Trehalose Content Research Articles

Supplemental Sugar Is Required for Sex Pheromone Biosynthesis in Mythimna separata.

Supplemental nutrients of adult moths maximize moth fitness and contribute to the pollination of many plants. Previous reports have revealed that sugar feeding promotes to sex pheromone biosynthesis by increasing the haemolymph trehalose concentration in mating moths. Here, Mythimna separata adults were employed as a model to investigate the effect of sugar feeding on sex pheromone biosynthesis. Results showed that in virgin females, sugar feeding markedly increased the concentrations of trehalose, pyruvic acid, and acyl-CoA in pheromone glands (PGs), which in turn led to an increase in sex pheromone titer, female ability to attract males and successfully mating frequency in sugar-fed females. Consistently, sugar-fed females laid more eggs than water-fed females. Furthermore, the refeeding of starved females also caused significantly increase in the concentrations of trehalose, pyruvic acid, and acyl-CoA in PGs, thus facilitating a significant increase in sex pheromone production. Most importantly, RNAi-mediated knockdown of trehalase (leading to PG starvation) resulted in an increase in trehalose content, and decrease in the concentrations of pyruvic acid, and acyl-CoA in PGs, which in turn led to a decrease of sex pheromone titer, female ability to attract males and successful mating efficacy. Altogether, results revealed a mechanism by which sugar feeding contributed to trehalose utilization in PGs, promoted to significantly increased sex pheromone precursor by increasing the concentrations of pyruvic acid and acyl-CoA, and facilitated to sex pheromone biosynthesis and successful mating.

Inorganic Phosphate Solubilization by Rhizosphere Bacterium Paenibacillus sonchi: Gene Expression and Physiological Functions.

Due to the importance of phosphorus (P) in agriculture, crop inoculation with phosphate-solubilizing bacteria is a relevant subject of study. Paenibacillus sonchi genomovar Riograndensis SBR5 is a promising candidate for crop inoculation, as it can fix nitrogen and excrete ammonium at a remarkably high rate. However, its trait of phosphate solubilization (PS) has not yet been studied in detail. Here, differential gene expression and functional analyses were performed to characterize PS in this bacterium. SBR5 was cultivated with two distinct P sources: NaH2PO4 as soluble phosphate source (SPi) and hydroxyapatite as insoluble phosphate source (IPi). Total RNA of SBR5 cultivated in those two conditions was isolated and sequenced, and bacterial growth and product formation were monitored. In the IPi medium, the expression of 68 genes was upregulated, whereas 100 genes were downregulated. Among those, genes involved in carbon metabolism, including those coding for subunits of 2-oxoglutarate dehydrogenase, were identified. Quantitation of organic acids showed that the production of tricarboxylic acid cycle-derived organic acids was reduced in IPi condition, whereas acetate and gluconate were overproduced. Increased concentrations of proline, trehalose, and glycine betaine revealed active osmoprotection during growth in IPi. The cultivation with hydroxyapatite also caused the reduction in the motility of SBR5 cells as a response to Pi depletion at the beginning of its growth. SBR5 was able to solubilize hydroxyapatite, which suggests that this organism is a promising phosphate-solubilizing bacterium. Our findings are the initial step in the elucidation of the PS process in P. sonchi SBR5 and will be a valuable groundwork for further studies of this organism as a plant growth-promoting rhizobacterium.

Evaluation of ethanol tolerance in relation to intracellular storage compounds of Saccharomyces cerevisiae using FT-IR spectroscopy

During ethanol fermentation, ethanol accumulates in the medium and becomes a significant stress factor for yeast. Trehalose and glycogen are major carbohydrate storages and presumably protect cells from such stress conditions. In this study, batch cultivations of wild and adapted Saccharomyces cerevisiae were performed to evaluate the fermentation kinetics and carbohydrate storages, interrelatedly. Trehalose and glycogen were determined by both High Performance Liquid Chromatography (HPLC) and Fourier Transform-Infrared (FT-IR) spectroscopy for comparison. The obtained maximum trehalose and glycogen (7.5 and 10.5 %) contents of the adapted strain was remarkably higher compared to the wild strain (5 and 6.5 %). The adapted S. cerevisiae displayed an enhanced fermentation stresses coping ability resulting in a higher ethanol productivity (2.03 vs 1.65 g ethanol/h) as well as higher ethanol titer (7.7 vs 6.4 %). This study contributes to the understanding of the cellular response of S. cerevisiae cells to fermentation stresses in relation to culture history together with the evaluation of fermentation performance, as well as the process kinetics. This study also confirms that FT-IR spectroscopy of whole S. cerevisiae cells for determination of storage compounds without pretreatment has valuable advantages compared to HPLC with intensive sample handling.

Regulatory Functions of Nilaparvata lugens GSK-3 in Energy and Chitin Metabolism.

Glucose metabolism is a biologically important metabolic process. Glycogen synthase kinase (GSK-3) is a key enzyme located in the middle of the sugar metabolism pathway that can regulate the energy metabolism process in the body through insulin signaling. This paper mainly explores the regulatory effect of glycogen synthase kinase on the metabolism of glycogen and trehalose in the brown planthopper (Nilaparvata lugens) by RNA interference. In this paper, microinjection of the target double-stranded GSK-3 (dsGSK-3) effectively inhibited the expression of target genes in N. lugens. GSK-3 gene silencing can effectively inhibit the expression of target genes (glycogen phosphorylase gene, glycogen synthase gene, trehalose-6-phosphate synthase 1 gene, and trehalose-6-phosphate synthase 2 gene) in N. lugens and trehalase activity, thereby reducing glycogen and glucose content, increasing trehalose content, and regulating insect trehalose balance. GSK-3 can regulate the genes chitin synthase gene and glucose-6-phosphate isomerase gene involved in the chitin biosynthetic pathway of N. lugens. GSK-3 gene silencing can inhibit the synthesis of chitin N. lugens, resulting in abnormal phenotypes and increased mortality. These results indicated that a low expression of GSK-3 in N. lugens can regulate the metabolism of glycogen and trehalose through the insulin signal pathway and energy metabolism pathway, and can regulate the biosynthesis of chitin, which affects molting and wing formation. The relevant research results will help us to more comprehensively explore the molecular mechanism of the regulation of energy and chitin metabolism of insect glycogen synthase kinases in species such as N. lugens.

PEGylated polymeric nanocapsules for oral delivery of trypsin targeted to the small intestines

The lack of trypsin in the intestines may end up with malnutrition; thus, trypsin replacement therapy is required in such cases. The main objective of this study is to formulate and evaluate polymeric nanocapsule (PNC) systems able to deliver trypsin to the small intestines with the minimal release in the stomach with the maximum biological activity. Four nanocapsule formulations were prepared by double emulsion/evaporation method as w/o/w and s/o/w. Particle size, encapsulation efficiencies, drug release in simulated gastric fluids (SGF) and simulated intestinal fluids (SIF), morphology, the biological activity of encapsulated trypsin and shelf-life stability were investigated for all formulations. All formulations had a spherical shape with submicron size, and encapsulation efficiency more than 80%. The biological activity of encapsulated trypsin was significantly affected by the amount of trehalose and whether the formulations were prepared as s/o/w or w/o/w (P < 0.05). Most of the encapsulated protein was released sustainedly at the target site (SIF) over 24 h with minimum amount release in the gastric fluids. Also, more than 90% of physical integrity trypsin encapsulated in all formulations was retained after storage under chilled conditions for six months. However, the enzymatic assay results show that with low trehalose content, the biological activity was low, while increasing the trehalose amount increased the shelf stability to reach around 100% after six months of the study. The results obtained in this research work clearly indicated a promising potential of controlled release polymeric nanocapsules containing trypsin to target the small intestine and protect trypsin from the harsh condition facing the proteins during the process of preparation or the period of storage.

Social Chemical Communication Determines Recovery From L1 Arrest via DAF-16 Activation.

In a population, chemical communication determines the response of animals to changing environmental conditions, what leads to an enhanced resistance against stressors. In response to starvation, the nematode Caenorhabditis elegans arrest post-embryonic development at the first larval stage (L1) right after hatching. As arrested L1 larvae, C. elegans become more resistant to diverse stresses, allowing them to survive for several weeks expecting to encounter more favorable conditions. L1 arrested at high densities display an enhanced resistance to starvation, dependent on soluble compounds released beyond hatching and the first day of arrest. Here, we show that this chemical communication also influences recovery after prolonged periods in L1 arrest. Animals at high density recovered faster than animals at low density. We found that the density effect on survival depends on the final effector of the insulin signaling pathway, the transcription factor DAF-16. Moreover, DAF-16 activation was higher at high density, consistent with a lower expression of the insulin-like peptide DAF-28 in the neurons. The improved recovery of animals after arrest at high density depended on soluble compounds present in the media of arrested L1s. In an effort to find the nature of these compounds, we investigated the disaccharide trehalose as putative signaling molecule, since its production is enhanced during L1 arrest and it is able to activate DAF-16. We detected the presence of trehalose in the medium of arrested L1 larvae at a low concentration. The addition of this concentration of trehalose to animals arrested at low density was enough to rescue DAF-28 production and DAF-16 activation to the levels of animals arrested at high density. However, despite activating DAF-16, trehalose was not capable of reversing survival and recovery phenotypes, suggesting the participation of additional signaling molecules. With all, here we describe a molecular mechanism underlying social communication that allows C. elegans to maintain arrested L1 larvae ready to quickly recover as soon as they encounter nutrient sources.

Trehalose as quantitative biomarker for in vivo diagnosis and treatment follow-up in cryptococcomas

Brain lesions caused by Cryptococcus neoformans or C. gattii (cryptococcomas) are typically difficult to diagnose correctly and treat effectively, but rapid differential diagnosis and treatment initiation are crucial for good outcomes. In previous studies, cultured cryptococcal isolates and ex vivo lesion material contained high concentrations of the virulence factor and fungal metabolite trehalose. Here, we studied the in vivo metabolic profile of cryptococcomas in the brain using magnetic resonance spectroscopy (MRS) and assessed the relationship between trehalose concentration, fungal burden, and treatment response in order to validate its suitability as marker for early and noninvasive diagnosis and its potential to monitor treatment in vivo. We investigated the metabolites present in early and late stage cryptococcomas using in vivo 1H MRS in a murine model and evaluated changes in trehalose concentrations induced by disease progression and antifungal treatment. Animal data were compared to 1H and 13C MR spectra of Cryptococcus cultures and in vivo data from 2 patients with cryptococcomas in the brain. In vivo MRS allowed the noninvasive detection of high concentrations of trehalose in cryptococcomas and showed a comparable metabolic profile of cryptococcomas in the murine model and human cases. Trehalose concentrations correlated strongly with the fungal burden. Treatment studies in cultures and animal models showed that trehalose concentrations decrease following exposure to effective antifungal therapy. Although further cases need to be studied for clinical validation, this translational study indicates that the noninvasive MRS-based detection of trehalose is a promising marker for diagnosis and therapeutic follow-up of cryptococcomas.

Stabilization of recombinant d-Lactate dehydrogenase enzyme with trehalose: Response surface methodology and molecular dynamics simulation study

In this work, the effect of trehalose was investigated on the structural stability of the d-Lactate dehydrogenase (DLDH) enzyme. Initially, response surface methodology (RSM) was applied to optimize different process variables for the stabilization of DLDH using trehalose. The stabilization of DLDH with trehalose was examined under various experimental conditions, including trehalose concentration, pH, temperature, and incubation time. The effect of the processing parameters was tested using the RSM method and a central composite design (CCD) model. According to the ANOVA results, there was a close correlation between the predicted and experimental values of the response parameter. The optimum values of trehalose concentration, pH, temperature, and incubation time were found to be 1.25 M, 8, 30 °C, and 25 min, respectively, for achieving the maximum activity. Then, the kinetic and thermodynamic parameters of DLDH in the absence and presence of trehalose were examined. The DLDH half-life at 40 °C was 28.88 min, while, in the presence of trehalose, the enzyme had a longer half-life (33.01 min) at this temperature. Also, in the end, molecular dynamics (MD) simulations of the DLDH enzyme was performed at the optimum conditions to obtain fundamental insights into the conformational transitions of the DLDH enzyme in the absence and presence of trehalose.

The combination of trehalose and glycerol: an effective and non-toxic recipe for cryopreservation of human adipose-derived stem cells

BackgroundAdipose-derived stem cells (ADSCs) promote tissue regeneration and repair. Cryoprotective agents (CPAs) protect cells from cryodamage during cryopreservation. Safe and efficient cryopreservation of ADSCs is critical for cell-based therapy in clinical applications. However, most CPAs are used at toxic concentrations, limiting their clinical application.ObjectiveThe aim of this study is to develop a non-toxic xeno-free novel CPA aiming at achieving high-efficiency and low-risk ADSC cryopreservation.MethodsWe explored different concentrations of trehalose (0.3 M, 0.6 M, 1.0 M, and 1.25 M) and glycerol (10%, 20%, and 30% v/v) for optimization and evaluated and compared the outcomes of ADSCs cryopreservation between a combination of trehalose and glycerol and the commonly used CPA DMSO (10%) + FBS (90%). All samples were slowly frozen and stored in liquid nitrogen for 30 days. The effectiveness was evaluated by the viability, proliferation, migration, and multi-potential differentiation of the ADSCs after thawing.ResultsCompared with the groups treated with individual reagents, the 1.0 M trehalose (Tre) + 20% glycerol (Gly) group showed significantly higher efficiency in preserving ADSC activities after thawing, with better outcomes in both cell viability and proliferation capacity. Compared with the 10% DMSO + 90% FBS treatment, the ADSCs preserved in 1.0 M Tre + 20% Gly showed similar cell viability, surface markers, and multi-potential differentiation but a significantly higher migration capability. The results indicated that cell function preservation can be improved by 1.0 M Tre + 20% Gly.ConclusionsThe 1.0 M Tre + 20% Gly treatment preserved ADSCs with a higher migration capability than 10% DMSO + 90% FBS and with viability higher than that with trehalose or glycerol alone but similar to that with 10% DMSO + 90% FBS and fresh cells. Moreover, the new CPA achieves stemness and multi-potential differentiation similar to those in fresh cells. Our results demonstrate that 1.0 M Tre + 20% Gly can more efficiently cryopreserve ADSCs and is a non-toxic CPA that may be suitable for clinical applications.

Trehalose addition to a Tris-fructose egg yolk extender on quality of ram sperm preserved at 0 °C

The present study investigated the effects of various concentrations of trehalose in Tris-fructose egg yolk diluent on ram semen preservation at 0 ℃. Semen was collected by artificial vagina ejaculation from six rams of proven fertility. High-quality ejaculates were diluted with 0 (control), 5, 10, 15, and 20 mM trehalose of Tris-fructose egg yolk extender and control (tris-fructose egg yolk extender without trehalose), respectively. Then, the ejaculates were diluted to a concentration of 5×108 sperm/mL, cooled to 0 ℃ [...]

Is there a causal relationship between trehalose consumption and Clostridioides difficile infection?

Trehalose metabolism appears to play a role in the pathogenicity of some microbes. It has been claimed that trehalose consumption may be a risk factor for Clostridioides difficile infection (CDI), but the evidence for a causal link is contentious. Epidemic ribotypes of C. difficile harbour mutations or have acquired extra genes that mean these strains can utilize lower concentrations of bioavailable trehalose, providing a competitive metabolic advantage in some CDI animal models. By contrast, evidence has emerged to show that trehalose-induced microbiota changes can help protect/reduce CDI in other models. In addition, C. difficile trehalose metabolic variants are widespread among epidemic and nonepidemic ribotypes alike, and the occurrence of these trehalose variants was not associated with increase disease severity or mortality. Currently, there is no proven causal association between the incidence or severity of human CDI and the presence of trehalose metabolism variants. Furthermore, microbial metabolism reduces trehalose bioavailability, potentially removing this competitive advantage for C. difficile trehalose metabolism variants. Taken together, trehalose consumed as part of a normal diet has no increased risk of CDI.

MAL62 overexpression enhances uridine diphosphoglucose-dependent trehalose synthesis and glycerol metabolism for cryoprotection of baker\u2019s yeast in lean dough

BackgroundIn Saccharomyces cerevisiae, alpha-glucosidase (maltase) is a key enzyme in maltose metabolism. In addition, the overexpression of the alpha-glucosidase-encoding gene MAL62 has been shown to increase the freezing tolerance of yeast in lean dough. However, its cryoprotection mechanism is still not clear.ResultsRNA sequencing (RNA-seq) revealed that MAL62 overexpression increased uridine diphosphoglucose (UDPG)-dependent trehalose synthesis. The changes in transcript abundance were confirmed by quantitative reverse transcription–polymerase chain reaction (qRT-PCR) and enzyme activity assays. When the UDPG-dependent trehalose synthase activity was abolished, MAL62 overexpression failed to promote the synthesis of intracellular trehalose. Moreover, in strains lacking trehalose synthesis, the cell viability in the late phase of prefermentation freezing coupled with MAL62 overexpression was slightly reduced, which can be explained by the increase in the intracellular glycerol concentration. This result was consistent with the elevated transcription of glycerol synthesis pathway members.ConclusionsThe increased freezing tolerance by MAL62 overexpression is mainly achieved by the increased trehalose content via the UDPG-dependent pathway, and glycerol also plays an important role. These findings shed new light on the mechanism of yeast response to freezing in lean bread dough and can help to improve industrial yeast strains.

Pulsed electric field pre-treatment for enhanced bacterial survival after drying: Effect of carrier matrix and strain variability

Previous studies suggest that increased intracellular trehalose concentrations can result in increased robustness of probiotics and starter cultures after processing. We evaluated whether pulsed electric field (PEF) pre-treatment, resulting in increased intracellular trehalose concentrations, can lead to enhanced survival during spray drying and subsequent storage and what the effect of the carrier matrix during drying herein is on survival. The applied PEF pre-treatment resulted in increased survival of Lactobacillus plantarum WCFS1 after spray drying and subsequent storage in reconstituted skim milk (RSM), though not in the other evaluated carrier matrices. The same PEF pre-treatment in lactose instead of trehalose electroporation medium resulted also in an increased survival after spray drying in RSM. Further analysis of intracellular trehalose and lactose concentrations revealed that survival after spray drying cannot only be explained by intracellular trehalose and/or lactose concentrations. Experiments with other bacterial strains indicated that strain variability cannot be neglected when designing a process aimed at enhanced bacterial survival after processing. Overall, PEF pre-treatment is promising for enhancing survival of bacteria after drying and storage, though further understanding of the applicability is required for industrial application. Industrial relevance textProbiotics and starter cultures are very common in food industry. Survival of these cultures during drying processes is essential for their application. A pulsed electric field pre-treatment resulting in increased bacterial survival after spray drying and powder storage may contribute to more energy efficient production processes of dried bacterial cultures.

Temperature and presence of ethanol affect accumulation of intracellular trehalose in Lactobacillus plantarum WCFS1 upon pulsed electric field treatment

Pulsed electric field (PEF) treatment can be used to increase intracellular small molecule concentrations in bacteria, which can lead to enhanced robustness of these cells during further processing. In this study we investigated the effects of the PEF treatment temperature and the presence of 8% (v/v) ethanol in the PEF medium on cell survival, membrane fluidity and intracellular trehalose concentrations of Lactobacillus plantarum WCFS1. A moderate PEF treatment temperature of 21 °C resulted in a high cell survival combined with higher intracellular trehalose concentrations compared to a treatment at 10 and 35 °C. Interestingly, highest intracellular trehalose concentrations were observed upon supplementing the PEF medium with 8% ethanol, which resulted in more than a doubling in intracellular trehalose concentrations, while culture survival was retained. Overall, this study shows that treatment temperature and PEF medium optimization are important directions for improving molecule uptake upon PEF processing.

Characteristics and Expression Analyses of Trehalose-6-Phosphate Synthase Family in Prunus mume Reveal Genes Involved in Trehalose Biosynthesis and Drought Response.

Trehalose and its key synthase (trehalose-6-phosphate synthase, TPS) can improve the drought tolerance of plants. However, little is known about the roles of trehalose and the TPS family in Prunus mume response to drought. In our study, we discovered that the trehalose content in leaf, root, and stem tissues significantly increased in P. mume in response to drought. Therefore, the characteristics and functions of the TPS family are worth investigating in P. mume. We identified nine TPS family members in P. mume, which were divided into two sub-families and characterized by gene structure, promoter elements, protein conserved domains, and protein motifs. We found that the Hydrolase_3 domain and several motifs were highly conserved in Group II instead of Group I. The distinctions between the two groups may result from selective constraints, which we estimated by the dN/dS (ω) ratio. The ω values of all the PmTPS family gene pairs were evaluated as less than 1, indicating that purity selection facilitated their divergence. A phylogenetic tree was constructed using 92 TPSs from 10 Rosaceae species, which were further divided into five clusters. Based on evolutionary analyses, the five clusters of TPS family proteins mainly underwent varied purity selection. The expression patterns of PmTPSs under drought suggested that the TPS family played an important role in the drought tolerance of P. mume. Combining the expression patterns of PmTPSs and the trehalose content changes in leaf, stem, and root tissues under normal conditions and drought stress, we found that the PmTPS2 and PmTPS6 mainly function in the trehalose biosynthesis in P. mume. Our findings not only provide valuable information about the functions of trehalose and TPSs in the drought response of P. mume, but they also contribute to the future drought breeding of P. mume.

Regulation of Carbohydrate Metabolism by Trehalose-6-Phosphate Synthase 3 in the Brown Planthopper, Nilaparvata lugens.

Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) is one of the pests that harm rice. In this paper, a new trehalose-6-phosphate synthase gene, TPS3, was identified by transcriptome sequencing and gene cloning. To explore its role in the energy metabolism of N. lugens we examined the carbohydrate contents at different stages of development, the tissue expression of TPS, and some physiological and biochemical indicators by injecting dsTPS3 and dsTPSs (a proportional mixture of dsTPS1, dsTPS2, and dsTPS3). The glucose content at the fifth instar was significantly higher than that in the fourth instar and the adult stages. The trehalose and glycogen contents before molting were higher than those after molting. TPS1, TPS2, and TPS3 were expressed in the head, leg, wing bud, and cuticle, with the highest expression in the wing bud. In addition, compared with the control group, the glucose content increased significantly at 48 h after RNA interference, and the trehalose content decreased significantly after 72 h. qRT-PCR showed that the expression level of UGPase decreased significantly at 48 h after injection, whereas GS expression increased significantly at 48 h after injecting dsTPS3. After dsTPS injection, the expression levels of PPGM2, UGPase, GP, and GS increased significantly at 72 h. After interfering with the expression of TPS3 gene alone, UGPase expression decreased significantly at 48 h, and GS expression increased significantly at 72 h. Finally, combined with the digital gene expression and pathway analysis, 1439 and 1346 genes were upregulated, and 2127 and 1927 genes were downregulated in the dsTPS3 and dsTPSs groups, respectively. The function of most differential genes was concentrated in sugar metabolism, lipid metabolism, and amino acid metabolism. The results indicated that TPS3 plays a key role in the energy metabolism of N. lugens and confirmed that TPS3 is a feasible target gene for RNA interference in N. lugens. Simultaneously, they provide a theoretical basis for the development and utilization of TPS3 to control pests.

Cryoprotective enhancing effect of very low concentration of trehalose on the functions of primary rat hepatocytes

IntroductionCells have various applications in biomedical research. Cryopreservation is a cell-preservation technique that provides cells for such applications. After cryopreservation, sensitive cells, such as primary hepatocytes, suffer from low viability due to the physical damage caused by ice crystals, highlighting the need for better methods of cryopreservation to improve cell viability. Given the importance of effectively suppressing ice crystal formation to protect cellular structure, trehalose has attracted attention as cryoprotectant based on its ability to inhibit ice crystal formation; however, trehalose induces osmotic stress. Therefore, to establish a cell-cryopreservation technique, it is necessary to provide an optimal balance between the protective and damaging effects of trehalose.MethodsIn this study, we evaluated the effects of osmotic stress and ice crystal formation on the viability and function of primary rat hepatocytes at wide range of trehalose concentration.ResultsThere was no osmotic stress at very low concentrations (2.6 μM) of trehalose, and 2.6 μM trehalose drives the formation of finer ice crystals, which are less damaging to the cell membrane. Furthermore, we found that the number of viable hepatocytes after cryopreservation were 70% higher under the 2.6 μM trehalose-supplemented conditions than under the dimethyl sulfoxide-supplemented conditions. Moreover, non-cryopreserved cells and cells cryopreserved with trehalose showed comparable intracellular dehydrogenase activity.ConclusionsWe showed that trehalose at very low concentrations (2.6 μM) improved dramatically viability and liver function of hepatocyte after cryopreservation.

Knockdown of the Trehalose-6-Phosphate Synthase Gene Using RNA Interference Inhibits Synthesis of Trehalose and Increases Lethality Rate in Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Psyllidae).

Simple SummaryIn this study, we cloned and characterized a trehalose-6-phosphate synthase (TPS) gene from D. citri (DcTPS) for the first time. Meanwhile, we used RNA interference (RNAi) technology to efficiently disrupt DcTPS gene function in order to elucidate its role in the growth and development of D. citri. Our results suggest that dsRNA-mediated gene-specific silencing resulted in a strong reduction in relative expression of DcTPS and survival rate of nymphs, as well as an increase in malformation. This work was undertaken to establish a foundation for further research on the functions of D. citri trehalose-6-phosphate synthase. This will provide a new target for the control of D. citri in the field.Diaphorina citri Kuwayama is the vector of citrus “huanglongbing”, a citrus disease which poses a significant threat to the global citrus industry. Trehalose-6-phosphate synthase (TPS) plays an important role in the regulation of trehalose levels of insects, while its functions in D. citri are unclear. In this study, full-length cDNA sequences of the TPS gene from D. citri (DcTPS) were cloned and its expression patterns at various developmental stages were investigated. The results indicated that DcTPS mRNA was expressed at each developmental stage and the highest DcTPS expression was found in the fifth-instar nymphs of D. citri. Additionally, mortality and deformity of D. citri were observed after 24 and 48 h by feeding with three different dsRNA concentrations (20, 100 and 500 ng/μL). The results indicated that DcTPS expression was declined, and mortality and malformation in nymphs were increased via feeding with dsDcTPS. Moreover, the enzyme and trehalose content were decreased, while the content of glucose was significantly higher than that of untreated (control) individuals. This suggests that DcTPS might be vital for the growth and development of D. citri and further studies of the genes should be related to molting and metabolism for controlling D. citri.

Decreasing glycerol content by co-supplementation of trehalose and taxifolin hydrate in ram semen extender: Microscopic, oxidative stress, and gene expression analyses

This study aimed to evaluate the comparative effects of taxifolin hydrate and trehalose on the quality of frozen-thawed ram spermatozoa for the first time. Ejaculates collected from six mature rams were pooled, and divided to eight equal aliquots to extend them with different concentrations of glycerol (%5 and %3), taxifolin hydrate (10, 100, and 500 μM), and trehalose (60 mM) as eight groups (G5T0, G5T10, G5T100, G5T500, G3T0, G3T10, G3T100, and G3T500). After freeze-thawing process of cryopreservation, microscopic and oxidative stress parameters, and gene expression levels were investigated for understanding of possible impacts of taxifolin hydrate and trehalose. The study showed that G3T10 resulted in the highest post-thawed viability and mitochondrial activity. Moreover, all extenders with taxifolin hydrate reduced DNA fragmentation in comparison to G5T0, but DNA damage was prevented at the highest rate in presence of G5T10. The level of LPO significantly decreased in the groups G5T500 and G3T100, and the expression levels of NQO1, GCLC, and GSTP1 genes significantly increased in the groups G5T100, G5T500, G3T10, and G3T100 compared to the group G5T0. Finally, co-supplementation of tris-based extender having 3% glycerol with 60 mM trehalose and 10 μM taxifolin hydrate in cryopreservation extender may be recommended to improve the quality of post-thawed ram spermatozoa. However, further in vivo and in vitro studies are suggested to evaluate fertility rates of frozen-thawed ram spermatozoa co-supplemented with trehalose and taxifolin hydrate.

Effects of Gingerols on Yeast Growth and Metabolism of the Fermentation Process

In this paper, the effects of gingerol on yeast growth and metabolism of the fermentation process is investigated by measuring the minimum inhibitory concentration, growth curve, alcohol, residual sugar, pH, total acid, intracellular trehalose and glycerol in different stages of yeast fermentation. The results showed that the minimum inhibitory concentration (MIC) of gingerol was 6mg/mL. In the fermentation process, with the increase of the amount of gingerol, the yeast number, the alcohol of fermentation liquor and the Glucose-lowering rate were decreased, the fermentation was incomplete, pH was lower, total acidity was increased, and the content of trehalose and glycerol were increased. The inhibitory effect of gingerol amount on yeast was: 4 mg/mL>2 mg/mL>0.5 mg/mL>0 mg/mL (no gingerol was added). This showed that gingerol has an obvious inhibitory effect on the growth and fermentation of yeasts.