Pervasive regulation of RNA metabolism enhances root colonization of nitrogen-fixing symbiotic α-rhizobia

The rhizosphere and root surface are nutrient-rich but selective for rhizosphere microorganisms

Here, we decipher a post-transcriptional network regulated by homologous genestrans- Small RNAs (sRNAs) AbcR1 and AbcR2, metabolism of recombinant nitrogen-fixing alpha rhizobiumPhytophthora rhizobiumSymbiosis with the legume host alfalfa in the pre-infestation stage

Nitrogen-fixing nodule symbionts between rhizobia and legumes provide more than half of the bound nitrogen for terrestrial ecosystems each year, allowing plant growth to be independent of environmentally unfriendly fertilizers

1) These interacting species-specific plant-microbe interactions rely on rigorous metabolic cooperation between partners

Phytophthora rhizobiumAlfalfa Symbiote (alfalfafifty, ) and other legumes (11–13) transcriptome sequencing (RNA-seq) studies revealed aS.

nmodulefStrataeEfficiency RNA 1) is a 115-nucleotide (nt) stress-inducible sRNA that is required for osmotic adaptation and nodule development (14) The regulatory capacity of NfeR1 relies on three identical anti-Shine-Dalgarno (aSD) motifs that redundantly contribute to translational repression

AbcR1/2 are founding members of the αr15 family and are represented in most casesRhizobacteriaceaeandBrucella familyspecies, including mammalian and plant pathogensBrucella abortusandAgrobacterium tumefaciens(23–25)

S.
MelillottiMapping analysis of AbcR1/2 sRNAs and their mRNA interactors (MeterS2onecompanypPurification of bound RNAsorder)(32,33) Our data suggest that LsrB and the alternative sigma factor RpoH1 contribute to the differential transcription of AbcR1 and AbcR2, respectively
.
In turn, these sRNAs utilize their aSD motifs to downregulate translation of large, overlapping arrays of mRNAs encoding transporters and metabolic enzymes
.
Furthermore, we found that AbcR1-mediated fine-tuning of post-transcriptional metabolism enhancesS.
MelillottiColonization of root surfaces, a symbiotic trait relevant to biotechnology
.