A wheat NAC interacts with an orphan protein and enhances resistance to Fusarium head blight disease

Abstract

Summary Taxonomically‐restricted orphan genes play an important role in environmental adaptation, as recently demonstrated by the fact that the Pooideae‐specific orphan TaFROG (Triticum aestivum Fusarium Resistance Orphan Gene) enhanced wheat resistance to the economically devastating Fusarium head blight (FHB) disease. Like most orphan genes, little is known about the cellular function of the encoded protein TaFROG, other than it interacts with the central stress regulator TaSnRK1α. Here, we functionally characterized a wheat (T. aestivum) NAC–like transcription factor TaNACL‐D1 that interacts with TaFROG and investigated its’ role in FHB using studies to assess motif analyses, yeast transactivation, protein‐protein interaction, gene expression and the disease response of wheat lines overexpressing TaNACL‐D1. TaNACL‐D1 is a Poaceae‐divergent NAC transcription factor that encodes a Triticeae‐specific protein C‐terminal region with transcriptional activity and a nuclear localisation signal. The TaNACL‐D1/TaFROG interaction was detected in yeast and confirmed in planta, within the nucleus. Analysis of multi‐protein interactions indicated that TaFROG could form simultaneously distinct protein complexes with TaNACL‐D1 and TaSnRK1α in planta. TaNACL‐D1 and TaFROG are co‐expressed as an early response to both the causal fungal agent of FHB, Fusarium graminearum and its virulence factor deoxynivalenol (DON). Wheat lines overexpressing TaNACL‐D1 were more resistant to FHB disease than wild type plants. Thus, we conclude that the orphan protein TaFROG interacts with TaNACL‐D1, a NAC transcription factor that forms part of the disease response evolved within the Triticeae.

An orphan protein of Fusarium graminearum modulates host immunity by mediating proteasomal degradation of TaSnRK1α

“…It is likely that TaFROG functions in defense against F. graminearum by protecting TaSnRK1α against Osp24-mediated degradation. A recent report showed that TaFROG also interacts with TaNACL-D1, a Poaceae-divergent NAC transcription factor with its NAC C-terminal region specific to the Triticeae, to enhance FHB resistance independent of its interaction with TaSnRK1α 29 . It is possible that Osp24 also interacts with TaNACL-D1 to suppress defense against FHB.…”

“…Overexpression of TaFROG that encodes a Pooideae-specific orphan protein induced by DON treatment also increased resistance against F. graminearum 28 . In wheat, TaFROG interacts with the TaSnRK1α protein kinase 28 and a NAC transcription factor 29 . Although germplasm with complete resistance or immunity to F. graminearum is lacking, more than 50 quantitative trait loci (QTLs) conferring various degrees of FHB resistance have been identified in wheat.…”

Taxonomically Restricted Wheat Genes Interact With Small Secreted Fungal Proteins and Enhance Resistance to Septoria Tritici Blotch Disease

“…The Pooideae-restricted gene TaFROG (Triticum aestivum Fusarium Resistance Orphan Gene) was shown to enhance wheat resistance to the Fusarium mycotoxin and virulence factor deoxynivalenol (DON) and it also enhanced resistance to Fusarium head blight (FHB) caused by Fusarium graminearum. TaFROG interacts with proteins of diverse cellular function, including the evolutionarily conserved SnRK1 (Sucrose-non-Fermenting Kinase) subfamily, illustrating TRG integration into conserved signaling processes (Perochon et al, 2015(Perochon et al, , 2019.…”

Comprehensive genomic characterization of NAC transcription factor family and their response to salt and drought stress in peanut

“…For example, the poplar NAC13 gene plays a vital role in the salt stress response [20]. Over-expression of a wheat NAC (TaNACL-D1) enhances resistance to Fusarium head blight disease [21], TaNAC30 negatively regulates the resistance of wheat to stripe rust [22], and TaNAC29 can provide salt stress tolerance by enhancing the antioxidant systems [23]. Over-expression of TsNAC1 from the halophyte Thellungiella halophila was shown to improve abiotic stress resistance, especially salt stress tolerance [24].…”