Plant-specific NAC transcription factors are well known to play important roles in developmental processes and responses to environmental stresses, whereas little is known about their functions in response to biotic stresses in crops.In this study, a new NAC gene TaNAC1, a member of NAC1 subgroup, were cloned from bread wheat and characterized.There is a highly hydrophobic negative regulatory domain (NRD) in TaNAC1, which acts to suppress transcriptional activity.TaNAC1 was strongly expressed in wheat root.By qRT-PCR analysis of its expression pattern, we found that TaNAC1 was involved in wheat response to obligate pathogen Puccinia striiformis f.sp.tritici infection and defence-related hormone treatments of salicylic acid, methyl jasmonate and ethylene.TaNACl-overexpressing Arabidopsis plants exhibited enhanced susceptibility to Pseudomonas syringae and accelerated HR progress.While after pathogen infiltration, transgenic plants presented a modified expression pattern of defense gene markers (PR1, PR2 and PDF1.2).JA-signaling pathway genes PDF1.2 and ORA59 were consititutively expressed in transgenic plants.On the other hand, TaNAC1 did not block SA biosynthesis and its signaling pathway.Moreover, TaNAC1-overexpressing in Arabidopsis resulted that more lateral root developed and the primary root elongation growth was suppressed.Therefore, TaNAC1 was the first reported NAC gene isolated from wheat which was involved in the control of root development.Collectively, these results suggested that TaNAC1 was an important positive regulatory component of the plant JA-signalling defence cascade.