Besides improved mineral nutrition, plants colonised by arbuscular mycorrhizal (AM) fungi often display increased biomass and higher tolerance to biotic and abiotic stresses. Notwithstanding the global importance of wheat as an agricultural crop, its response to AM symbiosis has been poorly investigated. We focused on the role of an AM fungus on mineral nutrition of wheat, and on its potential protective effect against Xanthomonas translucens. To address these issues, phenotypical, molecular and metabolomic approaches were combined. Morphological observations highlighted that AM wheat plants displayed an increased biomass and grain yield, as well as a reduction in lesion area following pathogen infection. To elucidate the molecular mechanisms underlying the mycorrhizal phenotype, we investigated changes of transcripts and proteins in roots and leaves during the double (wheat-AM fungus) and tripartite (wheat-AM fungus-pathogen) interaction. Transcriptomic and proteomic profiling identified the main pathways involved in enhancing plant biomass, mineral nutrition and in promoting the bio-protective effect against the leaf pathogen. Mineral and amino acid contents in roots, leaves and seeds, and protein oxidation profiles in leaves, supported the omics data, providing new insight into the mechanisms exerted by AM symbiosis to confer stronger productivity and enhanced resistance to X. translucens in wheat.

The aim of this study was to examine the effect of five naturally occurring compounds from essential oils on 10 different species of mycotoxigenic fungi involved in several plant diseases. The antifungal activities of terpinen-4-ol, eugenol, carvone, 1,8-cineole (eucalyptol) and thymol were observed in vitro on Fusarium subglutinans, Fusarium cerealis, Fusarium verticillioides, Fusarium proliferatum, Fusarium oxysporum, Fusarium sporotrichioides, Aspergillus tubingensis, Aspergillus carbonarius, Alternaria alternata and Penicillium sp. The naturally occurring compounds tested showed toxic effects on in vitro mycelium growth of all fungal species but with different level of potency. The results are encouraging for further investigations of in planta antifungal activities of these essential oils components.