Project description:In order to reveal so far unknown facets of the adaptation of B. subtilis to growth under high-salinity conditions, a whole-transcriptome analysis of B. subtilis BSB (168 Trp+) was performed using strand-specific tiling arrays (tiling step of 22 nucleotides). In addition, the effects of glycine betaine (GB) were analyzed under high salinity and standard growth conditions in a chemically defined medium. Important novel findings were a sustained low-level induction of the SigB-dependent general stress response and strong repression of biofilm matrix genes under high-salinity conditions. GB influences gene expression not only under high-salinity, but also under standard growth conditions without additional salt.
Project description:Melatonin plays a potential role in multiple plant developmental processes and stress response. However, there are no reports regarding exogenous melatonin promoting rice seed germination under salinity and nor about the underlying molecular mechanisms at genome-wide. Here, we revealed that exogenous application of melatonin conferred roles in promoting rice seed germination under salinity. The putative molecular mechanisms of exogenous melatonin in promoting rice seed germination under high salinity were further investigated through metabolomic and transcriptomic analyses. The results state clearly that the phytohormone contents were reprogrammed, the activities of SOD, CAT, POD were enhanced, and the total antioxidant capacity was activated under salinity by exogenous melatonin. Additionally, melatonin-pre-treated seeds exhibited higher concentrations of glycosides than non-treated seeds under salinity. Furthermore, exogenous melatonin alleviated the accumulation of fatty acids induced by salinity. Genome-wide transcriptomic profiling identified 7160 transcripts that were differentially expressed in NaCl, MT100 and control. Pathway and GO term enrichment analysis revealed that genes involved in the response to oxidative stress, hormone metabolism, heme building, mitochondrion, tricarboxylic acid transformation were altered after melatonin pre-treatment under salinity. This study provides the first evidence of the protective roles of exogenous melatonin in increasing rice seed germination under salt stress, mainly via activation of antioxidants and modulation of metabolic homeostasis.
Project description:The mechanisms of cellular and molecular adaptation of fungi to salinity have been commonly drawn from halotolerant strains, although some exceptions in basidiomycete fungi can be found. These studies have been conducted in settings where cells are subjected to stress, either hypo or hyperosmotic, which can be a confounding factor in describing physiological mechanisms related to salinity. Here, we have studied transcriptomic changes in Aspergillus sydowii, a halophilic species, when growing in three different salinity conditions (No salt, 0.5M and 2.0M NaCl). In this fungus salinity related responses occur under high salinity (2.0M NaCl) and not when cultured under optimal conditions (0.5M NaCl), suggesting that in this species, most of the mechanisms described for halophilic growth are a consequence of saline stress response and not an adaptation to saline conditions.
2019-12-31 | GSE139804 | GEO
Project description:Transcriptional differences of functional genes of aerobic microorganisms under different salinity
Project description:LCMS of mangrove propagule extracts incubated under different conditions (high vs low salinity, antibiotic vs antibiotic+antifungal vs control).
Project description:Salinity is one of the significant factors that affect growth and cellular metabolism, including photosynthesis and lipid accumulation, in microalgae and higher plants. Microchloropsis gaditana CCMP526 can acclimatize to different salinity levels by accumulating compatible solutes, carbohydrates, and lipid as an energy storage molecule. We used proteomics to understand the molecular basis for acclimation of M. gaditana to increased salinity levels (55 and 100 PSU). Correspondence analysis (CA) was used for identification of salinity-responsive proteins (SRPs). The highest number of altered proteins was observed in 100 PSU. Gene Ontology (GO) enrichment analysis revealed a separate path of acclimation for cells exposed to 55 and 100 PSU. Osmolyte and lipid biosynthesis was up-regulated in high saline conditions. However, concomitantly lipid oxidation pathways were also up-regulated at high saline conditions, providing acetyl-CoA for energy metabolism through the TCA cycle. Carbon fixation and photosynthesis were tightly regulated, while chlorophyll biosynthesis was affected under high salinity conditions. Importantly, temporal proteome analysis of salinity-challenged M. gaditana revealed vital salinity-responsive proteins which could be used for strain engineering for improved salinity resistance.
Project description:Salinity is one of the significant factors that affect growth and cellular metabolism, including photosynthesis and lipid accumulation, in microalgae and higher plants. Microchloropsis gaditana CCMP526 can acclimatize to different salinity levels by accumulating compatible solutes, carbohydrates, and lipid as an energy storage molecule. We used proteomics to understand the molecular basis for acclimation of M. gaditana to increased salinity levels (55 and 100 PSU). Correspondence analysis (CA) was used for identification of salinity-responsive proteins (SRPs). The highest number of altered proteins was observed in 100 PSU. Gene Ontology (GO) enrichment analysis revealed a separate path of acclimation for cells exposed to 55 and 100 PSU. Osmolyte and lipid biosynthesis was up-regulated in high saline conditions. However, concomitantly lipid oxidation pathways were also up-regulated at high saline conditions, providing acetyl-CoA for energy metabolism through the TCA cycle. Carbon fixation and photosynthesis were tightly regulated, while chlorophyll biosynthesis was affected under high salinity conditions. Importantly, temporal proteome analysis of salinity-challenged M. gaditana revealed vital salinity-responsive proteins which could be used for strain engineering for improved salinity resistance.