Integrative analysis of the salt stress response in cyanobacteria

Abstract

Microorganisms evolved specific acclimation strategies to thrive in environments of high or fluctuating salinities. Here, salt acclimation in the model cyanobacterium Synechocystis sp. PCC 6803 was analyzed by integrating transcriptomic, proteomic and metabolomic data. A dynamic reorganization of the transcriptome occurred during the first hours after salt shock, e.g. involving the upregulation of genes to activate compatible solute biochemistry balancing osmotic pressure. The massive accumulation of glucosylglycerol then had a measurable impact on the overall carbon and nitrogen metabolism. In addition, we observed the coordinated induction of putative regulatory RNAs and of several proteins known for their involvement in other stress responses. Overall, salt-induced changes in the proteome and transcriptome showed good correlations, especially among the stably up-regulated proteins and their transcripts. We define an extended salt stimulon comprising proteins directly or indirectly related to compatible solute metabolism, ion and water movements, and a distinct set of regulatory RNAs involved in post-transcriptional regulation. Our comprehensive data set provides the basis for engineering cyanobacterial salt tolerance and to further understand its regulation.

The impact of the cyanobacterial carbon‐regulator protein SbtB and of the second messengers cAMP and c‐di‐AMP on CO2‐dependent gene expression

“…It should be noted that none of the genes encoding proteins involved in compatible solute biosynthesis or transport, or potassium homeostasis, which are thought to be associated with c‐di‐AMP in bacteria (Nelson et al ., 2013; Agostoni et al ., 2018; Selim et al ., 2021), showed significant alterations in expression in Δ dacA compared to WT. However, the expression of other genes such as nhaS6 , hliA , hliB , or sll1483 , which had been previously shown to be transcriptionally regulated following salt stress in Synechocystis (Kanesaki et al ., 2002; Klähn et al ., 2021), was different in Δ dacA compared to WT in the present study. Furthermore, the gene slr0753 , which was shown to be regulated by the c‐di‐AMP‐dependent riboswitch in the present study (Fig.…”

Multi-Omics Approach Reveals Dysregulation of Protein Phosphorylation Correlated with Lipid Metabolism in Mouse Non-Alcoholic Fatty Liver

“…We then performed a Student’s t -test to unveil proteins that were significantly regulated after DIO. A volcano plot representation of our filtered data shows that the distribution of upregulated and downregulated proteins was remarkably symmetrical, with 312 proteins above the q < 0.05 and 0.38 |log 2 (fold-change)| cutoffs [ 21 , 22 , 23 , 24 , 25 ], set as the minimum to consider proteins as “significantly regulated” ( Figure 3 B). Specifically, 141 proteins were downregulated and 171 were upregulated.…”

The survivor strain: isolation and characterization of Phormidium yuhuli AB48, a filamentous phototactic cyanobacterium with biotechnological potential

“…In response to a high salinity environment, an increase in the expression of the Na + /H + antiporter KefB (1.4-fold) was observed with a concomitant decrease in the expression of BicA, CmpC, and CmpB (1.6-fold–1.8-fold), involved in the bicarbonate transport ( Supplementary Figure S6 ). In addition to genes related to inorganic ion transportation, variation in the expression of several genes related to metabolism and transport of compatible solutes was observed, as well as the accumulation of compatible solutes in P. yuhuli AB48 biomass ( Hagemann, 2011 ; Pade and Hagemann, 2014 ; Kirsch et al, 2019 ; Klähn et al, 2021 ). These included a 3.4-fold increase in glycerol-3-phophate dehydrogenase, GlpA, expression and a 3.9-fold and 2.9-fold decrease in PulA and AmyA expression, which are involved in polysaccharide biosynthesis and degradation, respectively.…”