Biotechnology for Sustainability: Nanobiotechnological Approaches to Improve Plant Resilience

Agriculture is severely suffering due to the escalating incidence of abiotic stresses, exacerbated by global warming, which has been leading to reduced agricultural yields and extensive economic losses. Despite its longstanding presence over the centuries, salinity pollution is a very current issue that has not been solved and still endangers agricultural productivity worldwide, threatening food supply and human well-being. Nano-biotechnology offers promising and eco-friendly solutions that can support the transition to a more sustainable and resilient agri-food system. Microbial-based biostimulants can be based on the use of plant growth-promoting rhizobacteria (PGPR) as single species or as microbial consortia (MCs). In either case, traceability procedures are required to improve their performance in field trials. To assess the shelf life of PGPR inoculated into the soil is important to determine which elements contribute to their effectiveness and their interactions with plants and indigenous soil microbiota. The present work developed a real-time PCR (qtPCR) method to specifically detect and quantify bacteria when added as a microbial consortium to agricultural soils. It has been proved that three species of the microbial consortium (B. ambifaria, B. amyloliquefaciens and R. aquatilis) administered to wheat plants with biochar and the mycorrhizal fungus Rhizophagus intraradices successfully colonized the wheat rhizosphere. The results also showed biochar had a positive effect on PGPR growth. The research work also focused on investigating the interaction between microbial-based products and nanomaterials in counteracting abiotic stresses. Silica and chitosan-tripolyphosphate nanoparticles were tested in association with a commercial microbial-based product on soybean (Glycine max L.) and cherry tomato (Solanum lycopersicum L.) plants grown in the greenhouse. The results proved that the coupled nano-biotechnological approaches have been effective in enhancing plant health and development under salt stress conditions, by restoring photosynthetic activity, favoring nutrients uptake and limiting sodium accumulation into the roots.