Institute of Agricultural Sciences - CSIC, Spain
Title: Strategies to improve tolerance to abiotic stress in legumes
Biography: Jose J Pueyo
Legumes play a key role in sustainable agriculture. Mineral nitrogen deficiency is an important limiting factor for plant growth in arid and semi-arid regions, and rhizobia-legume symbioses are the primary source of fixed nitrogen in such areas. The introduction of legumes and their nodulating rhizobia may have an important effect on the reclamation of degraded, polluted, saline, marginal soils for sustainable agriculture. Such recovery is becoming an urgent matter due to climate change, the increasing extension of salinized land and the ever-rising requirements for food and feed. In general, both rhizobia and legumes have a low or moderate tolerance to abiotic stress. Moreover, symbiosis and nodule functions are very sensitive to abiotic stress, more so than the host legume or the rhizobia. Thus, it is of interest to obtain bacterial inocula and legume varieties with enhanced tolerance to abiotic stress for use in soil reclamation, which can be achieved by traditional trait selection or by biotechnological procedures. We will present our results on the selection of tolerant legume cultivars and rhizobial strains, as well as our biotechnological approaches to obtain legumes and rhizobia with improved tolerance to abiotic stress. Omics analyses and genome-wide association studies (GWAS) appear as optimal tools for elucidating the physiological and molecular mechanisms that determine sensitivity or tolerance to abiotic stress in the symbiotic system, which might help define strategies to obtain nodulated legumes with enhanced tolerance to environmental stresses that act efficiently in reclaiming and exploiting marginal soils.