EFS12- Book of abstracts - Contact
EFS12- Book of abstracts - Contact
EFS12- Book of abstracts - Contact
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SESSION 3: PATHOGENESIS – EPIDEMIOLOGY AND POPULATION<br />
GENETICS<br />
Insights into the Fusarium-wheat root pathosystem<br />
uncover a hidden danger to wheat production<br />
Q. Wang, A. Furch, S. Buxa, A. Römpp, D. R. Bhandari, W. Friedt, S.<br />
Gottwald<br />
Department <strong>of</strong> Plant Breeding, Justus-Liebig University Giessen, Heinrich-Buff-Ring 26, 35392<br />
Giessen, Germany<br />
E-mail: sven.gottwald@agrar.uni-giessen.de<br />
While the floral Fusarium disease FHB relies on successful spike colonization,<br />
soil- but also seed-borne diseases rely on successful colonization <strong>of</strong> roots which<br />
provide an excellent nutrient supply. Roots are the ʻplant hidden halfʼ and their<br />
diseases are <strong>of</strong>ten unseen, misdiagnosed and challenge disease assessments.<br />
We are investigating root rot (FRR) as a model for Fusarium-wheat root<br />
interactions which still represent a knowledge gap regarding epidemiology,<br />
pathogenesis, and the genetics <strong>of</strong> wheat resistance.<br />
Our current investigations on a diverse set <strong>of</strong> wheats have demonstrated the high<br />
capability <strong>of</strong> F. graminearum to infect and colonize wheat roots - followed by its<br />
spread into distal plant tissue. Studies on the mode <strong>of</strong> FRR disease revealed a<br />
four-phase colonization strategy similar to other Fusarium diseases. Unique<br />
confocal microscopic analyses on F. graminearum root colonization exhibit a<br />
devastating invasion <strong>of</strong> all cell types. Stems and leaves were preferentially<br />
colonised via the vascular system. In addition, mass spectrometry imaging has<br />
been established as new technology for the metabolic pr<strong>of</strong>iling <strong>of</strong> infested/noninfested<br />
root, stem and leaf tissues. Finally, diminished water/nutrient supply,<br />
intracellular hyphae growth and fungal toxins seem to be essential damaging<br />
factors at seedling and adult stage. Hence, reduced seedling vigour, impaired<br />
plant development and prematurity blight <strong>of</strong> side shoots/heads were identified as<br />
major threats to yield.<br />
Generally, inverse reactions to Fusarium infestation seem to be present between<br />
root and spike. The major FHB resistances failed to protect wheat plants against<br />
FRR, while a partial resistance to root colonization was found for FHB susceptible<br />
genotypes. Accordingly, three well-known FHB/DON resistance genes were<br />
Fusarium-induced associated with low FRR infestations, thereby revealing an<br />
activity contrary to FHB treated spikes. Hence, current FHB resistant cultivars are<br />
probably insufficient to prevent root colonization and to meet challenges<br />
represented by present and future soil pathogen accumulations associated with<br />
intensive agriculture.<br />
Keywords: F. graminearum-wheat root interactions, root rot, pathogenesis,<br />
histopathology<br />
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