PRIN Project Microbionet

STUDY ON SYNERGISTIC INTERACTIONS BETWEEN BENEFICIAL BACTERIA AND FUNGI TO DEVELOP NEW MICROBIAL-BASED FORMULATIONS FOR SUSTAINABLE PLANT PROTECTION (Acronym: MICROBIONET)

PROJECT DESCRIPTION

Plant roots provide a complex mixture of nutrients by root exudation allowing the creation of stably associated microbial communities of which a relevant part is represented by the bacteria that interact with the host plant both as epiphytic and endophytic. The bacterial community composition significantly changes between the bulk soil, rhizosphere, and the endophytic environment; however, its composition can be affected by many other factors (e.g., environment and host genotype). The roots associated microbiome can be also affected by other soil-borne microorganisms that directly or indirectly interact with the plants. In our opinion, fungi represent an interesting means to bacterial conveying in the soil driving the colonization of plant roots. Indeed, the mycelial network creates connections and way, allowing a fast movement of bacteria into the soil. Furthermore, the bacteriome and its composition affect different aspects of plant health (disease resistance, stress tolerance, and nutrient acquisition). Our project proposal, by using a well-studied and easy-to-use pathosystem in laboratory and greenhouse conditions (i.e., Fusarium oxysporum f.sp. lycopersici-tomato plant) and beneficial microorganisms, aims to in-depth understand the dynamics in the roots associated with bacterial communities to develop sustainable strategies for crop management. In a preliminary part of our project, we will study the effect on tomato root-associated bacterial community of fungi colonization mediated by both beneficial (i.e., Trichoderma afroharzianum) and pathogenic (i.e., Fusarium oxysporum), highlighting any differences between a protective or pathogenic interactions. For this purpose, NGS techniques will be applied to monitor the bacterial community in tomato rhizosphere of plants subjected to the experimental treatments. Contextually, tomato root-associated bacteria will be isolated from Trichoderma treatments and this microbial collection will be characterized by evaluating phenotypes related to plant growth promotion and protection. After that, the most promising bacterial isolates will be characterized evaluating their ability to closely interact with Trichoderma, and the possibility to be displaced in the soil by the mycelial network. The selected bacterial isolates will be used to develop a microbial consortium with Trichoderma afroharzianum applied as soil inoculant to evaluate the effectiveness in preventing tomato Fusarium wilt and as growth biostimulant. The bacteria making up the more effective microbial consortia will be subjected to molecular characterization by genome sequestration and considered for future patent protection and formulations development. The new bioformulates based on microbial consortia that will be developed by the present project will represent a valid tool for the sustainable management of root diseases in horticultural crops, reducing the severe losses due to soil-borne pathogens ad the use of synthetic fungicides.