Detalle de: White lupin and its associated bacteria as a heavy metal phytoremediation tool with environmental and agronomic added value (LUPIMETAL)

Contamination of agricultural soils by heavy metals has become a prime concern for today's society, as it entails serious environmental risks, feed and food security issues, and a threat to animal and human health, as plants constitute the main source for heavy metal entry into the food chain. White lupin (Lupinus albus) is a legume protein crop that establishes symbiosis with soil bacteria capable of nitrogen fixation. It also develops cluster roots, which are root structures with hundreds of short rootlets that greatly increase the root surface in contact with the rhizosphere, and exude significant amounts of organic acids, phenolics and other compounds that solubilize soil organic P, mobilize Fe and other nutrients and immobilize toxic heavy metals, thus allowing growth in nutrient-poor and polluted soils. Previous results from our group have proven that white lupin has a potential use in phytoremediation as a phytoimmobilizer plant by rhizosequestration of heavy metals, and cluster roots act as metal hyperaccumulators. The present proposal, LUPIMETAL, aims to advance our understanding in an integrated way through a multifaceted analysis of the plant and its associated bacteria as a heavy metal remediation tool. Identifying heavy metal-tolerant lupin cultivars that display abundant cluster root formation will be achieved through germplasm screening of at least 300 accessions. Tolerant and efficient symbiotic rhizobia from polluted soils will also be selected. The whole system will be analyzed from different perspectives, with diverse tools to understand mechanisms, identify genes, proteins and metabolites involved in the plant tolerance, uptake, accumulation, detoxification and immobilization of heavy metals with the final aim of engineering a perfect bioremediation ensemble to be used in the recovery of polluted soils and the restoration of agroecosystems, contributing to the reduction of environmental and food- and feed-associated health risks. The expected results will contribute to the Spanish and European societal challenges of combating soil contamination and landscape degradation, and ultimately to the environmentally-conscious development of a sustainable agriculture aimed to ensure global food security.