Alien chromatin other than the GST-encodingFhb7candidate confers Fusarium head blight resistance in wheat breeding

The lack of resistance resources is a major bottleneck for wheat Fusarium head blight (FHB) resistance breeding. Three wheat- Th. elongatum FHB resistant translocation lines have been developed and used for wheat breeding without yield penalty. Transcriptomic analysis identified a derivative glutathione S-transferase transcript T26102, which was homologous to Fhb7 and induced dramatically by Fusarium graminearum . Unlike other studies, Fhb7 homologs were detected not only in Thinopyrum but also in Elymus , Leymus , Pseudoroegeria and Roegeria . We also found that several wheat- Th. ponticum derivatives carrying Fhb7 and its homologs were highly susceptible to FHB. Moreover, the transgenic plants expressing Fhb7 and its homolog on different backgrounds did not improve the FHB resistance. One Sentence Summary The GST-encoding Fhb7 candidate cannot improve Fusarium head blight resistance in wheat breeding.