Corso di Laurea Magistrale in Biotecnologie vegetali - BV

Legumes develop two beneficial symbioses with soil microbes: symbiotic nitrogen fixation (SNF) with rhizobiacean bacteria and arbuscular mycorrhizas (AM) with glomeromycete fungi. This dual symbiotic aptitude raises great interest in staple crops such as soybean for the sustainability of agroecosystems and food security strategies in line with the EU green deal program.
AM fungi enhance host plant absorption of water and mineral nutrients, especially P and N; SNF feeds plants with NH3 from fixed atmospheric N2. Even if both symbioses allow a major and environment-friendly reduction in fertilizer input, plant symbiotic aptitudes have not always been favored by breeders.

We have recently demonstrated that short-chain chito-oligosaccharides (COs), the signalling molecules released by AM fungi, efficiently promote AM development and biomass production in both laboratory (Medicago truncatula: Volpe et al., 2020) and field conditions (mix of legume and non-legume fodder plants: AMFORQuality project), leading the way to the application of COs as AM stimulants in agriculture. Preliminary observations suggest that CO treatment may also stimulate legume SNF. In fact, COs could serve as substrates for Nod factor biosynthesis by rhizobia.

Importantly, COs are completely bio-degradable compounds, commonly found in soil and considered safe for the environment (Sharp, 2013).
Furthermore, we have recently shown that COs can be obtained from the processing of filamentous fungal biomass grown on food industry by-products (Crosino et al., 2021).

In this context, CIRCLES outlines a virtuous waste-to-resource cycle by exploiting agricultural waste materials from soybean harvest as substrates for the growth of fungal biomass, which is then used for the production of purified COs in an authentic circular economy framework.
Each main goal of CIRCLES represents a breakthrough study: clarifying how COs enhance AM and SNF; shedding light on their beneficial effects on plant nutrition and balance legume crop agroecosystem; developing a circular economy system for CO production and use.

CIRCLES results will pave the way for a fruitful transfer of information from model to crop plants: our analyses on the model legume Lotus japonicus will be extended to Medicago truncatula for specific investigations, while Glycine max (soybean) will be used to transfer our results to the field and pre-applicative greenhouse trials with a high-performing phenotyping platform (Agenzia Lucana di Sviluppo e di Innovazione in Agricoltura, ALSIA).

CIRCLES will apply a novel protocol for low-cost CO production from vegetable waste products; investigate the balance between AM and SNF under CO treatment; its impact on plant signaling and gene expression; the crosstalk between CO treatments and nutrient transport and assimilation (N and P); and validate the results in field conditions on the staple crop soybean.