, TrilO and Tri12 during the interaction between Fusarium graminearum and wheat by using RT-PCR technology and Molecular Analyst software (Bio-Rad Quantity One). We observed that there is no detectable level of expression of the four genes at 0—12 hai (hours after inoculation). At 24 hai, the relative expression level of Tri5 in resistant cultivar Sumai 3 and susceptible cultivar Ningmai 6 had no significant difference. But at 36~72 hai, the expression level of Tri5 in Ningmai 6 was about twice of that in Sumai 3. The relative expression of Tri6 and TrilO showed no significant difference at all time points whether it was on resistant or susceptible cultivar. At 48 hai and 72 hai, the relative expression of Tril2 in Ningmai 6and Sumai 3 showed significant difference, the former being 4.4 times and 4.9 times of the latter. Thus we hypothesized that Sumai 3 may not only degrade trichothecenes, but also inhibit the transport of trichothecenes as well.We also collected wheat heads showing symptoms of Fusarium head blight from 13 provinces of China. A total of 316 isolates of Fusarium graminearum were subjected to differentiation of the isolates that produce NIV-, DON, 3-ADON, and 15-ADON, respectively, using PCR with two sets (four of each) of primers. The results showed that 49 isolates (15.5%) produced NIV, 136 isolates (43.0%) produced DON and 15-ADON, 131 isolates (41.5%) produced DON and 3-ADON. In summary, most isolates produce DON. Among those isolates, the 15-ADON-producing isolates were not found in Jiangsu Province and Anhui Province, the 3-ADON-producing isolates were not found in Fujian Province and Zhejiang Province, the NIV-producing isolates were not found in Hubei Province and Henan Province. The isolates from Hebei Province, Ningxia Province and Shandong Province only produce DON and 15-ADON, while the isolates from Jiangxi Province only produce DON and 3-ADON, and the isolates from Sichuan Province only produce NIV. The isolates from Heilongjiang Province and Guizhou Province canproduce all four tested toxins. No significant correlation between Fusarium graminearum toxin-producing ability and their lineage designation and wheat cultivars from which they were isolated from was shown.