**4. Cereal secondary metabolites with antifungal activity**

A component of the plant resistance to *Fusarium* and their toxins is related to the capacity of plant tissues to reduce the fungal infestation and mycotoxin accumulation (e.g. zearalenone, type B trichothecenes, fumonisins) throughout the presence of secondary metabolites. Secondary metabolites are compounds produced by plants for which no role has yet been found in growth, photosynthesis, reproduction or other "primary" functions; however, it has been found that they are implicated in plant defense. The presence of secondary metabolites along with temperature, water activity, pH and nutrients have been identified as key features regulating *Fusarium* and their mycotoxins [29].

Plant endogenous compounds can be both constitutively synthesized and induced in response to pathogen infection. Recent metabolomic studies have pointed an important amount of cereal metabolites produced by cereals such as fatty acids, amino acids and their derivatives, carbohydrates, amines and polyamines, terpenoids, benzoxazinoid derivatives and phenylpropanoids that contribute to the resistance of *Fusarium* and low mycotoxin accumulation (**Figure 2**). These metabolites are derived from primary and secondary metabolism [30]. Based on their biosynthetic origins, plant secondary metabolites can be divided into three major groups: phenylpropanoids, terpenoids and nitrogen-containing alkaloids. The secondary metabolites that play a role in the plant resistance to *Fusarium* and mycotoxin accumulation are listed below.
