Small RNA involved in the preferential symbiotic association between Phaseolus vulgaris and Rhizobium etli.

CASTAINGTS, MELISSE; DALLA VIA, VIRGINIA; AGUILAR, O. MARIO; BLANCO, FLAVIO; ZANETTI, MARÍA EUGENIA

Mar del Plata

Congreso; . XV Congreso Latinoamericano XXX Reunión Argentina de Fisiología Vegetal.; 2014

Common bean (Phaseolus vulgaris) establishes a symbiotic interaction with Rhizobium etli, resulting in the formation of root nitrogen-fixing nodules. Interestingly, beans from the Mesoamerican center of genetic diversification are able to discriminate different strain of R. etli which are more efficient in the nodulation process.  Our group has identified several protein-coding genes involved in this preferential interaction. Recently, we focused our studies on the identification of small RNAs (sRNAs), including both microRNAs (miRNAs) and small interference RNAs (siRNAs), that might participate in the strain preference observed in Mesoamerican beans. We generated sRNAs libraries from non-inoculated roots or from roots inoculated with strains of R. etli with different nodulation efficiency. Sequencing of the libraries using Illumina technology (1x50bp) yielded an average of 28 millions reads per library with primary lengths of 21 and 24 nucleotides. Reads were mapped to the P. vulgaris reference genome, revealing that most of them mapped to intergenic regions. We are analyzing changes in sRNAs abundance in each tested condition by using bioinformatics tools. This approach will allow us to identify and select new sRNAs with potential roles in this preferentially symbiosis, which will be further characterized by  functional genetic.