Format: ORAL

Bernardo Duarte1,2, Joo Carreiras1, Ana Cruz-Silva3, Bruno Fonseca1,3, Ricardo C. Carvalho1, Enrique Mateos-Naranjo4, Ignacio D. Rodrguez-Llorente5, Elosa Pajuelo5, Susana Redondo-Gmez4, Isabel Caador, Ana Rita Matos2,3, Jennifer Mesa Marin4, Andreia Figueiredo2,3

1 MARE—Marine and Environmental Sciences Centre & ARNET – Aquatic Research Network Associated Laboratory, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisbon. 2 Departamento de Biologia Vegetal, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal.3 3 BioISI—Biosystems and Integrative Sciences Institute, Departamento de Biologia Vegetal, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal. 4 Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain. 6 Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.

The world population is expected to reach 9.1 billion by 2050, thus raising the need for increasing global food production by 70% to match the growing demand. Alongside, the impacts of global climate change tend to reduce land fertility at a rate higher than the adaptation capacity of agricultural practices, imposing new challenges to agriculture, increasing physiological constrain factors (high atmospheric CO2, drought, salinization, thermal stress). Thus, the need to search for alternative cash crops and nature-based solutions and practices towards sustainable and regenerative cultivation schemes arises. Recently several bacterial isolates have been identified from marine ecosystems with plant growth-promoting abilities displaying highly promising results upon application in crop cultivation, allowing plants to fight back physiological constraints. Plant rhizosphere bioaugmentation with marine plant growth-promoting bacteria (PGPB) appears as a reliable, low-cost nature-based solution to improve agriculture production under disadvantageous conditions. Among the available PGPB hosts, halophyte plants with recognized nutritional and agroecological value but also a high degree of tolerance to several physiological constraints such as soil salinization, drought, CO2 rising, and disadvantageous thermal conditions. Nevertheless, despite this high tolerance degree to adverse environments, in common garden experiments, these species still suffer some biomass production decrease under extreme conditions. Thus, these species thriving ability in natural ecosystems indicates that this is not only boosted by their intrinsic tolerance but also by the presence of key microorganisms that improve these tolerance and resistance traits, becoming an attractive environment for PGPB bioprospection. In the present work, we present and discuss the application of marine PGPB isolated in different classical and novel crop systems as biotools to improve plants resistance and tolerance mechanisms to adverse cultivation conditions (for e.g. heat, drought and saline stress) as well as potential tools to study the underlying physiological mechanisms improved by this rhizosphere bioengineering.