Identification of conserved and new miRNAs that affect nodulation and strain selectivity in the Phaseolus vulgaris?Rhizobium etli symbiosis through differential analysis of host small RNAs?

CASTAINGTS, MELISSE; KIROLINKO CRISTINA; RIVERO, CLAUDIO; ARTUNIAN JENNIFER; MANCINI VILLAGRA ULISES; BLANCO FLAVIO; ZANETTI MARIA EUGENIA

NEW PHYTOLOGIST

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2022

0028-646X

Phaseolus vulgaris plants from the Mesoamerican centre of genetic diversification establisha preferential and more efficient root nodule symbiosis with sympatric Rhizobium etli strains.This is mediated by changes in host gene expression, which might occur either at the transcriptionalor at the post-transcriptional level. However, the implication of small RNA (sRNA)-mediated control of gene expression in strain selectivity has remained elusive. sRNA sequencing was used to identify host microRNAs (miRNAs) differentially regulated inroots at an early stage of the symbiotic interaction, which were further characterized byapplying a reverse genetic approach. In silico analysis identified known and new miRNAs that accumulated to a greater extent inthe preferential and more efficient interaction. One of them, designated as Pvu-miR5924,participates in the mechanisms that determine the selection of R. etli strains that will colonizethe nodules. In addition, the functional analysis of Pvu-miR390b verified that this miRNA is anegative modulator of nodule formation and bacterial infection. This study not only extended the list of miRNAs identified in P. vulgaris but also enabled theidentification of miRNAs that play relevant functions in nodule formation, rhizobial infectionand the selection of the rhizobial strains that will occupy the nodule.