Arginine as an environmental and metabolic cue for cyclic diguanylate signalling and biofilm formation in Pseudomonas putida

Abstract

Cyclic diguanylate (c-di-GMP) is a broadly conserved intracellular second messenger that influences different bacterial processes, including virulence, stress tolerance or social behaviours and biofilm development. Although in most cases the environmental cue that initiates the signal transduction cascade leading to changes in cellular c-di-GMP levels remains unknown, certain l - and d -amino acids have been described to modulate c-di-GMP turnover in some bacteria. In this work, we have analysed the influence of l -amino acids on c-di-GMP levels in the plant-beneficial bacterium Pseudomonas putida KT2440, identifying l -arginine as the main one causing a significant increase in c-di-GMP. Both exogenous (environmental) and endogenous (biosynthetic) l -arginine influence biofilm formation by P. putida through changes in c-di-GMP content and altered expression of structural elements of the biofilm extracellular matrix. The contribution of periplasmic binding proteins forming part of amino acid transport systems to the response to environmental l -arginine was also studied. Contrary to what has been described in other bacteria, in P. putida these proteins seem not to be directly responsible for signal transduction. Rather, their contribution to global l -arginine pools appears to determine changes in c-di-GMP turnover. We propose that arginine plays a connecting role between cellular metabolism and c-di-GMP signalling in P. putida .

Genetic factors involved in rhizosphere colonization by phytobeneficial Pseudomonas spp.

“…The authors posited that the loss of SpuC caused physiological changes in the bacteria responsible for plant recognition, and that putrescine or its precursor, arginine, might be signalling molecules in the rhizosphere used by the bacteria to evade the plant immune response. This is consistent with recent results obtained by Barrientos‑Moreno et al indicating that arginine promotes biofilm formation through an increase in cyclic-di-GMP concentration [180] . Phase variation may also be used by rhizosphere Pseudomonas spp.…”

Genome-Wide Analysis of Targets for Post-Transcriptional Regulation by Rsm Proteins in Pseudomonas putida

“…Previous reports have established that hisP and genes involved in lysine catabolism are preferentially expressed in KT2440 in the rhizosphere of corn plants ( Espinosa-Urgel and Ramos, 2001 ; Matilla et al, 2007 ). In addition, a connection beween arginine transport and c-di-GMP signaling in this strain has been recently reported ( Barrientos-Moreno et al, 2020 ). These facts, and the influence of Rsm proteins on biofilm formation and surface motility, along with the identification of c-di-GMP turnover elements and other biofilm-related genes as targets of these proteins, made us analyze if mutants in rsm genes showed altered fitness in the rhizosphere.…”

“…In most cases, expression was enhanced in the mutant, indicating that the observed binding to their RNA targets leads to translation repression by these proteins; these results are consistent with previous observations on their influence upon biofilm-related elements (see below). However, the inverse was true for two of the tested fusions, those corresponding to PP_1088 ( argG , involved in arginine synthesis; Ramos-González et al, 2016 ) and PP_4482 (part of the gene cluster encoding the main arginine transporter and its regulator; Barrientos-Moreno et al, 2020 ). In these cases, expression was approximately halved in the mutant with respect to the wild type.…”

Understanding the Interactions between Staphylococcus aureus and the Raw-Meat-Processing Environment Isolate Klebsiella oxytoca in Dual-Species Biofilms via Discovering an Altered Metabolic Profile

“…L-AAs are the dominant substrates for ribosome-based protein synthesis [ 25 ]. Barrientos-Moreno, Molina-Henares, Ramos-Gonzalez, and Espinosa-Urgel found that both exogenous and endogenous L-arginine affect biofilm formation of Pseudomonas putida through changes in cyclic diguanylate content, and altered expression of structural elements of the biofilm extracellular matrix [ 26 ]. Velmourougane and Prasanna revealed that since L-AAs (mainly L-Glu, L-Gln, L-His, L-Ser, L-Thr and L-Trp) affect the growth, aggregation, and carbohydrate synthesis of microorganisms, they are essential for the formation of biofilms [ 23 ].…”