Molecular bases of strain-specific responses of Phaseolus vulgaris roots to symbiotic bacteria with different efficiency in nitrogen-fixing symbiosis

Some legume plants can establish a nitrogen-fixing symbiosis with rhizobia. Compatibilty between rhizobia and legumes is determined at species-specific level, but there are variations on the efficiency of the process determined by the capacity of the plant to select specific strains that are better partners in terms of the biological outcome. In this work we used a model system based in the coevolution of two genetic pools of common bean (Phaseolus vulgaris) with strains of R. etli that establish a more efficient interaction to study the transcriptional changes occurring in roots at an early time of the interaction. Phaseolus vulgaris roots of NAG12 and ALUBIA accessions were inoculated with Yeast Extract Mannitol media as a control (CTL), or the following R. etli strains: SC15, CE3, 55N1 and 124N1. Root tissue samples were collected 24 hours post inoculation.