Poster

Siddharthan Lakshmanan ^1,2, Monique Power ^1,2, Whynn Bosnich ¹, Nathan Liang ¹, Indira Thapa ¹, Jennifer Zantinge ³, Michael Holtz ³, Jean-Sebastien Parent ¹, Barbara Blackwell ¹, Elizabeth Brauer ^1,2,4
1. Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON, Canada, K1A 0C6
2. Department of Biology, University of Ottawa, Ottawa, ON, Canada, K1N 9A7
3. Western Crop Innovations, 5030–50 Street, Lacombe, AB T4L 1W8, Canada
4. Microbiology & Plant Pathology Department, University of California Riverside, Riverside, CA, 92521
Corresponding Author: Elizabeth Brauer, ebrauer@ucr.edu

Brauer, Elizabeth

ebrauer@ucr.edu

The Fusarium graminearum fungal pathogen produces the gramillin ionophore during plant host colonization to disrupt the plasma membrane, resulting in ion leakage and suppression of callose defense in the host. Gramillin promotes F. graminearum virulence in sensitive species such as barley and wheat while in insensitive species such as wheat, gramillin has no effect on ion leakage or virulence. Here, we report that gramillin sensitivity varies across maize and barley genotypes and we identify the Lowe barley variety as completely gramillin-insensitive. Gramillin insensitivity is associated with a region on chromosome 5 in two barley populations and can be tracked using KASP markers. Insensitive genotypes have smaller gramillin-induced cellular responses relative to gramillin-sensitive barley genotypes including ion leakage, callose deposition and transcriptional reprogramming. Smaller stress responses aligned with lower expression of fungal virulence genes during infection.

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