Review Exploring the potential of symbiotic fungal endophytes in cereal disease suppression Karen A. O’Hanlon ⇑ , Kamilla Knorr, Lise Nistrup Jørgensen, Mogens Nicolaisen, Birte Boelt Department of Agroecology, Faculty of Science and Technology, Aarhus University, Denmark highlights " Cereals are an essential source of nutrition for the growing world population. " Cereal production is currently met with many challenges e.g. fungal disease. " Symbiotic fungal endophytes can provide benefits and suppress pathogens in a range of plants. " The current treatment methods for cereal pathogens carry many limitations. " Potential of symbiotic fungal endophytes in biological control of cereal pathogens should be explored. graphical abstract (A) The Neotyphodium coenophialum (Morgan-Jones and W. Gams) Glenn, C.W. Bacon and Hanlin, 1996 syn. Acremonium coenophialum) endophyte is observed as intercellularly elongating hyphae parallel to epidermal cells of the tall fescue (Festuca arundinacea Schreb.) epidermis following analine blue staining (40Â). (B) Analine blue staining of Neotyphodium lolii (Latch, M.J. Chr. and Samuels) Glenn, C.W. Bacon and Hanlin, 1996) from perennial ryegrass (Lolium perenne L.) seeds (10Â). Photographs taken at Aarhus University, Slagelse. article info Article history: Received 18 May 2012 Accepted 27 August 2012 Available online 5 September 2012 Keywords: Fungal endophytes Neotyphodium Cereals C3 cool-season grasses Plant pathogens Pathogen suppression Biological control abstract Cereal crops are an essential source of nutrition worldwide. The incidence and severity of fungal diseases, in particular foliar diseases such as leaf spots, mildews and rusts, is a serious challenge to cereal produc- tion, and this problem is likely to escalate with the changing global climate. Traditional and current methods for controlling fungal pathogens include the use of fungicides, good farming practices, and increasing plant resistance through conventional breeding. While effective, these strategies also carry limitations, mainly due to fungicide-resistance, breakdown of plant resistance, and environmental and health concerns surrounding the use of chemical treatments. There is currently a demand for new disease control strategies, and one such strategy involves the use of symbiotic fungal endophytes as biological control agents against fungal pathogens in cereals. Despite the fact that biological control by symbiotic fungal endophytes has been documented, particularly with respect to clavicipitaceous endophytes in C3 cool-season grasses, this area remains relatively underexplored in cereals. We highlight for the first time the potential in using symbiotic fungal endophytes to control foliar cereal diseases, and we discuss important considerations surrounding this. Ó 2012 Elsevier Inc. All rights reserved. 1. Cereals – their importance and challenges by fungal diseases Cereals constitute an extremely important source of human and animal nutrition worldwide, collectively representing approxi- mately 56% and 44% of the worlds human and animal energy con- sumption, respectively (http://www.fao.org). The need to meet global food demands for the predicted growing world population of nine billion by 2050 requires improvements in cereal crop pro- duction per unit of land (Godfray et al., 2010). The demand for cereals is projected to reach three billion tons by 2050, and it is projected that annual cereal production will have to grow by al- most one billion tons (2.1 billion tons today) (http://www.fao.org). 1049-9644/$ - see front matter Ó 2012 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.biocontrol.2012.08.007 ⇑ Corresponding author. Address: Department of Agroecology, Faculty of Science and Technology, Aarhus University, Forsøgsvej 1, Slagelse 4200, Denmark. Fax: +45 8715 6000. E-mail address: Karen.ohanlon@agrsci.dk (K.A. O’Hanlon). Biological Control 63 (2012) 69–78 Contents lists available at SciVerse ScienceDirect Biological Control journal homepage: www.elsevier.com/locate/ybcon