Health-Promoting Properties of Plant Products: The Role of Mycorrhizal Fungi and Associated Bacteria

The concept of food quality, traditionally based on nutritional and sensory properties, hasrecently acquired an additional meaning, referring to the health-promoting properties of plantproducts, that are ascribed to plant secondary metabolites called phytochemicals, primarilyrepresented by polyphenolic compounds and glucosinolates. The diversity and content ofphytochemicals in plant products are affected by different variables, such as plant genotype,agronomic factors, and arbuscular mycorrhizal fungi (AMF), which establish mycorrhizalsymbioses with most crops, including cereals, legumes, vegetables, fruit trees, sunflower, cotton,and sugarcane. AMF and associated bacteria enhance plant growth and health, and affect theproduction of polyphenols and carotenoids, and the activity of antioxidant enzymes. Theproduction of health-promoting phytochemicals was shown to be differentially modulated bydifferent AMF isolates and bacterial strains, in several food plants, i.e., tomato, lettuce, strawberry,artichoke, maize, grapevine, sunflower. Here, we provide an overview of recent studies concerningthe multiple roles played by AMF and associated bacteria in the modulation of the biosynthesis ofplant secondary metabolites with health-promoting activity, and discuss the development ofdesigned multifunctional consortia to be used in sustainable agriculture.