Transgenic wheat expressing Thinopyrum intermedium MYB transcription factor TiMYB2R-1 shows enhanced resistance to the take-all disease

Abstract

The disease take-all, caused by the fungus Gaeumannomyces graminis, is one of the most destructive root diseases of wheat worldwide. Breeding resistant cultivars is an effective way to protect wheat from take-all. However, little progress has been made in improving the disease resistance level in commercial wheat cultivars. MYB transcription factors play important roles in plant responses to environmental stresses. In this study, an R2R3-MYB gene in Thinopyrum intermedium, TiMYB2R-1, was cloned and characterized. The gene sequence includes two exons and an intron. The expression of TiMYB2R-1 was significantly induced following G. graminis infection. An in vitro DNA binding assay proved that TiMYB2R-1 protein could bind to the MYB-binding site cis-element ACI. Subcellular localization assays revealed that TiMYB2R-1 was localized in the nucleus. TiMYB2R-1 transgenic wheat plants were generated, characterized molecularly, and evaluated for take-all resistance. PCR and Southern blot analyses confirmed that TiMYB2R-1 was integrated into the genomes of three independent transgenic wheat lines by distinct patterns and the transgene was heritable. Reverse transcription–PCR and western blot analyses revealed that TiMYB2R-1 was highly expressed in the transgenic wheat lines. Based on disease response assessments for three successive generations, the significantly enhanced resistance to take-all was observed in the three TiMYB2R-1-overexpressing transgenic wheat lines. Furthermore, the transcript levels of at least six wheat defence-related genes were significantly elevated in the TiMYB2R-1 transgenic wheat lines. These results suggest that engineering and overexpression of TiMYB2R-1 may be used for improving take-all resistance of wheat and other cereal crops.

Components of priming‐induced resistance to Fusarium head blight in wheat revealed by two distinct mutants of Fusarium graminearum

“…Furthermore, MAPK cascades are hypothesized to direct the expression of WRKY transcription factors, which are important mediators of plant defence responses, and are also exclusively in PATs tri6Δ (Table ; Eulgem, ; Ross et al ., ). Similarly, transcription factors belonging to the Myb family, which are known to be involved in defence responses to fungal pathogens, are exclusive to PATs tri6Δ (Table ; Liu et al ., ). These results suggest that mutants varying in pathogenicity and inducing the priming response differentially (Fig.…”

Spot blotch disease of wheat: the current status of research on genetics and breeding

“…For instance, as already mentioned, overexpression of TaPIMP1 in transgenic wheats was shown to be involved in providing enhanced resistance against B. sorokiniana . Similarly, the TFs TabHLH060 and TaLHY (α1R MYB TF) were both shown to be upregulated due to infection by Puccinia striiformis that causes stripe rust (Wang et al ., ; Zhang et al ., ), and TiMYB2R , a Thinopyrum intermedium MYB TF was shown to provide enhanced resistance against take‐all disease caused by Gaeumannomyces graminis (Liu et al ., ); the take‐all disease affects the roots of cereals and is an important disease in winter wheat in western Europe. Therefore, it may be desirable to undertake further studies to explore fully the occurrence of specific TFs other than TaPIMP1 that may be involved in spot blotch resistance.…”

Current status and trends of wheat genetic transformation studies in China

“…Overexpression of TiERF1 enhances resistance to sharp eyespot in transgenic wheat (Chen et al 2008b). Transgenic wheat expressing Thinopyrum intermedium MYB transcription factor gene TiMYB2R-1 showed enhanced resistance to the take-all disease (Liu et al 2013). Moreover, TaNAC21/22, a novel NAC transcription factor from the NAM subfamily of wheat, negatively regulates resistance of wheat to stripe rust by interacting with tae-miR164 (Feng et al 2014); TaCLP1 gene encoding a putative plantacyanin protein from wheat is the target gene of tae-miR408, and plays an important role in regulating tolerance of host plants to high-salinity, heavy cupric stress and stripe rust (Feng et al 2013).…”