P-165 - The search for efficient Blumeria hordei effector delivery systems to barley host cells

Wednesday, July 16, 2025

13:30 - 15:15

Location: Confex Hall 3

Effector Interference Mechanisms

Presenting Author(s)

ID

Ishani Shankar Das

Postdoctoral researcher
University of Cologne
Cologne, Nordrhein-Westfalen, Germany

Author(s)

JW

Janina Werner

Postdoctoral researcher
University of Cologne
Cologne, Nordrhein-Westfalen, Germany
GD

Gunther Doehlemann

Professor
University of Cologne
Cologne, Nordrhein-Westfalen, Germany
IS

Isabel Saur

Group leader
University of Cologne, CEPLAS
Cologne, Nordrhein-Westfalen, Germany

Barley (Hordeum vulgare) is one of the most important crops in the European landscape. It faces a major threat from the airborne powdery mildew fungus Blumeria hordei (Bh). The obligate biotrophic lifestyle of Bh is associated with the lack of stable transformation tools to molecularly study Bh virulence and pathogenicity. As such, the knowledge on the secretion, molecular function and redundancy of Bh effectors remains comparatively sparse. We set out to make use of the avirulence function of Bh AVR_A effectors, i.e., their ability to activate cell death and resistance mediated by MLA NLRs, as a marker to screen efficient heterologous expression and microbial-assisted delivery systems for the translocation of Bh effector proteins into cereal host cells. For this, we focus on utilising the bacterial Type III Secretion System and signal peptide-mediated secretion from genetically amenable fungal pathogens of barley. We monitor AVR_A-induced activation of MLA-mediated cell death and pathogen resistance, with most progress being made on the delivery of the Bh AVR_A13 effector via ectopic expression in Ustilago hordei. With this study, we aim to establish efficient ways of Bh effector delivery to widen the scope of powdery mildew research.