The somatic embryogenesis receptor kinase TaSERK1 participates in the immune response to Rhizoctonia cerealis infection by interacting and phosphorylating the receptor-like cytoplasmic kinase TaRLCK1B in wheat

The sharp eyespot, caused by necrotrophic pathogen Rhizoctonia cerealis, often causes serious yield loss in wheat ( Triticum aestivum ). However, the mechanisms underlying wheat resistant responses to the pathogen are still limited. In this study, we performed a genome-wide analysis of somatic embryogenesis receptor kinase (SERK) family in wheat. As a result, a total of 26 TaSERK candidate genes were identified from the wheat genome. Only 6 TaSERK genes on the chromosomes 2A, 2B, 2D, 3A, 3B, and 3D showed obvious heightening expression patterns in resistant wheat infected with R. cerealis compared than those un-infected wheat. Of them, the transcripts of 3 TaSERK1 homoeologs on the chromosomes 2A, 2B, and 2D were significantly up-regulated in the highest level compared to other TaSERKs. Importantly, silencing of TaSERK1 significantly impaired wheat resistance to sharp eyespot. Further bio-molecular assays showed that TaSERK1 could interact with the defence-associated receptor-like cytoplasmic kinase TaRLCK1B, and phosphorylated TaRLCK1B. Together, the results suggest that TaSERK1 mediated resistance responses to R. cereali s infection by interacting and phosphorylating TaRLCK1B in wheat. This study sheds light on the understanding of the wheat SERKs in the innate immunity against R. cerealis, and provided a theoretical fulcrum to identify candidate resistant genes for improving wheat resistance against sharp eyespot in wheat.