The TaNAC29L-B-TaNAC1L-A module negatively regulates wheat sharp eyespot resistance by reducing lignin content though...

Wheat sharp eyespot is a soil-borne disease caused by the necrotrophic fungal pathogen Rhizoctonia cerealis, which poses a serious threat to wheat production. NAC transcription factors (TFs) play critical roles in plant immune responses. However, the functional mechanisms of NAC TFs in wheat resistance to R. cerealis remain unclear. In this study, we investigate the role and molecular mechanisms of TaNAC29L-B in wheat defense against R. cerealis. Through gene overexpression, silencing, RNA-seq, chromatin immunoprecipitation sequencing (ChIP-seq), yeast one-hybrid (Y1H), electrophoretic mobility shift assay (EMSA), and dual-luciferase reporter assays, we demonstrated that TaNAC29L-B directly represses the expression of TaPAL4-B, leading to a reduction in lignin content and thereby negatively impacting the resistance of wheat to R. cerealis. Additionally, yeast two-hybrid screening identified another NAC TF, TaNAC1L-A, which interacts with TaNAC29L-B both in vivo and in vitro. Notably, TaNAC1L-A also directly represses TaPAL4-B expression, and this repression is further enhanced through its interaction with TaNAC29L-B. This study provides new insights into the role of NAC TFs in the wheat immune regulatory network and offers candidate genes for molecular breeding of wheat varieties with improved resistance to sharp eyespot.