Transcriptomic analysis of Mesoamerican and Andean Phaseolus vulgaris accessions revealed mRNAs and lncRNAs associated with strain selectivity during symbiosis

CLÚA, JOAQUÍN; RIVERO, CLAUDIO; RODA C; DONA SOLEDAD; ZANETTI MARIA EUGENIA; BLANCO FLAVIO}

Scientific Reports

Nature Portfolio

Lugar: Nueva York; Año: 2022 vol. 12

2045-2322

Legume plants establish a nitrogen-fixing symbiosis with soil bacteria known as rhizobia.Compatibility between legumes and rhizobia is determined at species-specific level, but variations inthe outcome of the symbiotic process are also influenced by the capacity of the plant to discriminateand select specific strains that are better partners. We compared the transcriptional response oftwo genetically diverse accessions of Phaseolus vulgaris from Mesoamerica and South Andes toRhizobium etli strains that exhibit variable degrees of symbiotic affinities. Our results indicate thatthe plant genotype is the major determinant of the transcriptional reprogramming occurring inroots at early stages of the symbiotic interaction. Differentially expressed genes (DEGs) regulated inthe Mesoamerican and the Andean accessions in response to specific strains are different, but theybelong to the same functional categories. The common and strain-specific transcriptional responsesto rhizobia involve distinct transcription factors and cis-elements present in the promoters of DEGsin each accession, showing that diversification and domestication of common bean at differentgeographic regions influenced the evolution of symbiosis differently in each genetic pool. QuantitativePCR analysis validated our transcriptional datasets, which constitute a valuable source of coding andnon-coding candidate genes to further unravel the molecular determinants governing the mechanismsby which plants select bacterial strains that produce a better symbiotic outcome