Fusarium disease resistance – toxins and feed quality

Fusarium Head Blight (FHB) is a serious disease of all cereal crops and is caused by a spectrum of species. The disease is not only responsible for yield loss but is feared particularly for the production of diverse mycotoxins which cause both acute and chronic disease in livestock and human consumers. This research project ran in the period 2007 to 2011. The aims were to determine:

1. Which mechanisms of resistance operate in barley against Fusarium graminearum infection 
2. How they depend on the protein amount and quality in the grain 
3. How these plant responses influence toxin production by the pathogen
4. How infection and toxin accumulation affects protein quality.

Understanding the interaction between barley and Fusarium will pave the way for development of lasting disease control strategies by determining how resistance can be exploited to limit infection and reduce accumulation of mycotoxins.

The project has led to a body of new knowledge about the nature of causes of FHB under Danish conditions through a combination of field, semi-field and laboratory experiments and analyses. The recent prior development of quantitative real time PCR (q-PCR) methods for the diagnosis of FHB pathogens at Flakkebjerg [1] enabled project scientists to survey both historical and recent cereal samples to determine which species are important in Denmark.

 

An analysis comprising 10 species from the Fusarium complex and 5 important mycotoxins, using q-PCR, mass spectrometry and principal component analysis, revealed major differences in FHB in the five cereals studied as well as great yearly variation [2]. The q-PCR tool also facilitated monitoring fungal biomass during infections, and coupled with the application of reverse genetics and proteomics, facilitated studies on the influence of various factors on levels of infection by the model pathogen F. graminearum, and the response in the host plant tissues [3-6].

 

These studies have variously demonstrated that toxin accumulation closely matches the biomass of F. graminearum in infected tissues, and that plants starved of nitrogen, or stressed by drought or high temperatures are more likely to be infected and therefore accumulate toxins. The studies also demonstrated, using q-RT-PCR to monitor transcripts, that various Fusarium genes encoding secreted proteins are in fact expressed during infection, and that there is active plant defence in the infected tissues. Finally, the global nitrogen regulator, AreA, in F. graminearum was demonstrated to regulate mycotoxin production thereby supporting the results obtained from the nitrogen fertilization and fungal infection studies. Low nitrogen led to a higher infection level of the F. graminearum. As low nitrogen availability activates AreA activity, this would lead to induction of DON biosynthesis and increase the level of mycotoxins. This was also the case for the content of mycotoxins in the barley grains harvested from the cultivation under low Nitrogen regime.

 

The project was funded by The Directorate for Food, Fisheries and Agri Business (now the Danish AgriFish Agency) (6 MKr) and Plant Biotech Denmark (1.2 MKr.) in the period 2006 to 2010.

 

Participants:

Professor David B. Collinge, Department of Plant Biology and Biotechnology, KU-LIFE

Associate Professor Hans Jørgen Lyngs Jørgensen, Department of Plant Biology and Biotechnology, KU-LIFE

PhD student Jens Due Jensen, Department of Plant Biology and Biotechnology, KU-LIFE

 

Vice-dean Henriette Giese, Faculty of Agricultural Sciences, Aarhus University

PhD student Thomas Johansen, Department of Ecology, KU-LIFE

 

Professor Birthe Svensson, DTU

Associate Professor Chris Finnie, DTU

Associate Professor Susanne Jacobsen, DTU

PhD student Fen Yang, DTU

 

Senior Scientist Lise Nistrup Jørgensen, AU-DJF

Senior Scientist Niels Henrik Spliid, AU-DJF

PhD student Linda Kærgaard Nielsen, AU-DJF

 

Short summary in Danish 

 

Reference List

1. Nicolaisen,M., Suproniene,S., Nielsen,L.K., Lazzaro,I., Spliid,N.H., and Justesen,A.F. 2009. Real-time PCR for quantification of eleven individual Fusarium species in cereals. Journal of Microbiological Methods 76: 234-240.
2. Nielsen,L.K., Jensen,J.D., Nielsen,G.C., Jensen,J.E., Spliid,N.H., Thomsen,I.K., Justesen,A.F., Collinge,D.B., and Jørgensen,L.N. 2011. Fusarium Head Blight of Cereals in Denmark: Species Complex and Related Mycotoxins. Phytopathology 101: 960-969.
3. Yang,F., Jensen,J.D., Svensson,B., Jørgensen,H.J.L., Collinge,D.B., and Finnie,C. 2011. Secretomics identifies Fusarium graminearum proteins involved in the interaction with barley and wheat. Mol Plant Pathol DOI: 10.1111/J.1364-3703.2011.00759.X-in press.
4. Jensen,J.D., Hemzalova,V., Frenck,G., Jørgensen,R.B., Strobel,B.W., Collinge,D.B., Jørgensen,H.J.L., and Lyngkjær,M.F. 2010. Sammenhæng mellem klimaændringer og angreb af Fusarium. www.plantekongres.dk,  pp. 390-391.
5. Yang,F., Jensen,J.D., Spliid,N.H., Svensson,B., Jacobsen,S., Jørgensen,L.N., Jørgensen,H.J.L., Collinge,D.B., and Finnie,C. 2010. Investigation of the effect of nitrogen on severity of Fusarium Head Blight in barley. Journal of Proteomics 73: 743-752.
6. Yang,F., Jensen,J.D., Svensson,B., Jørgensen,H.J.L., Collinge,D.B., and Finnie,C. 2010. Analysis of early events in the interaction between Fusarium graminearum  and the susceptible barley (Hordeum vulgare) cultivar Scarlett. Proteomics 10: 3748-3755.