Affiliation:
1. Department of Soil. Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, 28006 Madrid, Spain
2. Laboratory of Biodiversity and Valorization of Arid Areas Bioresources, BVBAA, Faculty of Sciences, University of Gabès, Erriadh, Zrig, Gabès 6072, Tunisia
Abstract
Lupin is a high-protein legume crop that grows in a wide range of edaphoclimatic conditions where other crops are not viable. Its unique seed nutrient profile can promote health benefits, and it has been proposed as a phytoremediation plant. Most rhizobia nodulating Lupinus species belong to the genus Bradyrhizobium, comprising strains that are phylogenetically related to B. cytisi, B. hipponenese, B. rifense, B. iriomotense/B. stylosanthis, B. diazoefficiens, B. japonicum, B. canariense/B. lupini, and B. retamae/B. valentinum. Lupins are also nodulated by fast-growing bacteria within the genera Microvirga, Ochrobactrum, Devosia, Phyllobacterium, Agrobacterium, Rhizobium, and Neorhizobium. Phylogenetic analyses of the nod and nif genes, involved in microbial colonization and symbiotic nitrogen fixation, respectively, suggest that fast-growing lupin-nodulating bacteria have acquired their symbiotic genes from rhizobial genera other than Bradyrhizobium. Horizontal transfer represents a key mechanism allowing lupin to form symbioses with bacteria that were previously considered as non-symbiotic or unable to nodulate lupin, which might favor lupin’s adaptation to specific habitats. The characterization of yet-unstudied Lupinus species, including microsymbiont whole genome analyses, will most likely expand and modify the current lupin microsymbiont taxonomy, and provide additional knowledge that might help to further increase lupin’s adaptability to marginal soils and climates.
Funder
Ministry of High Education and Scientific Research, Tunisia, the Agencia Estatal de Investigación, AEI, Spain
Agencia Estatal Consejo Superior de Investigaciones Científicas, CSIC, Spain
Subject
Inorganic Chemistry,Organic Chemistry,Physical and Theoretical Chemistry,Computer Science Applications,Spectroscopy,Molecular Biology,General Medicine,Catalysis