Plant stress and mycotoxin accumulation in maize D. FERRIGO, A. RAIOLA, R. CAUSIN * Dipartimento Territorio e Sistemi Agro-forestali (TESAF), Università di Padova, Agripolis, Viale dell’Università 16, 35020 Legnaro (PD), Italy Keywords: heat-wave, maize, mycotoxins, oxidative stress, stress factors. Summary. – The 2012 crop year in north-east Italy was characterized by a strong heat-wave event, and areas influenced by this environmental condition presented an anomalous accumulation of mycotoxins in maize. Mycotoxins are secondary metabo- lites, harmful to human and animals, produced by pathogenic fungi that contaminate foodstuffs. Plants suffering by stress are characterized by lower crop yield and quality, increased fungal infection and in some cases by higher amounts of mycotoxins. In plant, heat-wave events and generally stress factors afflict physiological traits and are associ- ated with oxidative stress. Since oxidative stress is fundamental also for activation of mycotoxin biosynthesis in fungi, stress conditions in plant and mycotoxin accumulation are often correlated. The present paper aims to report the influence of some stress factors in relation to mycotoxin accumulation providing further data to comprehension of stress management with particular emphasis to heat-wave related events. Introduction. – Mycotoxins are secondary metabolites produced by some fungal species that colonize crops. Mycotoxin contamination of foodstuffs is a worldwide problem and a major health threat for humans and animals that cause significant economic losses. In Italy, cereals (maize and wheat) are the most important agricultural commodities that can be contaminated by mycotoxins and the main effective way to reduce their quantity in crop is hindering its development during crop production and in post-harvest. Maize colonization by toxigenic fungi derives from multiple pathways as endophytism, soil inoculum, insect lesions, silk colonization; however, it is worth to note that, when all the possible infection pathways act, the mycotoxin content is higher than the sum of the production provided by each single infection pathway, as reported for Fusarium verticillioides infection and fumonisin accumula- tion (Causin et al., 2009). A non-additive effect seems to be involved and other factors as environmental conditions and agricultural practices could play an important role in mycotoxin occurrence and modulation. The ways to reduce fungal infection and mycotoxin contamination include the respect of good agricultural practices (GAPs) (Blandino et Agrochimica, Vol. LVIII – Special Issue (2014) 116-127 * Corresponding author: roberto.causin@unipd.it