1. Nitrogen fixing endosymbiotic bacteria : old chaps and new findings / M.H. Ramr̕ez-Bahena ... [et al.] -- 2. Biodiversity of slow-growing rhizobia : the genus bradyrhizobium / D. Durǹ ... [et al.] -- 3. Importance of motile and biofilm lifestyles of rhizobia for the establishment of symbiosis with legumes / J. Nogales ... [et al.] -- 4. Nod factor production and abiotic stress in rhizobium / B. Guasch-Vidal ... [et al.] -- 5. Strategies of salt tolerance in the rhizobia-legume symbiosis / M. Lp̤ez-Gm̤ez, F. Palma and C. Lluch -- 6. Mineral nutrition in the legume-rhizobia nitrogen fixing symbiosis / I. Abreu ... [et al.] -- 7. Metal transport in the rhizobium-legume symbiosis / M. Gonzl̀ez-Guerrero ... [et al.] -- 8. Ecology of denitrification in soils and plant-associated bacteria / E.J. Bedmar ... [et al.] -- 9. Bacterial protein secretion systems : implications in beneficial associations with plants / I. Jimňez-Guerrero ... [et al.] -- 10. Nodular endophytes : an untapped diversity / E. Velz̀quez ... [et al.] -- 11. Azospirillum-plant interaction : from root colonization to plant growth promotion / F. Wisniewski-Dy ̌... [et al.] -- 12. Biocontrol of fungal root pathogens by fluorescent pseudomonas / M. Sǹchez-Contreras ... [et al.] -- 13. Inoculants based in autochthonous microorganisms, a strategy to optimize agronomic performance of biofertilizers / D. Mulas ... [et al.] -- 14. Engineering the rhizosphere of legumes for improved bioremediation / E. Pajuelo ... [et al.] -- 15. Arbuscular mycorrhizas and their significance in promoting soil-plant system sustainability against environmental stresses / J.M. Barea ... [et al.] -- 16. Can arbuscular micorrhizal fungi (AMF) be effective tools for improving the nutritional quality of crops? Findings from a worldwide consumed vegetable : lettuce / M. Baslam ... [et al.] -- 17. Ectomycorrhizal plants : methods, applications and certification / P. Alvarado, M. Honrubian and J.L. Manjn̤ -- 18. Metagenomics of plant-microorganism interaction : source of novel recombiant genes for biotechnological applications / A. Garca̕-Villaraco ... [et al.].