EFS12- Book of abstracts - Contact
EFS12- Book of abstracts - Contact
EFS12- Book of abstracts - Contact
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
SESSION 1: FUSARIUM – GENETICS, GENOMICS AND SYSTEMS BIOLOGY<br />
P7 - FCSTUA controls pathogenicity and morphophysiological<br />
traits in Fusarium culmorum<br />
F. Spanu 1* , M. Pasquali 2* , B. Scherm 1 , V. Balmas 1 , L. H<strong>of</strong>fman 2 , K. Hammond-<br />
Kosack 3 , M. Beyer 2 , Q. Migheli 1<br />
1 Dipartimento di Agraria - Plant Pathology and Entomology Unit and Unità di ricerca Istituto Nazionale<br />
di Biostrutture e Biosistemi, Università degli Studi di Sassari, Via E. De Nicola 9, I-07100 Sassari, Italy;<br />
2 CRP - Gabriel Lippmann, 41, rue du Brill, L-4422 Belvaux, Luxembourg; 3 Wheat Pathogenomics<br />
Programme, Plant Pathology and Microbiology Department, Rothamsted Research, Harpenden, Herts<br />
AL5 2JQ, UK<br />
E-mail: fspanu@uniss.it<br />
*The first two authors have equally contributed to the present work.<br />
Fusarium culmorum is one <strong>of</strong> the most harmful causal agents <strong>of</strong> the crown and<br />
foot root (CFR) and the Fusarium head blight (FBH) diseases on durum wheat.<br />
Here we identified and characterised the main function <strong>of</strong> FcstuA gene, an<br />
APSES protein having 99% homology to the FgstuA protein, in the biological<br />
cycle <strong>of</strong> F. culmorum. Two wild-type strains, FcUK99 (a deoxynivalenol producer)<br />
and Fc233B (unable to produce toxin in vitro) were used to FcstuA deletion by<br />
homologous recombination. The functional analysis <strong>of</strong> deletion mutants obtained<br />
from both wild-type strains showed that FcStuA mutants displayed lack <strong>of</strong><br />
monophialides and decreased germination efficiency <strong>of</strong> conidia, stunted<br />
vegetative growth, altered pigmentation on solid substrates, and loss<br />
hydrophobicity <strong>of</strong> the mycelium. Glycolytic process efficiency was strongly<br />
impaired and growth was partially restored on glutamic acid. Growth on pectin-like<br />
sources ranked in between glucose and glutamic acid with the following order (the<br />
lowest to the highest growth): beechwood xylan, sugarbeet arabinan,<br />
polygalacturonic acid, citrus pectin, apple pectin, potato azogalactan. DON<br />
production in the mutants originating from FcUK99 strain was significantly<br />
decreased (- 95%) in vitro. Furthermore, Fcstua was shown to play an important<br />
role in pathogenicity, as ΔFcstuaA mutants underwent complete loss <strong>of</strong><br />
pathogenicity in both CFR and FHB pathosystems on durum wheat and were<br />
unable to colonise different plant tissues (apple, potato and tomato). No<br />
differences between mutants, ectopic and wild-type strains were observed<br />
concerning the level <strong>of</strong> resistance towards four fungicides belonging to three<br />
classes, the demethylase inhibitors epoxiconazole and tebuconzole, the succinate<br />
dehydrogenase inhibitor isopyrazam and the cytochrome bc1 inhibitor<br />
trifloxystrobin. StuA, given its multiple functions in cell regulation and<br />
pathogenicity control, is proposed as a potential target for novel disease<br />
management strategies.<br />
Keywords: durum wheat, trichothecenes, polygalacturonase, fungicide resistance,<br />
APSES proteins<br />
99