Fusarium head blight (FHB) is a destructive disease of wheat in many warm and humid areas worldwide. As a wheat relative, Thinopyrum elongatum showed high resistance to FHB and a novel FHB-resistant gene was located to chromosome 7EL by performing FHB resistance evaluation on a whole set of wheat-Th. elongatum addition lines. A wheat-Th. elongatum translocation line Zhongke 1878 was developed by irradiating the wheat-Th. elongatum addition line Chinese Spring (CS)-7EL using γ rays and identified as resistant to FHB. In order to explore the nature of FHB resistance, full-length transcripts sequencing was performed on the line Zhongke 1878. Twenty-five transcripts were identified specific for alien chromatin, among which the transcript T26102 was induced dramatically by Fusarium graminearum. Sequence comparison revealed that T26102 was homologous to the glutathione S-transferases (GST)-encoding Fhb7 cloned from the newly assembled Th. elongatum genome. However, some artificially synthetic wheat-Thinopyrum translocation lines and wheat-Thinopyrum partial amphiploid with Fhb7 homolog were identified as susceptible to FHB. In order to further verify the GST function on FHB resistance, the expression vectors of T26102 and its homolog Fhb7 were transformed into multiple wheat receptors. Regardless of the ubiquitin promoter or the native promoter as reported, no FHB resistance improvement was observed in the positive transgenic plants. Based on these results, our study provided evidence that GST from Thinopyrum was induced by F. graminearum, but is not decisive for FHB resistance.