100 assays (manual) / 1000 assays (microplate) / 1100 assays (auto-analyser)
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|Content:||100 assays (manual) / 1000 assays (microplate) / 1100 assays (auto-analyser)|
Short term stability: 2-8oC,
Long term stability: See individual component labels
|Stability:||> 2 years under recommended storage conditions|
|Assay Format:||Spectrophotometer, Microplate, Auto-analyser|
|Linear Range:||4 to 80 µg of trehalose per assay|
|Limit of Detection:||37.5 mg/L|
|Reaction Time (min):||~ 10 min|
|Application examples:||Honey, mushrooms, bread, beer, seafood (e.g. lobster and shrimp), fruit juices, purees and fillings, nutrition bars, surimi, dehydrated fruits and vegetables, fruit products, white chocolate, sports drinks, dairy products, egg products, soups and sauces, confectionery, chewing gum, cosmetics, pharmaceuticals and other materials (e.g. biological cultures, samples, etc.).|
|Method recognition:||Novel method|
The Trehalose test kit is a simple method for the rapid and reliable measurement and analysis of trehalose in foods, beverages and other materials.
Note for Content: The number of manual tests per kit can be doubled if all volumes are halved. This can be readily accommodated using the MegaQuantTM Wave Spectrophotometer (D-MQWAVE).
Browse our full range of monosaccharide and disaccharide test kits.
- Only enzymatic kit available
- Very cost effective
- All reagents stable for > 2 years after preparation
- Very rapid reaction
- Mega-Calc™ software tool is available from our website for hassle-free raw data processing
- Standard included
- Suitable for manual, microplate and auto-analyser formats
Sulfolobus acidocaldarius uses a complex trehalose metabolism for salt stress response involving a novel TPS/TPP pathway.
Stracke, C., Meyer, B. H., Hagemann, A., Jo, E., Lee, A., Albers, S. V., Cha, J., Brasen, C. & Siebers, B. (2020). Applied and Environmental Microbiology, 86(24).
The crenarchaeon Sulfolobus acidocaldarius has been described to synthesize trehalose via the maltooligosyltrehalose synthase (TreY) and maltooligosyltrehalose trehalohydrolase (TreZ) pathway, and the trehalose glycosyltransferring synthase (TreT) pathway has been predicted. Deletion mutant analysis of strains with single and double deletions of ΔtreY and ΔtreT in S. acidocaldarius revealed that in addition to these two pathways, a third, novel trehalose biosynthesis pathway is operative in vivo: the trehalose-6-phosphate (T6P) synthase/T6P phosphatase (TPS/TPP) pathway. In contrast to known TPS proteins, which belong to the GT20 family, the S. acidocaldarius TPS belongs to the GT4 family, establishing a new function within this group of enzymes. This novel GT4-like TPS was found to be present mainly in the Sulfolobales. The ΔtreY ΔtreT Δtps triple mutant of S. acidocaldarius, which lacks the ability to synthesize trehalose, showed no altered phenotype under standard conditions or heat stress but was unable to grow under salt stress. Accordingly, in the wild-type strain, a significant increase of intracellular trehalose formation was observed under salt stress. Quantitative real-time PCR showed a salt stress-mediated induction of all three trehalose-synthesizing pathways. This demonstrates that in Archaea, trehalose plays an essential role for growth under high-salt conditions.Hide Abstract
Engineering cyanobacteria as cell factories for direct trehalose production from CO2.
Qiao, Y., Wang, W. & Lu, X. (2020). Metabolic Engineering, 62, 161-171.
Trehalose is a non-reducing disaccharide with a wide range of applications in food, cosmetic, and pharmaceutical industries. Cyanobacteria are promising cell factories to produce biochemicals by using solar energy and CO2. Trehalose is biosynthesized at low intracellular concentrations as a salt-inducible compatible solute in some cyanobacteria. In the current study, we demonstrated the efficient trehalose production without salt induction in cyanobacteria by metabolic engineering. The trehalose transporter 1 (TRET1) from an anhydrobiotic insect (Polypedilum vanderplanki) was successfully expressed in the engineered strains and the intracellular trehalose was efficiently secreted to the medium. As the results, the engineered strain co-expressing maltooligosyl trehalose synthase (MTS), maltooligosyl trehalose trehalohydrolase (MTH) and TRET1 secreted 97% of trehalose to the medium, and the titer was up to 2.7 g/L in 15 days. In addition, 5.7 g/L trehalose was produced by semi-continuous cultivation in 34 days. Taken together, this work demonstrates cyanobacteria can be applied as cell factories for direct sunlight-driven conversion of CO2 into excreted trehalose.Hide Abstract
The effect of trehalose on autophagy-related proteins and cyst growth in a hypomorphic Pkd1 mouse model of autosomal dominant polycystic kidney disease.
Atwood, D. J., Brown, C. N., Holditch, S. J., Pokhrel, D., Thorburn, A., Hopp, K. & Edelstein, C. L. (2020). Cellular Signalling, 75, 109760.
Autosomal dominant polycystic kidney disease (ADPKD) is a common inherited disorder characterized by kidney cyst growth often resulting in end-stage renal disease. There is growing attention on understanding the role of impaired autophagy in ADPKD. Trehalose (TRE) has been shown to increase both protein stability and aggregate clearance and induce autophagy in neurodegenerative diseases. TRE treatment in wild type mice compared to vehicle resulted in increased expression in the kidney of Atg12-5 complex and increased Rab9a, autophagy-related proteins that play a role in the formation of autophagosomes. Thus, the aim of the study was to determine the effect of TRE on cyst growth and autophagy-related proteins, in the hypomorphic Pkd1RC/RC mouse model of ADPKD. Pkd1RC/RC mice were treated 2% TRE in water from days 50 to 120 of age. TRE did not slow cyst growth or improve kidney function or affect proliferation and apoptosis in Pkd1RC/RC kidneys. In Pkd1RC/RC vs. wild type kidneys, expression of the Atg12-5 complex was inhibited by TRE resulting in increased free Atg12 and TRE was unable to rescue the deficiency of the Atg12-5 complex. Rab9a was decreased in Pkd1RC/RC vs. wild type kidneys and unaffected by TRE. The TRE-induced increase in p62, a marker of autophagic cargo, that was seen in normal kidneys was blocked in Pkd1RC/RC kidneys. In summary, the autophagy phenotype in Pkd1RC/RC kidneys was characterized by decreases in crucial autophagy-related proteins (Atg12-5 complex, Atg5, Atg16L1), decreased Rab9a and increased mTORC1 (pS6S240/244, pmTORS2448) proteins. TRE increased Atg12-5 complex, Rab9a and p62 in normal kidneys, but was unable to rescue the deficiency in autophagy proteins or suppress mTORC1 in Pkd1RC/RC kidneys and did not protect against cyst growth.Hide Abstract
Combination of hydrophobically modified γ-poly (glutamic acid) and trehalose achieving high cryosurvival of RBCs.
Zhang, Q., Liu, B., Chong, J., Ren, L., Zhao, Y. & Yuan, X. (2020). Science China Technological Sciences, 1-11.
Trehalose is expected to be an alternative for toxic glycerol as a biocompatible cryoprotectant of red blood cells (RBCs). In this work, γ-poly(glutamic acid) (PGA) is modified by grafting hydrophobic phenethylamine, 3,4-dimethoxyphenylethylamine and dodecylamine, respectively. The graft-modified PGA can significantly enhance cryosurvival of RBCs in combination with trehalose. Analyses of dynamic light scattering, hemolysis assay, atomic force microscope and confocal laser scanning microscope suggest that the modified PGA polymers can self-assemble into nanoparticles in phosphate buffer saline solutions at the pH range of 6.0-7.4, and exhibit membrane-disruptive activity due to hydrogen bond, conjugation and hydrophobic interactions with cell membranes. It is assumed that the modified PGA polymers can improve the cryosurvival of RBCs by promoting membrane permeability of trehalose. Among the three graft-modified polymers, phenethylamine-grafted PGA (PGA-g-PEA) can significantly increase the intracellular trehalose-loading content to 11.3±2.4 mM at pH 7.4, much higher than the value 0.17±0.66 mM when trehalose is used without any polymers. In view of the aforementioned merit, the cryosurvival rate of sheep RBCs is increased to about 90% by incubation with 1.0 mg mL-1 PGA-g-PEA and 0.36 M trehalose. In vitro cell culture of L929 fibroblasts demonstrates low cytotoxicity of PGA-g-PEA. Therefore, hydrophobic PEA-modified PGA with enhanced intracellular trehalose-loading ability can be potentially applied in glycerol-free RBC cryopreservation or other related biomacromolecule delivery systems.Hide Abstract
Sequencing and analysis of the genome of propionibacterium freudenreichii T82 strain: importance for industry.
Piwowarek, K., Lipińska, E., Hać-Szymańczuk, E., Kieliszek, M. & Kot, A. M. (2020). Biomolecules, 10(2), 348.
The genome of Propionibacterium freudenreichii ssp. Freudenreichii T82, which has a chromosome containing 2,585,340 nucleotides with 67.3% GC content (guanine-cytosine content), is described in this paper. The total number of genes is 2308, of which 2260 are protein-coding genes and 48 are RNA genes. According to the genome analysis and the obtained results, the T82 strain can produce various compounds such as propionic acid, trehalose, glycogen, and B group vitamins (e.g., B6, B9, and B12). From protein-coding sequences (CDSs), genes related to stress adaptation, biosynthesis, metabolism, transport, secretion, and defense machinery were detected. In the genome of the T82 strain, sequences corresponding to the CRISPR loci (Clustered Regularly Interspaced Short Palindromic Repeats), antibiotic resistance, and restriction–modification system were found.Hide Abstract
Unusual deprivation of compatible solutes in Acinetobacter baumannii.
Zeidler, S. & Müller, V. (2020). Environmental Microbiology, 22(4), 1370-1380.
The opportunistic human pathogen Acinetobacter baumannii is one of the leading causes of nosocomial infections. The high prevalence of multidrug‐resistant strains, a high adaptability to changing environments and an overall pronounced stress resistance contribute to persistence and spread of the bacteria in hospitals and thereby promote repeated outbreaks. Altogether, the success of A. baumannii is mainly built on adaptation and stress resistance mechanisms, rather than relying on ‘true’ virulence factors. One of the stress factors that pathogens must cope with is osmolarity, which can differ between the external environment and different body parts of the human host. A. baumannii ATCC 19606T accumulates the compatible solutes glutamate, mannitol and trehalose in response to high salinities. In this work, it was found that most of the solutes vanish immediately after reaching stationary phase, a very unusual phenomenon. While glutamate can be metabolized, mannitol produced by MtlD is excreted to the medium in high amounts. First results indicate that A. baumannii ATCC 19606T undergoes a rapid switch to a dormant state (viable but non‐culturable) after disappearance of the compatible solutes. Resuscitation from this state could easily be achieved in PBS or fresh medium.Hide Abstract
Canola cultivars affect nutrition and cold hardiness of Plutella xylostella (L.)(Lepidoptera: Plutellidae).
Nouri-Ganbalani, G., Naseri, B., Majd-Marani, S. & Borzoui, E. (2020). International Journal of Tropical Insect Science, 1-10.
The diamondback moth, Plutella xylostella (L.), has become the most destructive insect pest of Brassica crop plants, such as B. napus throughout the world including Iran. In this study, nutritional indices, digestive enzyme activity and cold hardiness of P. xylostella on seven canola cultivars including Delgan, H19, Modena, Okapi, Opera, RGS003, and SLM046 were studied under laboratory conditions (25 ± 1°C, 65 ± 5% RH, 16:8 L:D). Fourth instar larvae fed on cultivar SLM046 had the highest efficiency of conversion of ingested and digested food (4.35 ± 0.24% and 4.99 ± 0.31%, respectively). Relative consumption rate (RCR) of P. xylostella 4th instar was higher when fed on Opera cultivar (5.62 ± 0.15 mg/mg/day) while it was lower on Okapi (3.33 ± 0.15 mg/mg/day). The larvae fed on cultivars SLM046 and Okapi had the highest (0.194 ± 0.007 mg/mg/day) and the lowest (0.088 ± 0.003 mg/mg/day) relative growth rate (RGR), respectively. We found a significantly higher amylolytic and proteolytic activity in the midgut of the larvae fed cultivar SLM046. Our findings showed that the activity of enzyme inhibitors and polyphenol oxidase, as antidigestive compounds, are major reasons for the low nutritional efficiency of P. xylostella larvae on some cultivars. The results of the present study indicate that cultivar Okapi is an unsuitable host for the feeding of P. xylostella. These results develop our knowledge of the negative effects of plant defenses on P. xylostella.Hide Abstract
Partitioning sources of CO2 emission after soil wetting using high-resolution observations and minimal models.
Slessarev, E. W. & Schimel, J. P. (2020). Soil Biology and Biochemistry, 143, 107753.
complex, evolving through several stages before subsiding-possibly reflecting contributions from multiple carbon (C) sources. We hypothesized that respiration after wetting combines C from cellular sources (notably trehalose, a cellular osmo-protectant) and soluble extracellular C made available by the physical effects of wetting, with cellular sources contributing early during the pulse and extracellular C dominating later. We tested this hypothesis by making measurements of soil respiration, microbial biomass, trehalose, and water extractable organic C after wetting dry soil in the laboratory. We then devised several alternative minimal models to evaluate the potential contributions of trehalose and extracellular C to the respiration pulse. We found that the chloroform-labile fraction of the microbial biomass was comprised of 50% trehalose in dry soil. Both trehalose and water extractable organic C pools declined rapidly after wetting; trehalose disappeared within 3 h of water addition. Chloroform-labile glucose increased 3 h after water addition and then declined, suggesting rapid hydrolysis of trehalose and consumption of the resulting glucose. Respiration dynamics after wetting could be best explained by models that included two C sources, combining rapid metabolism of trehalose with slower consumption of extracellular soluble C. These results suggest that pulses of respiration after wetting reflect both osmolyte consumption within the microbial biomass and enhanced extracellular C availability; hence, models of microbial drought response must account for both processes to fully resolve soil C dynamics.Hide Abstract
Validamycin A delays development and prevents flight in Aedes aegypti (Diptera: Culicidae).
Marten, A. D., Stothard, A. I., Kalera, K., Swarts, B. M. & Conway, M. J. (2020). Journal of Medical Entomology, 57(4), 1096-1103.
Trehalose is a disaccharide that is the major sugar found in insect hemolymph fluid. Trehalose provides energy, and promotes growth, metamorphosis, stress recovery, chitin synthesis, and insect flight. The hydrolysis of trehalose is under the enzymatic control of the enzyme trehalase. Trehalase is critical to the role of trehalose in insect physiology, and is required for the regulation of metabolism and glucose generation. Trehalase inhibitors represent a novel class of insecticides that have not been fully developed. Here, we tested the ability of trehalose analogues to function as larvacides or adulticides in an important disease vector-Aedes aegypti. We show that validamycin A, but not 5-thiotrehalose, delays larval and pupal development and prevents flight of adult mosquitoes. Larval mosquitoes treated with validamycin A were hypoglycemic and pupae had increased levels of trehalose. Treatment also skewed the sex ratio toward male mosquitoes. These data reveal that validamycin A is a mosquito adulticide that can impair normal development of an important disease vector.Hide Abstract
Trehalose-Rich, Degradable Hydrogels Designed for Trehalose Release under Physiologically Relevant Conditions.
Burek, M. & Wandzik, I. (2019). Polymers, 11(12), 2027.
Trehalose, a natural disaccharide, is primarily known for its ability to protect proteins from inactivation and denaturation caused by a variety of stress conditions. Furthermore, over the past few years, it has emerged as a promising therapeutic candidate for treatment of neurodegenerative diseases. Herein, we examine the attachment of trehalose to polymers for release under selected physiologically relevant conditions. The proposed strategies are evaluated specifically using hydrogels undergoing simultaneous degradation during trehalose release. These materials are fabricated via copolymerization of the appropriate acrylamide-type monomers with polymerizable trehalose esters or benzylidene acetals. This provides trehalose release in a slightly alkaline (i.e., pH 7.4) or mildly acidic (i.e., pH 5.0) environment, respectively. Using this method materials containing up to 51.7 wt% of trehalose are obtained. The presented results provide a solid basis for future studies on polymeric materials intended for trehalose release in biological systems.Hide Abstract
Redox control of yeast Sir2 activity is involved in acetic acid resistance and longevity.
Espinosa, V. L., Mir, N., Garrido, L., Vived Maza, C. & Cabiscol Català, E. (2019). Redox Biology, 24, 101129.
Yeast Sir2 is an NAD-dependent histone deacetylase related to oxidative stress and aging. In a previous study, we showed that Sir2 is regulated by S-glutathionylation of key cysteine residues located at the catalytic domain. Mutation of these residues results in strains with increased resistance to disulfide stress. In the present study, these mutant cells were highly resistant to acetic acid and had an increased chronological life span. Mutant cells had increased acetyl-CoA synthetase activity, which converts acetic acid generated by yeast metabolism to acetyl.CoA. This could explain the acetic acid resistance and lower levels of this toxic acid in the extracellular media during aging. Increased acetyl-CoA levels would raise lipid droplets, a source of energy during aging, and fuel glyoxylate-dependent gluconeogenesis. The key enzyme of this pathway, phosphoenolpyruvate carboxykinase (Pck1), showed increased activity in these Sir2 mutant cells during aging. Sir2 activity decreased when cells shifted to the diauxic phase in the mutant strains, compared to the WT strain. Since Pck1 is inactivated through Sir2-dependent deacetylation, the decline in Sir2 activity explained the rise in Pck1 activity. As a consequence, storage of sugars such as trehalose would increase. We conclude that extended longevity observed in the mutants was a combination of increased lipid droplets and trehalose, and decreased acetic acid in the extracellular media. These results offer a deeper understanding of the redox regulation of Sir2 in acetic acid resistance, which is relevant in some food and industrial biotechnology and also in the metabolism associated to calorie restriction, aging and pathologies such as diabetes.Hide Abstract
Inertial cavitation of lyophilized and rehydrated nanoparticles of poly (L-lactic acid) at 835 kHz and 1.8 MPa ultrasound.
Hiltl, P., Grebner, A., Fink, M., Rupitsch, S., Ermert, H. & Lee, G. (2019). Scientific Reports, 9(1), 1-10.
Nanoparticles of poly-L-lactic acid dispersed in water and of approximately 120 nm diameter were prepared by a nanoprecipitation method followed by lyophilization together with trehalose. After rehydration, the nanodispersion was exposed to ultrasound at 835 kHz frequency and 1.8 MPa peak negative sound pressure. Substantial levels of broadband noise were surprisingly detected which are attributed to the occurance of inertial cavitation of bubbles present in the dispersion. Inertial cavitation encompasses the formation and growth of gas cavities in the rarefaction pressure cycle which collapse in the compression cycle because of the inwardly-acting inertia of the contracting gas-liquid interface. The intensity of this inertial cavitation over 600 s was similar to that produced by Optison microbubbles used as contrast agents for diagnostic ultrasound. Non-lyophilized nanodispersions produced negligible broadband noise showing that lyophilization and rehydration are requirements for broadband activity of the nanoparticles. Photon correlation spectroscopy indicates that the nanoparticles are not highly aggregated in the nanodispersion and this is supported by scanning (SEM) and transmission (TEM) electron micrographs. TEM visualized non-spherical nanoparticles with a degree of irregular, non-smooth surfaces. Although the presence of small aggregates with inter-particulate gas pockets cannot be ruled out, the inertial cavitation activity can be explained by incomplete wetting of the nanoparticle surface during rehydration of the lyophilizate. Nano-scale gas pockets may be trapped in the surface roughness of the nanoparticles and may be released and coalesce to the size required to nucleate inertial cavitation on insonation at 835 kHz/1.8 MPa.Hide Abstract
Strain-dependent variance in short-term adaptation effects of two xylose-fermenting strains of Saccharomyces cerevisiae.
Van Dijk, M., Erdei, B., Galbe, M., Nygård, Y. & Olsson, L. (2019). Bioresource Technology, 292, 121922.
The limited tolerance of Saccharomyces cerevisiae to the inhibitors present in lignocellulosic hydrolysates is a major challenge in second-generation bioethanol production. Short-term adaptation of the yeast to lignocellulosic hydrolysates during cell propagation has been shown to improve its tolerance, and thus its performance in lignocellulose fermentation. The aim of this study was to investigate the short-term adaptation effects in yeast strains with different genetic backgrounds. Fed-batch propagation cultures were supplemented with 40% wheat straw hydrolysate during the feed phase to adapt two different pentose-fermenting strains, CR01 and KE6-12. The harvested cells were used to inoculate fermentation media containing 80% or 90% wheat straw hydrolysate. The specific ethanol productivity during fermentation was up to 3.6 times higher for CR01 and 1.6 times higher for KE6-12 following adaptation. The influence of physiological parameters such as viability, storage carbohydrate content, and metabolite yields following short-term adaptation demonstrated that short-term adaptation was strain dependent.Hide Abstract
Tumor-derived ligands trigger tumor growth and host wasting via differential MEK activation.
Song, W., Kir, S., Hong, S., Hu, Y., Wang, X., Binari, R., Tang, H. W., Chung, V., Banks, A. S., Spiegelman, B. & Perrimon, N. (2019). Developmental Cell, 48(2), 277-286.
Interactions between tumors and host tissues play essential roles in tumor-induced systemic wasting and cancer cachexia, including muscle wasting and lipid loss. However, the pathogenic molecular mechanisms of wasting are still poorly understood. Using a fly model of tumor-induced organ wasting, we observed aberrant MEK activation in both tumors and host tissues of flies bearing gut-yki3SA tumors. We found that host MEK activation results in muscle wasting and lipid loss, while tumor MEK activation is required for tumor growth. Strikingly, host MEK suppression alone is sufficient to abolish the wasting phenotypes without affecting tumor growth. We further uncovered that yki3SA tumors produce the vein (vn) ligand to trigger autonomous Egfr/MEK-induced tumor growth and produce the PDGF- and VEGF-related factor 1 (Pvf1) ligand to non-autonomously activate host Pvr/MEK signaling and wasting. Altogether, our results demonstrate the essential roles and molecular mechanisms of differential MEK activation in tumor-induced host wasting.Hide Abstract
Rapid and continuous on-chip loading of trehalose into erythrocytes.
Shen, Y., Du, K., Zou, L., Zhou, X., Lv, R., Gao, D., Qiu, B. & Ding, W. (2019). Biomedical Microdevices, 21(1), 5.
Freeze-drying is a promising approach for the long-term storage of erythrocytes at room temperature. Studies have shown that trehalose loaded into erythrocytes plays an important role in protecting erythrocytes against freeze-drying damage. Due to the impermeability of the erythrocyte membrane to trehalose, many methods have been developed to load trehalose into erythrocytes. However, these methods usually require multistep manual manipulation and long processing time; the adopted protocols are also diverse and not standardized. Thus, we develop an osmotically-based trehalose-loading microdevice (TLM) to rapidly, continuously, and automatically produce erythrocytes with loaded trehalose. In the TLM, trehalose is loaded through the erythrocyte membrane pores induced by hypotonic shock; then, the trehalose-loaded erythrocytes are rinsed to remove hemoglobin molecules and cell fragments, and the extracellular solution is restored to the isotonic state by integrating a rinsing-recovering design. First, the mixing function and the rinsing-recovering function were confirmed using a fluorescent solution. Then, the performance of the TLM was evaluated under various operating conditions with respect to the loading efficiency of trehalose, the hemolysis rate of erythrocytes (ϕ), the recovery rate of hemoglobin in erythrocytes (φ), and the separation efficiency of the TLM. Finally, the preliminary study of the freeze-drying of erythrocytes with loaded trehalose was accomplished using the TLM. The results showed that under the designated operating conditions, the loading efficiency for human erythrocytes reached ~21 mM in ~2 min with a ϕ value of ~17% and a φ value of ~74%. This study provides insights into the design of the on-chip loading of trehalose into erythrocytes and promotes the automation of life science studies on biochips.Hide Abstract
Cold stress induces biochemical changes, fatty acid profile, antioxidant system and gene expression in Capsella bursa pastoris L.
Wani, M. A., Jan, N., Qazi, H. A., Andrabi, K. I. & John, R. (2018). Acta Physiologiae Plantarum, 40(9), 1-14.
In the present study, we analysed the response of 30 day old seedlings of Capsella bursa-pastoris to cold stress (CS). Seeds of C. bursa-pastoris were grown at 25°C for 1 month and then exposed to low temperature of 10°C. Plant tissues were collected at different time points (24, 48, 72, 96 and 120 h) and assayed for change in osmoprotectants, fatty acid composition of membrane system and antioxidant enzymes. We also analysed the gene expression of important stress related transcription factors (TF) such as, LEA (Late embryogenesis abundant) and DREB (Dehydration responsive element binding). A significant increase in the levels of several osmoprotectants such as proline (Pro), glycine betaine (GB), free amino acids, total proteins, total soluble sugars and trehalose was observed. CS increased membrane fluidity by changing the ratio of saturated and unsaturated fatty acids in membranes which in turn resulted in significant ion leakage. CS in C. bursa-pastoris led to a significant decrease in photosynthetic pigments and ultimately altered the overall growth and biomass. Similarly, significant changes in antioxidant enzymes were observed, POD (peroxidase), CAT (cataalase), SOD (superoxide dismutase) and GR (glutathione reductase) increased significantly while as APX (ascorbate peroxidase) declined in response to CS. We assessed the transcriptional expression using qRT-PCR of these antioxidant genes coordinated with their enzyme activities. Additionally, in C. bursa-pastoris cold inducible genes encoding DREB and LEA (protein also got upregulated under CS). The present study suggests that C. bursa-pastoris responded to CS efficiently by changing its different metabolic pathways, antioxidant system, fatty acid composition and gene expression.Hide Abstract
Cold acclimation conditions constrain plastic responses for resistance to cold and starvation in Drosophila immigrans.
Pathak, A., Munjal, A. & Parkash, R. (2018). Biology Open, 7(6).
In montane Drosophila species, cold-induced plastic changes in energy metabolites are likely developed to cope with cold and starvation stress. Adult Drosophila immigrans reared at 15°C were acclimated at 0°C or 7°C for durations of up to 6 days (fed or unfed conditions). Such flies were tested for plastic changes in resistance to cold or starvation stress as well as for possible accumulation and utilization of four energy metabolites (body lipids, proline, trehalose and glycogen). Adults acclimated at 7°C revealed a greater increase in cold tolerance than flies acclimated at 0°C. Different durations of cold acclimation at 7°C led to increased level of body lipids only in fed flies which were utilized under starvation stress. However, such plastic responses were not observed in the flies acclimated at 0°C, which remained unfed due to chill-coma. These observations suggest a possible role of feeding to improve starvation resistance only in the flies acclimated at 7°C with food. Cold acclimated D. immigrans flies revealed improved cold resistance through a possible reshuffling of trehalose and glycogen; and starvation-induced proline which was utilized under cold stress durations. Finally, greater reduction in mean daily fecundity due to cold or starvation was observed in 0°C acclimated flies as compared to 7°C acclimated flies. Thus, cold acclimation conditions (0°C or 7°C) greatly impact resistance to cold and starvation in D. immigrans.Hide Abstract
Cold stress modulates osmolytes and antioxidant system in Calendula officinalis.
Jan, N., Majeed, U., Andrabi, K. I. & John, R. (2018). Acta Physiologiae Plantarum, 40(4), 1-16.
Understanding the mechanism of adaptation to low-temperature stress is very crucial for developing cold-tolerant crop plants. The present study was used to investigate the response of Calendula officinalis (C. officinalis) to cold stress (CS). Seeds of C. officinalis were grown at normal temperature of 25°C for 14 days and then shifted to a growth chamber set at 4°C. The response of C. officinalis seedlings to cold stress was evaluated by estimating the relative growth changes, chlorophyll, electrolyte leakage (EL) and the content of malondialdehyde (MDA), proline, glycine betaine (GB), total soluble sugars, trehalose, total protein content and fatty acid profile. Enzymatic activity of antioxidants such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) was also assessed. Moreover, transcript expression of cold-responsive genes [APX, CAT, dehydration-responsive element-binding protein (DREB1), GR and SOD] was also evaluated on homology basis. We measured and compared these indices of seedlings leaves under low temperature (4°C) and normal temperature (25°C) and observed that on exposure to CS, C. officinalis shows higher accumulation of osmoprotectants (proline, soluble sugars, glycine betaine and trehalose), phenolics and proteins, and increased antioxidant enzyme activity (APX, GR and SOD) except CAT activity, which declined in cold-stressed plants. Transcript expression of cold-responsive genes (SOD, CAT, APX, GR and DREB1) was found to be upregulated under cold stress. Overall, our study suggests that cold exposure/CS, besides eliciting various biochemical/physiological responses, triggers various pathways causing differential gene expression, consequently leading to differential protein expression. Further, this is the first report of C. officinalis under cold stress that may help us in exploring the mechanism of cold tolerance in future.Hide Abstract
Gene expression profiles of Candida glycerinogenes under combined heat and high-glucose stresses.
Yang, F., Lu, X., Zong, H., Ji, H. & Zhuge, B. (2018). Journal of Bioscience and Bioengineering, 126(4), 464-469.
Low cell tolerance is a basic issue in high-glucose fermentation under high temperature to economically obtain high product titer. Candida glycerinogenes, an industrial yeast, has excellent tolerance to the combined heat and high-glucose stress than Saccharomyces cerevisiae. The potential mechanism responsible for the high tolerance was illustrated here. The transcription of the potential stress-responsive genes in two strains were varied under single stress (heat or high-glucose), especially the ribosome-related genes. Unlike S. cerevisiae, C. glycerinogenes up-regulated 17 genes, including most of the single stress responsive genes, and genes Avt1 and Pfk1 under the combined stress, indicating a more systematic stress-responsive system in C. glycerinogenes. Further down-regulating the 17 potential key responsive genes indicated that genes Dip5, Gpd1, Pfk1, Hxt4, Hxt6, and Ino4 are important for cell tolerance to the combined stress. Furthermore, most of the ribosomal function related genes, such as Mrt4, Nug1, Nop53, Rpa190, Rex4, and Nsr1, play important role in cell tolerance. Therefore, the wider responsive gene spectrum and the activated expression of ribosomal function related genes might be key and prerequisite factors for the excellent tolerance to the combined stress of C. glycerinogenes.Hide Abstract