Overexpression of the pathogen-inducible wheat TaWRKY45 gene confers disease resistance to multiple fungi in transgenic wheat plants

Abstract

Recently we cloned and characterized the gene for the wheat transcription factor TaWRKY45 and showed that TaWRKY45 was upregulated in response to benzothiadiazole (BTH) and Fusarium head blight (FHB) and that its overexpression conferred enhanced resistance against F. graminearum. To characterize the functional role of TaWRKY45 in the disease resistance of wheat, in the present study we conducted expression analyses of TaWRKY45 with inoculations of powdery mildew and leaf rust and evaluated TaWRKY45-overexpressing wheat plants for resistance to these diseases. TaWRKY45 was upregulated in response to infections with Blumeria graminis, a causal fungus for powdery mildew, and Puccinia triticina, a causal fungus for leaf rust. Constitutive overexpression of the TaWRKY45 transgene conferred enhanced resistance against these two fungi on transgenic wheat plants grown under greenhouse conditions. However, the expression of two resistance-related genes, Pm3 and Lr34, was not induced by the inoculation with powdery mildew in TaWRKY45-overexpressing wheat plants. These results suggest that TaWRKY45 is involved in the defense responses for multiple fungal diseases in wheat but that resistance involving TaWRKY45 differs from at least Pm3 and/or Lr34-related resistance. Our present and previous studies indicate that TaWRKY45 may be potentially utilized to improve a wide range of disease resistance in wheat.

TaCPK2-A, a calcium-dependent protein kinase gene that is required for wheat powdery mildew resistance enhances bacterial blight resistance in transgenic rice

“…6B and Supplementary Table S4), suggesting a similar regulatory mechanism for TaCPK2-A in wheat. Thus, the result on WRKY45 here is in line with that of Bahrini et al (2011), where overexpression of TaWRKY45 conferred disease resistance to multiple fungal diseases in transgenic wheat plants, reinforcing the idea that TaCPK2-A plays a role in fungal resistance in wheat via its regulation on TaWRKY45 . Together, the current data indicate conserved mechanisms mediated by TaCPK2-A for powdery mildew (fungal) resistance in wheat and bacterial blight resistance in rice.…”

“…Similarly, overexpression of wheat WRKY45 gene confers disease resistance to multiple fungi in transgenic wheat plants (Bahrini et al , 2011). In rice, OsWRKY45-1 may play a role in regulating SA- and JA-signalling genes such as PAL1 , PAD4 , PR1a , NH1 , LOX , and PR1b , while OsWRKY45-2 regulated a set of partly overlapping genes ( PAL1 , ICS1 , PAD4 , PR1a , NH1 , OsWRKY13 , LOX , AOS2 , and PR1b ; Tao et al , 2009).…”

Elucidation of the molecular responses of a cucumber segment substitution line carrying Pm5.1 and its recurrent parent triggered by powdery mildew by comparative transcriptome profiling

“…For example, stripe mosaic virus-induced gene silencing of barley HvWRKY10 , HvWRKY19 , and HvWRKY28 compromised resistance-gene-mediated defense to PM [31]. Constitutive over-expression of the TaWRKY45 in transgenic wheat conferred enhanced resistance against Blumeria graminis (a causal fungus for PM) [32]. These observations implicated the important role of TFs in response to PM infection.

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Identification and Profiling of microRNAs and Their Target Genes in Tibetan Hulless Barley in Response to Barley Leaf Stripe (BLS) Infection

“…In Arabidopsis, the overexpression of WRKY45 or WRKY1 enhanced disease resistance and drought tolerance [44,67]. In wheat, the overexpression of WRKY45 enhanced disease resistance to multiple fungi [68]. In Swiss-Prot, the target of hvu-novel-91 was a WRKY (Gene ID: HORVU7Hr1G083270), which was located on chromosome 7H and annotated to encode a WRKY46 transcription factor of A. thaliana.…”