Pathogen-inducible Ta-Lr34res Expression Confers Disease Resistance in Barley

The Ta-Lr34res gene confers partial, durable, and broad spectrum resistance against several fungal pathogens in wheat (Triticum aestivum). Transgenic barley (Hordeum vulgare) lines expressing Ta-Lr34res showed enhanced resistance against powdery mildew and leaf rust. While the gene is only active at adult stage in wheat, Ta-Lr34res was found to be already highly expressed at the seedling stage in transgenic barley, resulting in severe negative effects on growth.

To solve this, University of Zurich researchers expressed Ta-Lr34res under the control of the pathogen-inducible Hv-Ger4c promoter in barley. The resulting transformants showed strong resistance against leaf rust and powdery mildew. The transformed events also had similar grain production compared to susceptible wild types.

These results showed that negative effects caused by early high expression of Ta-Lr34res can be eliminated by inducible expression without compromising disease resistance.

For more information, read the article in Plant Biotechnology Journal.