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In Escherichia coli, the disaccharide trehalose can be metabolized as a carbon source or be accumulated as an osmoprotectant under osmotic stress. In hypertonic environments, E. coli accumulates trehalose in the cell by synthesis from glucose mediated by the cytosolic enzymes OtsA and OtsB. Trehalose in the periplasm can be hydrolyzed into glucose by the periplasmic trehalase TreA. We have previously shown that a treA mutant of extraintestinal E. coli strain BEN2908 displayed increased resistance to osmotic stress by 0.6 M urea, and reduced production of type 1 fimbriae, reduced invasion of avian fibroblasts, and decreased bladder colonization in a murine model of urinary tract infection. Since loss of TreA likely results in higher periplasmic trehalose concentrations, we wondered if deletion of otsA and otsB genes, which would lead to decreased internal trehalose concentrations, would reduce resistance to stress by 0.6 M urea and promote type 1 fimbriae production. The BEN2908DotsBA mutant was sensitive to osmotic stress by urea, but displayed an even more pronounced reduction in production of type 1 fimbriae, with the consequent reduction in adhesion/invasion of avian fibroblasts and reduced bladder colonization in the murine urinary tract. The BEN2908DtreAotsBA mutant also showed a reduction in production of type 1 fimbriae, but in contrast to the DotsBA mutant, resisted better than the wild type in the presence of urea. We hypothesize that, in BEN2908, resistance to stress by urea would depend on the levels of periplasmic trehalose, but type 1 fimbriae production would be influenced by the levels of cytosolic trehalose. [ABSTRACT FROM AUTHOR]

Simple Summary: Due to issues with pesticide residues and resistance caused by traditional pesticides, the use of modified atmosphere storage technology has become increasingly popular. However, research has shown that prolonged exposure to high concentrations of CO2 for pest control in this technology can lead to insect resistance to hypoxia. Therefore, it is necessary to find out the resistance mechanism. This study identifies TcCYP6K1 and TcCYP9F2 as key factors in the response to high CO2 in Tribolium castaneum, suggesting that these genes may affect the resistance to high CO2 by influencing in the synthesis or breakdown of the carbohydrate metabolism pathways. These findings provide a theoretical basis for the combined use of novel nucleic acid pesticides and modified atmosphere treatment. Cytochrome P450 monooxygenases (CYP), crucial detoxification enzymes in insects, are involved in the metabolism of endogenous substances as well as the activation and degradation of exogenous compounds. In this study, T. castaneum was utilized to investigate the roles of TcCYP6K1 and TcCYP9F2 genes influencing in the trehalose metabolism pathway under high-CO2 stress. By predicting the functional sequences of TcCYP6K1 and TcCYP9F2 genes and analyzing their spatiotemporal expression patterns, it was discovered that both genes belong to the CYP3 group and exhibit high expression levels during the larval stage, decreasing during the pupal stage, while showing high expression in the fatty body, intestine, and malpighian tubules. Furthermore, following the knockdown of TcCYP6K1 and TcCYP9F2 genes in combination with treating larvae with 75% CO2, it was observed that larval mortality increased, and glycogen content significantly decreased, while trehalose content increased significantly. Additionally, membrane-bound trehalase enzyme activity declined, TPS gene expression was significantly upregulated, GS gene expression was significantly downregulated, and ATP content showed a marked decrease. In conclusion, CYP genes are critical responsive genes of T. castaneum to high CO2 levels, potentially impacting the insect's resistance to carbon dioxide through their involvement in the synthesis or breakdown of the carbohydrate metabolism pathway. These findings could serve as a theoretical basis for the utilization of novel pesticides in low-oxygen grain storage techniques and offer new insights for environmentally friendly pest control strategies in grain storage. [ABSTRACT FROM AUTHOR]

Sexual reproduction is prevalent in eukaryotic organisms and plays a critical role in the evolution of new traits and in the generation of genetic diversity. Environmental factors often have a direct impact on the occurrence and frequency of sexual reproduction in fungi. The regulatory effects of atmospheric relative humidity (RH) on sexual reproduction and pathogenesis in plant fungal pathogens and in soil fungi have been extensively investigated. However, the knowledge of how RH regulates the lifecycles of human fungal pathogens is limited. In this study, we report that low atmospheric RH promotes the development of mating projections and same-sex (homothallic) mating in the human fungal pathogen Candida albicans. Low RH causes water loss in C. albicans cells, which results in osmotic stress and the generation of intracellular reactive oxygen species (ROS) and trehalose. The water transporting aquaporin Aqy1, and the G-protein coupled receptor Gpr1 function as cell surface sensors of changes in atmospheric humidity. Perturbation of the trehalose metabolic pathway by inactivating trehalose synthase or trehalase promotes same-sex mating in C. albicans by increasing osmotic or ROS stresses, respectively. Intracellular trehalose and ROS signal the Hog1-osmotic and Hsf1-Hsp90 signaling pathways to regulate the mating response. We, therefore, propose that the cell surface sensors Aqy1 and Gpr1, intracellular trehalose and ROS, and the Hog1-osmotic and Hsf1-Hsp90 signaling pathways function coordinately to regulate sexual mating in response to low atmospheric RH conditions in C. albicans.

The impact of heavy metals on agricultural ecosystems has consistently been a topic of social concern. This study investigated the translocation of lead (Pb) along the soil – Vicia faba L. (Fabales: Fabaceae) – Megoura crassicauda (Hemiptera: Aphidoidea) – Harmonia axyridis (Coleoptera: Coccinellidae) system. Lead in soil could be transferred to broad bean, and the accumulation amount was highest in roots, followed by stems and leaves. Aphids and ladybirds could also accumulate lead through the food chain. Interestingly, the lead content of broad bean roots in the aphid feeding group was significantly higher than that in the non-aphid feeding group. Lead stress significantly reduced the germination rate and seedling height of broad bean, and inhibited root elongation. The expression levels of trehalase (TRE), trehalose-6-phosphate synthase (TPS), and vitellogenin (Vg), TRE activity, and carbohydrate content in aphids changed under lead treatment. The number of offspring produced by the second and fifth generation aphids was significantly reduced under lead treatment. Furthermore, high concentrations of lead treatment can prolong the development time of the 2nd and 3rd instar larvae of the ladybird. Feeding on aphids contaminated with lead can affect the survival of ladybirds. Our results further confirm the biological transfer of lead in the food chain and explore the adaptive mechanisms of aphids and ladybirds. These relevant results provide a theoretical basis for further exploring the molecular mechanism of lead homeostasis in plants and insects under lead stress. [ABSTRACT FROM AUTHOR]

Mycobacterium tuberculosis (Mtb) adapt to various host environments and utilize a variety of sugars and lipids as carbon sources. Among these sugars, maltose and trehalose, also play crucial role in bacterial physiology and virulence. However, some key enzymes involved in trehalose and maltose metabolism in Mtb are not yet known. Here we structurally and functionally characterized a conserved hypothetical gene Rv3400. We determined the crystal structure of Rv3400 at 1.7 Å resolution. The crystal structure revealed that Rv3400 adopts Rossmann fold and shares high structural similarity with haloacid dehalogenase family of proteins. Our comparative structural analysis suggested that Rv3400 could perform either phosphatase or pyrophosphatase or β‐phosphoglucomutase (β‐PGM) activity. Using biochemical studies, we further confirmed that Rv3400 performs β‐PGM activity and hence, Rv3400 encodes for β‐PGM in Mtb. Our data also confirm that Mtb β‐PGM is a metal dependent enzyme having broad specificity for divalent metal ions. β‐PGM converts β‐D‐glucose‐1‐phosphate to β‐D‐glucose‐6‐phosphate which is required for the generation of ATP and NADPH through glycolysis and pentose phosphate pathway, respectively. Using site directed mutagenesis followed by biochemical studies, we show that two Asp residues in the highly conserved DxD motif, D29 and D31, are crucial for enzyme activity. While D29A, D31A, D29E, D31E and D29N mutants lost complete activity, D31N mutant retained about 30% activity. This study further helps in understanding the role of β‐PGM in the physiology of Mtb. [ABSTRACT FROM AUTHOR]

In Escherichia coli, the disaccharide trehalose can be metabolized as a carbon source or be accumulated as an osmoprotectant under osmotic stress. In hypertonic environments, E. coli accumulates trehalose in the cell by synthesis from glucose mediated by the cytosolic enzymes OtsA and OtsB. Trehalose in the periplasm can be hydrolyzed into glucose by the periplasmic trehalase TreA. We have previously shown that a treA mutant of extraintestinal E. coli strain BEN2908 displayed increased resistance to osmotic stress by 0.6 M urea, and reduced production of type 1 fimbriae, reduced invasion of avian fibroblasts, and decreased bladder colonization in a murine model of urinary tract infection. Since loss of TreA likely results in higher periplasmic trehalose concentrations, we wondered if deletion of otsA and otsB genes, which would lead to decreased internal trehalose concentrations, would reduce resistance to stress by 0.6 M urea and promote type 1 fimbriae production. The BEN2908ΔotsBA mutant was sensitive to osmotic stress by urea, but displayed an even more pronounced reduction in production of type 1 fimbriae, with the consequent reduction in adhesion/invasion of avian fibroblasts and reduced bladder colonization in the murine urinary tract. The BEN2908ΔtreAotsBA mutant also showed a reduction in production of type 1 fimbriae, but in contrast to the ΔotsBA mutant, resisted better than the wild type in the presence of urea. We hypothesize that, in BEN2908, resistance to stress by urea would depend on the levels of periplasmic trehalose, but type 1 fimbriae production would be influenced by the levels of cytosolic trehalose.

Cytochrome P450 monooxygenases (CYP), crucial detoxification enzymes in insects, are involved in the metabolism of endogenous substances as well as the activation and degradation of exogenous compounds. In this study, T. castaneum was utilized to investigate the roles of TcCYP6K1 and TcCYP9F2 genes influencing in the trehalose metabolism pathway under high-CO2 stress. By predicting the functional sequences of TcCYP6K1 and TcCYP9F2 genes and analyzing their spatiotemporal expression patterns, it was discovered that both genes belong to the CYP3 group and exhibit high expression levels during the larval stage, decreasing during the pupal stage, while showing high expression in the fatty body, intestine, and malpighian tubules. Furthermore, following the knockdown of TcCYP6K1 and TcCYP9F2 genes in combination with treating larvae with 75% CO2, it was observed that larval mortality increased, and glycogen content significantly decreased, while trehalose content increased significantly. Additionally, membrane-bound trehalase enzyme activity declined, TPS gene expression was significantly upregulated, GS gene expression was significantly downregulated, and ATP content showed a marked decrease. In conclusion, CYP genes are critical responsive genes of T. castaneum to high CO2 levels, potentially impacting the insect’s resistance to carbon dioxide through their involvement in the synthesis or breakdown of the carbohydrate metabolism pathway. These findings could serve as a theoretical basis for the utilization of novel pesticides in low-oxygen grain storage techniques and offer new insights for environmentally friendly pest control strategies in grain storage.

Simple Summary: Trehalose plays crucial roles in the cold tolerance of insects. Trehalose-6-phosphate synthase (TPS) is an important enzyme involved in trehalose synthesis. TPS genes have been demonstrated to be involved in cold-resistant physiological processes. Lissorhoptrus oryzophilus is an important invasive pest of rice in China. To gain insight into the function of TPS in rapid cold hardening (RCH), we cloned and characterized the TPS gene of L. oryzophilus (LoTPS). Next, we examined changes in gene expression and trehalose levels under low temperature after RCH treatment. We found that LoTPS was a fused gene with conserved TPS and trehalose-6-phosphate phosphatase (TPP) domains. As expected, RCH increased the survival rate of L. oryzophilus adults under low temperature. Furthermore, it led to an increase in TPS gene expression and trehalose content. However, RCH efficiency disappeared when the LoTPS gene was RNA-interfered, causing no significant increase in the survival rate, TPS gene expression or trehalose level. This study demonstrates the importance of TPS in enhancing cold tolerance through RCH. The TPS gene regulates trehalose synthesis and accumulation in adults, thus improving their survival under low temperatures. Our findings contribute to a better understanding of the cold tolerance mechanisms and invasiveness of L. oryzophilus. Rapid cold hardening (RCH) is known to rapidly enhance the cold tolerance of insects. Trehalose has been demonstrated to be a cryoprotectant in Lissorhoptrus oryzophilus, an important invasive pest of rice in China. Trehalose synthesis mainly occurs through the Trehalose-6-phosphate synthase (TPS)/trehalose-6-phosphate phosphatase (TPP) pathway in insects. In this study, the TPS gene from L. oryzophilus (LoTPS) was cloned and characterized for the first time. Its expression and trehalose content changes elicited by RCH were investigated. Our results revealed that RCH not only increased the survival rate of adults but also upregulated the expression level of LoTPS and increased the trehalose content under low temperature. We hypothesized that upregulated LoTPS promoted trehalose synthesis and accumulation to protect adults from low-temperature damage. To further verify the function of the LoTPS gene, we employed RNA interference (RNAi) technology. Our findings showed that RCH efficiency disappeared and the survival rate did not increase when the adults were fed dsRNA of LoTPS. Additionally, inhibiting LoTPS expression resulted in no significant difference in trehalose content between the RCH and non-RCH treatments. Furthermore, the expression patterns of trehalose transporter (TRET) and trehalase (TRE) were also affected. Collectively, these results indicate the critical role of LoTPS in L. oryzophilus cold resistance after RCH induction. LoTPS can enhance survival ability by regulating trehalose metabolism. These findings contribute to further understanding the role of TPS in insect cold resistance and the invasiveness of L. oryzophilus. Moreover, RNAi of LoTPS opens up possibilities for novel control strategies against L. oryzophilus in the future. [ABSTRACT FROM AUTHOR]

BACKGROUND: Tomato chlorosis virus (ToCV) is a semi‐persistent plant virus that is primarily transmitted by the whitefly Bemisia tabaci (Hemiptera: Aleyrodidae). It causes a serious disease that lowers tomato yield. Insulin‐like peptide (ILP), an insulin homolog, regulates trehalose metabolism in a variety of insects. In a previous study, we discovered that trehalose metabolism is required for whiteflies to transmit ToCV effectively. Furthermore, transcriptome sequencing revealed that the BtILP7 gene was highly expressed in B. tabaci infected with ToCV. Therefore, the whitefly ILP7 gene may facilitate the transmission of ToCV and be an attractive target for the control of whiteflies and subsequently ToCV. RESULTS: The ToCV content in B. tabaci MED was found to be correlated with BtILP7 gene expression. Subsequent RNA interference (RNAi) of the BtILP7 gene had a significant impact on B. tabaci MED's trehalose metabolism and reproductive capacity, as well as ability to transmit ToCV. CONCLUSIONS: These results indicate that the BtILP7 gene was closely related to ToCV transmission by regulating trehalose metabolism and reproduction behavior, thus providing a secure and environmentally friendly management strategy for the control of whiteflies and ToCV‐caused disease. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Introduction: Spodoptera frugiperda is an omnivorous agricultural pest which is great dangerous for grain output. Methods: In order to investigate the effects of potential trehalase inhibitors, ZKPI-5 and ZK-PI-9, on the growth and development of S. frugiperda, and to identify new avenues for S. frugiperda control, we measured the content of the trehalose, glucose, glycogen and chitin, enzyme activity, and gene expression levels in trehalose and chitin metabolism of S. frugiperda. Besides, their growth and development were also observed. Results: The results showed that ZK-PI-9 significantly reduced trehalase activity and ZK-PI-5 significantly reduced membraned-bound trehalase activity. Moreover, ZK-PI-5 inhibited the expression of SfTRE2, SfCHS2, and SfCHT, thus affecting the chitin metabolism. In addition, the mortality of S. frugiperda in pupal stage and eclosion stage increased significantly after treatment with ZKPI-5 and ZK-PI-9, which affected their development stage and caused death phenotype (abnormal pupation and difficulty in breaking pupa). Discussion: These results have provided a theoretical basis for the application of trehalase inhibitors in the control of agricultural pests to promote future global grain yield. [ABSTRACT FROM AUTHOR]

Rapid cold hardening (RCH) is known to rapidly enhance the cold tolerance of insects. Trehalose has been demonstrated to be a cryoprotectant in Lissorhoptrus oryzophilus, an important invasive pest of rice in China. Trehalose synthesis mainly occurs through the Trehalose-6-phosphate synthase (TPS)/trehalose-6-phosphate phosphatase (TPP) pathway in insects. In this study, the TPS gene from L. oryzophilus (LoTPS) was cloned and characterized for the first time. Its expression and trehalose content changes elicited by RCH were investigated. Our results revealed that RCH not only increased the survival rate of adults but also upregulated the expression level of LoTPS and increased the trehalose content under low temperature. We hypothesized that upregulated LoTPS promoted trehalose synthesis and accumulation to protect adults from low-temperature damage. To further verify the function of the LoTPS gene, we employed RNA interference (RNAi) technology. Our findings showed that RCH efficiency disappeared and the survival rate did not increase when the adults were fed dsRNA of LoTPS. Additionally, inhibiting LoTPS expression resulted in no significant difference in trehalose content between the RCH and non-RCH treatments. Furthermore, the expression patterns of trehalose transporter (TRET) and trehalase (TRE) were also affected. Collectively, these results indicate the critical role of LoTPS in L. oryzophilus cold resistance after RCH induction. LoTPS can enhance survival ability by regulating trehalose metabolism. These findings contribute to further understanding the role of TPS in insect cold resistance and the invasiveness of L. oryzophilus. Moreover, RNAi of LoTPS opens up possibilities for novel control strategies against L. oryzophilus in the future.

Trehalose metabolism is related to the sclerotial development of Rhizoctonia solani AG-1 IA, the causal agent of rice sheath blight (RSB). Here, we further elucidated the functions of three genes Rstre, Rstps1 and Rstpp that encode three key enzymes trehalase (TRE), alpha, alpha-trehalose- phosphate synthase (TPS1) and trehalose 6-phosphate phosphatase (TPP) in the sclerotial development of R. solani AG-1 IA. Due to the lack of a stable genetic transformation system for R. solani, the heterologous expression of these three genes in Pichia pastoris GS115 was performed. The results showed that reactive oxygen species (ROS) contents and enzyme activities in R. solani decreased significantly in the treatments of the fermentation broths of Rstps1 and Rstpp transformants, and that in the treatment of the fermentation broth of Rstre transformant visibly increased. Furthermore, the fermentation broths of the transformants of all the three genes were added to potato dextrose agar (PDA) medium for the cultivation of R. solani, as a result, the dry weight of sclerotia in each PDA plate containing the fermentation broths of Rstps1 and Rstpp transformants significantly increased compared with the control, and that of Rstre transformant obviously decreased. Finally, 178 proteins were found to interact with RSTPS1, and 16 of them were associated with ROS. Taken together, the findings suggest that all these three genes related to trehalose metabolism play important roles in the sclerotial development of R. solani AG-1 IA, and can be used as new targets for the development of novel high-efficiency fungicides for the controlling of RSB.

In plants, the trehalose biosynthetic pathway plays key roles in the regulation of carbon allocation and stress adaptation. Engineering of the pathway holds great promise to increase the stress resilience of crop plants. The synthesis of trehalose proceeds by a two-step pathway in which a trehalose-phosphate synthase (TPS) uses UDP-glucose and glucose-6-phosphate to produce trehalose-6 phosphate (T6P) that is subsequently dephosphorylated by trehalose-6 phosphate phosphatase (TPP). While plants usually do not accumulate high amounts of trehalose, their genome encodes large families of putative trehalose biosynthesis genes, with many members lacking obvious enzymatic activity. Thus, the function of putative trehalose biosynthetic proteins in plants is only vaguely understood. To gain a deeper insight into the role of trehalose biosynthetic proteins in crops, we assessed the enzymatic activity of the TPS/TPP family from tomato (Solanum lycopersicum L.) and investigated their expression pattern in different tissues as well as in response to temperature shifts. From the 10 TPS isoforms tested, only the 2 proteins belonging to class I showed enzymatic activity, while all 5 TPP isoforms investigated were catalytically active. Most of the TPS/TPP family members showed the highest expression in mature leaves, and promoter–reporter gene studies suggest that the two class I TPS genes have largely overlapping expression patterns within the vasculature, with only subtle differences in expression in fruits and flowers. The majority of tomato TPS/TPP genes were induced by heat stress, and individual family members also responded to cold. This suggests that trehalose biosynthetic pathway genes could play an important role during temperature stress adaptation. In summary, our study represents a further step toward the exploitation of the TPS and TPP gene families for the improvement of tomato stress resistance. [ABSTRACT FROM AUTHOR]

Spodoptera frugiperda has emerged as a major invasive pest worldwide. The utilization of chemical pesticides not only poses numerous ecological concerns but also fosters resistance in S. frugiperda. In this study, we designed and synthesized three novel thiothiazolidinone compounds (6a, 7b, and 7e) and incorporated innovative thiothiazolidinone structural elements into the piperine skeleton. Treatment with compounds 6a and 7e resulted in the blackening and agglomeration of oviduct eggs within the ovaries of certain female moths, impeding the release of normal eggs. The levels of vitellogenin and vitellogenin receptor, along with three trehalase inhibitors, exhibited a dynamic equilibrium state, leading to no discernible change in egg production but a notable increase in the generation of low-hatching-rate egg fragments. Compared with the injection of 2%DMSO, the eclosion rate of 6a injection was significantly decreased, as followed the spawning time and longevity were prolonged or significantly prolonged in the trehalase inhibitors of 6a, 7b, and 7e. We aimed to investigate the regulatory impacts of three new pepper thiothiazolidinone compounds on the reproduction of S. frugiperda , and to authenticate the efficacy of novel alginase inhibitors in inhibiting the reproduction of S. frugiperda. This research endeavors to aid in the identification of efficient and steadfast trehalase inhibitors, thereby expediting the research and development of potent biological pesticides. [Display omitted] • We designed and synthesized three novel thiothiazolidinone compounds (6a, 7b, and 7e). • The regulatory impacts of three new pepper thiothiazolidinone compounds on the reproduction of Spodoptera frugiperda. • Trehalase inhibitors appear to diminish the hatching rate of eggs and suppress the reproduction of Spodoptera frugiperda. • This research can help expedite the development of potent biological pesticides. [ABSTRACT FROM AUTHOR]

The effect of adding trehalose in the culture medium on Lactiplantibacillus plantarum LIP-1 was investigated during spray- and freeze-drying. Although previous studies reported that the enhancement of bacterial resistance is due to intracellular trehalose accumulation, our study revealed that it was related to trehalose metabolism by the strain, and not accumulation. The underlying mechanisms were mainly related to the activation of l -glutamic acid and cysteine metabolic pathways during trehalose metabolism. First, murL , murD , and vanY in the l -glutamic acid metabolic pathway were significantly upregulated, increasing peptidoglycan synthesis and thus improving the cell wall integrity during drying process. Second, gshA in the cysteine metabolic pathway was upregulated, increasing intracellular glutathione content, enhancing antioxidant capacity, and thereby reducing the degree of cell membrane damage during drying process. Third, alkaline substances produced during l -glutamic acid and cysteine metabolisms increased the intracellular pH and reduced the degree of DNA damage caused by acid stress. [ABSTRACT FROM AUTHOR]

High carbon dioxide concentrations can effectively control most storage pests. To estimate the toxicity effect of high concentrations of CO2, four different concentrations of CO2 (25% CO2, 50% CO2, 75% CO2, and 95% CO2) were used to treat Tribolium castaneum, and the biochemical (carbohydrate content and gene expression level) and physiological (mortality, pupation, eclosion rate, and weight) features of insects submitted to different treatments with CO2 were evaluated. The T. castaneum mortality rate was 50% in approximately 2 days when exposed to a treatment with 95% CO2. When the CO2 concentration exceeded 75%, the pupation rate and eclosion rate of T. castaneum seriously declined. Higher than 25% CO2 concentrations resulted in a lower weight and shrunken body size of T. castaneum. It was further found that different CO2 concentration treatments all influenced the levels of the three carbohydrate contents in T. castaneum. In addition, according to the detection of trehalose metabolism pathway-related genes, T. castaneum mainly responds to stress factors via high expression of TPS, TRE1-2, and TRE1-3. Our results enrich the evaluation of the toxicity effect of CO2 treatment on grain storage pests, providing a basis for further improving the method of regulating grain storage to control insect pests. [ABSTRACT FROM AUTHOR]

High dietary sugar (HDS), a contemporary dietary concern due to excessive intake of added sugars and carbohydrates, escalates the risk of metabolic disorders and concomitant cancers. However, the molecular mechanisms underlying HDS-induced cancer progression are not completely understood. We found that phosphoenolpyruvate carboxykinase 1 (PEPCK1), a pivotal enzyme in gluconeogenesis, is paradoxically upregulated in tumors by HDS, but not by normal dietary sugar (NDS), during tumor progression. Targeted knockdown of pepck1, but not pepck2, specifically in tumor tissue in Drosophila in vivo, not only attenuates HDS-induced tumor growth but also significantly improves the survival of Ras/Src tumor-bearing animals fed HDS. Interestingly, HP1a-mediated heterochromatin interacts directly with the pepck1 gene and downregulates pepck1 gene expression in wild-type Drosophila. Mechanistically, we demonstrated that, under HDS conditions, pepck1 knockdown reduces both wingless and TOR signaling, decreases evasion of apoptosis, reduces genome instability, and suppresses glucose uptake and trehalose levels in tumor cells in vivo. Moreover, rational pharmacological inhibition of PEPCK1, using hydrazinium sulfate, greatly improves the survival of tumor-bearing animals with pepck1 knockdown under HDS. This study is the first to show that elevated levels of dietary sugar induce aberrant upregulation of PEPCK1, which promotes tumor progression through altered cell signaling, evasion of apoptosis, genome instability, and reprogramming of carbohydrate metabolism. These findings contribute to our understanding of the complex relationship between diet and cancer at the molecular, cellular, and organismal levels and reveal PEPCK1 as a potential target for the prevention and treatment of cancers associated with metabolic disorders., (© 2024. The Author(s).)

Competing Interests: Conflict of interest statement. None declared.

Trehalose 6-phosphate (Tre6P) is an essential signal metabolite that regulates the level of sucrose, linking growth and development to the metabolic status. We hypothesized that Tre6P plays a role in mediating the regulation of gene expression by sucrose. To test this, we performed transcriptomic profiling on Arabidopsis (Arabidopsis thaliana) plants that expressed a bacterial TREHALOSE 6-PHOSPHATE SYNTHASE (TPS) under the control of an ethanol-inducible promoter. Induction led to a 4-fold rise in Tre6P levels, a concomitant decrease in sucrose, significant changes (FDR ≤ 0.05) of over 13,000 transcripts, and 2-fold or larger changes of over 5,000 transcripts. Comparison with nine published responses to sugar availability allowed some of these changes to be linked to the rise in Tre6P, while others were probably due to lower sucrose or other indirect effects. Changes linked to Tre6P included repression of photosynthesis-related gene expression and induction of many growth-related processes including ribosome biogenesis. About 500 starvation-related genes are known to be induced by SUCROSE-NON-FERMENTING-1-RELATED KINASE 1 (SnRK1). They were largely repressed by Tre6P in a manner consistent with SnRK1 inhibition by Tre6P. SnRK1 also represses many genes that are involved in biosynthesis and growth. These responded to Tre6P in a more complex manner, pointing toward Tre6P interacting with other C-signaling pathways. Additionally, elevated Tre6P modified the expression of genes encoding regulatory subunits of the SnRK1 complex and TPS class II and FCS-LIKE ZINC FINGER proteins that are thought to modulate SnRK1 function and genes involved in circadian, TARGET OF RAPAMYCIN, light, abscisic acid, and other hormone signaling., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists.)

Mangroves grow in tropical/subtropical intertidal habitats with extremely high salt tolerance. Trehalose and trehalose-6-phosphate (T6P) have an alleviating function against abiotic stress. However, the roles of trehalose in the salt tolerance of salt-secreting mangrove Avicennia marina is not documented. Here, we found that trehalose was significantly accumulated in A. marina under salt treatment. Furthermore, exogenous trehalose can enhance salt tolerance by promoting the Na + efflux from leaf salt gland and root to reduce the Na + content in root and leaf. Subsequently, eighteen trehalose-6-phosphate synthase (AmTPS) and 11 trehalose-6-phosphate phosphatase (AmTPP) genes were identified from A. marina genome. Abscisic acid (ABA) responsive elements were predicted in AmTPS and AmTPP promoters by cis-acting elements analysis. We further identified AmTPS9A, as an important positive regulator, that increased the salt tolerance of AmTPS9A-overexpressing Arabidopsis thaliana by altering the expressions of ion transport genes and mediating Na + efflux from the roots of transgenic A. thaliana under NaCl treatments. In addition, we also found that ABA could promote the accumulation of trehalose, and the application of exogenous trehalose significantly promoted the biosynthesis of ABA in both roots and leaves of A. marina. Ultimately, we confirmed that AmABF2 directly binds to the AmTPS9A promoter in vitro and in vivo. Taken together, we speculated that there was a positive feedback loop between trehalose and ABA in regulating the salt tolerance of A. marina. These findings provide new understanding to the salt tolerance of A. marina in adapting to high saline environment at trehalose and ABA aspects., (© 2024 Society for Experimental Biology and John Wiley & Sons Ltd.)

Sweet potato [Ipomoea batatas (L.) Lam], the crop with the seventh highest annual production globally, is susceptible to various adverse environmental influences, and the study of stress-resistant genes is important for improving its tolerance to abiotic stress. The enzyme trehalose-6-phosphate synthase (TPS) is indispensable in the one pathway for synthesizing trehalose in plants. TPS is known to participate in stress response in plants, but information on TPS in sweet potato is limited. This study produced the N-terminal truncated IbTPS1 gene (△NIbTPS1) overexpression lines of Arabidopsis thaliana and sweet potato. Following salt and mannitol-induced drought treatment, the germination rate, root elongation, and fresh weight of the transgenic A. thaliana were significantly higher than that in the wild type. Overexpression of △NIbTPS1 elevated the photosynthetic efficiency (Fv/Fm) and the activity of superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase in sweet potato during drought and salt treatments, while reducing malondialdehyde and O 2 ∙- contents, although expression of the trehalose-6-phosphate phosphatase gene IbTPP and trehalose concentrations were not affected. Thus, overexpressing the △NIbTPS1 gene can improve the stress tolerance of sweet potato to drought and salt by enhancing the photosynthetic efficiency and antioxidative enzyme system. These results will contribute to understand the functions of the △NIbTPS1 gene and trehalose in the response mechanism of higher plants to abiotic stress., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Real-time tracking of intracellular carbohydrates remains challenging. While click chemistry allows bio-orthogonal tagging with fluorescent probes, the reaction permanently alters the target molecule and only allows a single snapshot. Here, we demonstrate click-free mid-infrared photothermal (MIP) imaging of azide-tagged carbohydrates in live cells. Leveraging the micromolar detection sensitivity for 6-azido-trehalose (TreAz) and the 300-nm spatial resolution of MIP imaging, the trehalose recycling pathway in single mycobacteria, from cytoplasmic uptake to membrane localization, is directly visualized. A peak shift of azide in MIP spectrum further uncovers interactions between TreAz and intracellular protein. MIP mapping of unreacted azide after click reaction reveals click chemistry heterogeneity within a bacterium. Broader applications of azido photothermal probes to visualize the initial steps of the Leloir pathway in yeasts and the newly synthesized glycans in mammalian cells are demonstrated.

Trehalose synthase (TreS) catalyzes the reversible interconversion of maltose to trehalose, playing a vital role in trehalose production. Understanding the catalytic mechanism of TreS is crucial for optimizing the enzyme activity and enhancing its suitability for industrial applications. Here, we report the crystal structures of both the wild type and the E324D mutant of Deinococcus radiodurans trehalose synthase in complex with the trehalose analogue, validoxylamine A. By employing structure-guided mutagenesis, we identified N253, E320, and E324 as crucial residues within the +1 subsite for isomerase activity. Based on these complex structures, we propose the catalytic mechanism underlying the reversible interconversion of maltose to trehalose. These findings significantly advance our comprehension of the reaction mechanism of TreS.

Background: Chromium (Cr) toxicity significantly threatens agricultural ecosystems worldwide, adversely affecting plant growth and development and reducing crop productivity. Trehalose, a non-reducing sugar has been identified as a mitigator of toxic effects induced by abiotic stressors such as drought, salinity, and heavy metals. The primary objective of this study was to investigate the influence of exogenously applied trehalose on maize plants exposed to Cr stress., Results: Two maize varieties, FH-1046 and FH-1453, were subjected to two different Cr concentrations (0.3 mM, and 0.5 mM). The results revealed significant variations in growth and biochemical parameters for both maize varieties under Cr-induced stress conditions as compared to the control group. Foliar application of trehalose at a concentration of 30 mM was administered to both maize varieties, leading to a noteworthy reduction in the detrimental effects of Cr stress. Notably, the Cr (0.5 mM) stress more adversely affected the shoot length more than 0.3mM of Cr stress. Cr stress (0.5 mM) significantly reduced the shoot length by 12.4% in FH-1046 and 24.5% in FH-1453 while Trehalose increased shoot length by 30.19% and 4.75% in FH-1046 and FH-1453 respectively. Cr stress significantly constrained growth and biochemical processes, whereas trehalose notably improved plant growth by reducing Cr uptake and minimizing oxidative stress caused by Cr. This reduction in oxidative stress was evidenced by decreased production of proline, SOD, POD, MDA, H 2 O 2 , catalase, and APX. Trehalose also enhanced photosynthetic activities under Cr stress, as indicated by increased values of chlorophyll a, b, and carotenoids. Furthermore, the ameliorative potential of trehalose was demonstrated by increased contents of proteins and carbohydrates and a decrease in Cr uptake., Conclusions: The study demonstrates that trehalose application substantially improved growth and enhanced photosynthetic activities in both maize varieties. Trehalose (30 mM) significantly increased the plant biomass, reduced ROS production and enhanced resilience to Cr stress even at 0.5 mM., (© 2024. The Author(s).)

Background: Saccharomyces cerevisiae is susceptible to high-sugar stress in the production of bioethanol, wine and bread. Calcium signal is widely involved in various physiological and metabolic activities of cells. The present study aimed to explore the effects of Ca 2+ signal on the antioxidant mechanism of yeast during high-sugar fermentation., Results: Compared to yeast without available Ca 2+ , yeast in the high glucose with Ca 2+ group had higher dry weight, higher ethanol output at 12 and 24 h and higher glycerol output at 24 and 36 h. During the whole growth process, the trehalose synthesis capacity of yeast in the high glucose with Ca 2+ group was lower and intracellular reactive oxygen species content was higher compared to yeast without available Ca 2+ . Intracellular malondialdehyde content of yeast under high glucose with Ca 2+ was significantly lower than yeast under high glucose without available Ca 2+ except for 6 h. The superoxide dismutase and catalase activities of yeast and glutathione content were higher in the high glucose with Ca 2+ group compared to yeast in high glucose without available Ca 2+ . The expression levels of SOD1, GSH1, GPX2 genes were higher for high glucose without available Ca 2+ at 6 h, while yeast in the high glucose with Ca 2+ group had a higher expression of antioxidant-related genes except SOD1 and CTT1 at 12 h. The expression levels of antioxidant-related genes of yeast for high glucose with Ca 2+ were higher at 24 h, and those of genes except SOD1 of yeast in the high glucose with Ca 2+ group were higher at 36 h., Conclusion: High-glucose stress limited the growth of yeast, while a moderate extracellular Ca 2+ signal could improve the antioxidant capacity of yeast in a high-glucose environment by regulating protectant metabolism and enhancing the antioxidant enzyme activity and expression of antioxidant genes in a high-sugar environment. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Escherichia coli Nissle 1917 (EcN) is one of the most widely used probiotics to treat gastrointestinal diseases. Recently, many studies have engineered EcN to release therapeutic proteins to treat specific diseases. However, because EcN exhibits intestinal metabolic activities, it is difficult to predict outcomes after administration. In silico and fermentation profiles revealed mucin metabolism of EcN. Multiomics revealed that fucose metabolism contributes to the intestinal colonization of EcN by enhancing the synthesis of flagella and nutrient uptake. The multiomics results also revealed that excessive intracellular trehalose synthesis in EcN, which is responsible for galactose metabolism, acts as a metabolic bottleneck, adversely affecting growth. To improve the ability of EcN to metabolize galactose, otsAB genes for trehalose synthesis were deleted, resulting in the ΔotsAB strain; the ΔotsAB strain exhibited a 1.47-fold increase in the growth rate and a 1.37-fold increase in the substrate consumption rate relative to wild-type EcN.

Invasive fungal diseases are a major threat to human health, resulting in more than 1.5 million annual deaths worldwide. The arsenal of antifungal therapeutics remains limited and is in dire need of drugs that target additional biosynthetic pathways that are absent from humans. One such pathway involves the biosynthesis of trehalose. Trehalose is a disaccharide that is required for pathogenic fungi to survive in their human hosts. In the first step of trehalose biosynthesis, trehalose-6-phosphate synthase (Tps1) converts UDP-glucose and glucose-6-phosphate to trehalose-6-phosphate. Here, we report the structures of full-length Cryptococcus neoformans Tps1 (CnTps1) in unliganded form and in complex with uridine diphosphate and glucose-6-phosphate. Comparison of these two structures reveals significant movement toward the catalytic pocket by the N terminus upon ligand binding and identifies residues required for substrate binding, as well as residues that stabilize the tetramer. Intriguingly, an intrinsically disordered domain (IDD), which is conserved among Cryptococcal species and closely related basidiomycetes, extends from each subunit of the tetramer into the "solvent" but is not visible in density maps. We determined that the IDD is not required for C. neoformans Tps1-dependent thermotolerance and osmotic stress survival. Studies with UDP-galactose highlight the exquisite substrate specificity of CnTps1. In toto, these studies expand our knowledge of trehalose biosynthesis in Cryptococcus and highlight the potential of developing antifungal therapeutics that disrupt the synthesis of this disaccharide or the formation of a functional tetramer and the use of cryo-EM in the structural characterization of CnTps1-ligand/drug complexes., Competing Interests: Competing interests statement:The authors declare no competing interest.

Organisms use organic molecules called osmolytes to adapt to environmental conditions. In vitro studies indicate that osmolytes thermally stabilize proteins, but mechanisms are controversial, and systematic studies within the cellular milieu are lacking. We analyzed Escherichia coli and human protein thermal stabilization by osmolytes in situ and across the proteome. Using structural proteomics, we probed osmolyte effects on protein thermal stability, structure and aggregation, revealing common mechanisms but also osmolyte- and protein-specific effects. All tested osmolytes (trimethylamine N-oxide, betaine, glycerol, proline, trehalose and glucose) stabilized many proteins, predominantly via a preferential exclusion mechanism, and caused an upward shift in temperatures at which most proteins aggregated. Thermal profiling of the human proteome provided evidence for intrinsic disorder in situ but also identified potential structure in predicted disordered regions. Our analysis provides mechanistic insight into osmolyte function within a complex biological matrix and sheds light on the in situ prevalence of intrinsically disordered regions., (© 2024. The Author(s).)

Tardigrades are unique among animals in their resistance to dehydration, mainly due to anhydrobiosis and tun formation. They are also very resistant to high-energy radiation, low and high temperatures, low and high pressure, and various chemical agents, Interestingly, they are resistant to ionizing radiation both in the hydrated and dehydrated states to a similar extent. They are able to survive in the cosmic space. Apparently, many mechanisms contribute to the resistance of tardigrades to harmful factors, including the presence of trehalose (though not common to all tardigrades), heat shock proteins, late embryogenesis-abundant proteins, tardigrade-unique proteins, DNA repair proteins, proteins directly protecting DNA (Dsup and TDR1), and efficient antioxidant system. Antioxidant enzymes and small-molecular-weight antioxidants are an important element in the tardigrade resistance. The levels and activities of many antioxidant proteins is elevated by anhydrobiosis and UV radiation; one explanation for their induction during dehydration is provided by the theory of "preparation for oxidative stress", which occurs during rehydration. Genes coding for some antioxidant proteins are expanded in tardigrades; some genes (especially those coding for catalases) were hypothesized to be of bacterial origin, acquired by horizontal gene transfer. An interesting antioxidant protein found in tardigrades is the new Mn-dependent peroxidase.

Desert strains of the genus Chroococcidiopsis are among the most desiccation-resistant cyanobacteria capable of anhydrobiosis. The accumulation of two sugars, sucrose and trehalose, facilitates the entrance of anhydrobiotes into a reversible state of dormancy by stabilizing cellular components upon water removal. This study aimed to evaluate, at the atomistic level, the role of trehalose in desiccation resistance by using as a model system the 30S ribosomal subunit of the desert cyanobacterium Chroococcidiopsis sp. 029. Molecular dynamic simulations provided atomistic evidence regarding its protective role on the 30S molecular structure. Trehalose forms an enveloping shell around the ribosomal subunit and stabilizes the structures through a network of direct interactions. The simulation confirmed that trehalose actively interacts with the 30S ribosomal subunit and that, by replacing water molecules, it ensures ribosomal structural integrity during desiccation, thus enabling protein synthesis to be carried out upon rehydration.

Syntaxin-binding protein 1 (STXBP1) is a presynaptic protein that plays important roles in synaptic vesicle docking and fusion. STXBP1 haploinsufficiency causes STXBP1 encephalopathy (STXBP1-E), which encompasses neurological disturbances including epilepsy, neurodevelopmental disorders, and movement disorders. Most patients with STXBP1-E present with regression and movement disorders in adulthood, highlighting the importance of a deeper understanding of the neurodegenerative aspects of STXBP1-E. An in vitro study proposed an interesting new role of STXBP1 as a molecular chaperone for α-Synuclein (αSyn), a key molecule in the pathogenesis of neurodegenerative disorders. However, no studies have shown αSyn pathology in model organisms or patients with STXBP1-E. In this study, we used Drosophila models to examine the effects of STXBP1 haploinsufficiency on αSyn-induced neurotoxicity in vivo. We demonstrated that haploinsufficiency of Ras opposite (Rop), the Drosophila ortholog of STXBP1, exacerbates compound eye degeneration, locomotor dysfunction, and dopaminergic neurodegeneration in αSyn-expressing flies. This phenotypic aggravation was associated with a significant increase in detergent-insoluble αSyn levels in the head. Furthermore, we tested whether trehalose, which has neuroprotective effects in various models of neurodegenerative disorders, mitigates αSyn-induced neurotoxicity exacerbated by Rop haploinsufficiency. In flies expressing αSyn and carrying a heterozygous Rop null variant, trehalose supplementation effectively alleviates neuronal phenotypes, accompanied by a decrease in detergent-insoluble αSyn in the head. In conclusion, this study revealed that Rop haploinsufficiency exacerbates αSyn-induced neurotoxicity by altering the αSyn aggregation propensity. This study not only contributes to understanding the mechanisms of neurodegeneration in STXBP1-E patients, but also provides new insights into the pathogenesis of α-synucleinopathies., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Trehalose-6-phosphate phosphatase (TPP), a key enzyme for trehalose biosynthesis in plants, plays a pivotal role in the growth and development of higher plants, as well as their adaptations to various abiotic stresses. Employing bioinformatics techniques, 45 TPP genes distributed across 17 chromosomes were identified with conserved Trehalose-PPase domains in the peanut genome, aiming to screen those involved in salt tolerance. Collinearity analysis showed that 22 TPP genes from peanut formed homologous gene pairs with 9 TPP genes from Arabidopsis and 31 TPP genes from soybean, respectively. Analysis of cis-acting elements in the promoters revealed the presence of multiple hormone- and abiotic stress-responsive elements in the promoter regions of AhTPPs. Expression pattern analysis showed that members of the TPP gene family in peanut responded significantly to various abiotic stresses, including low temperature, drought, and nitrogen deficiency, and exhibited certain tissue specificity. Salt stress significantly upregulated AhTPPs, with a higher number of responsive genes observed at the seedling stage compared to the podding stage. The intuitive physiological effect was reflected in the significantly higher accumulation of trehalose content in the leaves of plants under salt stress compared to the control. These findings indicate that the TPP gene family plays a crucial role in peanut's response to abiotic stresses, laying the foundation for further functional studies and utilization of these genes., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Zhang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

α,α-trehalose is a well-known sugar that plays a key role in establishing tolerance to environmental stresses in many organisms, except unicellular eukaryotes. However, almost nothing is known about α,β-trehalose, including their synthesis, function, and even presence in living organisms. In this study, we identified α,β-trehalose in the resting cyst, a dormancy cell form characterized by extreme tolerance to environmental stresses, of the ciliated protist Colpoda cucullus, using high-performance liquid chromatography (HPLC), and a proton nuclear magnetic resonance ( 1 H NMR). Gene expression analysis revealed that the expression of trehalose-6-phosphate synthase (TPS), glycosyltransferase (GT), alpha-amylase (AMY), and trehalose transporter 1 (TRET1), were up-regulated in encystment, while the expression of α-glucosidase 2 (AG2) and trehalase (TREH) was up-regulated in excystment. These results suggest that α,β-trehalose is synthesized during encystment process, while and contributes to extreme tolerances to environmental stressors, stored carbohydrates, and energy reserve during resting cyst and/or during excystment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Pterygium is a frequent eye surface condition that is characterized by a high rate of proliferation, fibrovascular development, cellular migration, corneal infiltration, and angiogenesis. We investigated that ex vivo primary pterygium and conjunctival cell cultures were generated to analyze the effect of trehalose on cellular proliferation. After trehalose treatment, we performed microarray analysis to evaluate changes in the mRNA profile. We analyzed gene ontology (GO) and KEGG pathways to identify hub genes that changed expression levels after treatment and were associated with pterygium development. We selected three genes to verify their expression levels using qRT-PCR. The study also evaluated the impact of trehalose treatment on cell migration through a wound-healing assay. Our results suggested that pterygium cell proliferation was inhibited in a dose-dependent manner by trehalose. 2354 DEG were identified in pterygium and conjunctiva cells treated with trehalose compared to untreated groups. Functional enrichment analysis showed that differentially expressed mRNAs are involved in proliferation, vasculature development, and cell migration. We identified ten hub genes including upregulated (RANBP3L, SLC5A3, RERG, ANKRD1, DHCR7, RAB27B, GPRC5B, MSMO1, ASPN, DRAM1) and downregulated (TNC, PTGS2, GREM2, NPTX1, NR4A1, HMOX1, CXCL12, IL6, MYH2, TXNIP). Microarray analysis and functional investigations suggest that trehalose affects the pathogenesis of pterygium by modifying the expression of genes involved in crucial pathways related to cell function., (© 2024 The Author(s). Chemical Biology & Drug Design published by John Wiley & Sons Ltd.)

Phosphorus (P)-hyperaccumulators for phytoextraction from P-polluted areas generally show rapid growth and accumulate large amounts of P without any toxicity symptom, which depends on a range of physiological processes and gene expression patterns that have never been explored. We investigated growth, leaf element concentrations, P fractions, photosynthetic traits, and leaf metabolome and transcriptome response in amphibious P-hyperaccumulators, Polygonum hydropiper and P. lapathifolium, to high-P exposure (5 mmol L -1 ), with 0.05 mmol L -1 as the control. Under high-P exposure, both species demonstrated good growth, allocating more P to metabolite P and inorganic P (Pi) accompanied by high potassium and calcium. The expression of a cluster of unigenes associated with photosynthesis was maintained or increased in P. lapathifolium, explaining the increase in net photosynthetic rate and the rapid growth under high-P exposure. Metabolites of trehalose metabolism, including trehalose 6-phosphate and trehalose, were sharply increased in both species by the high-P exposure, in line with the enhanced expression of associated unigenes, indicating that trehalose metabolic pathway was closely related to high-P tolerance. These findings elucidated the physiological and molecular responses involved in the photosynthesis and trehalose metabolism in P-hyperaccumulators to high-P exposure, and provides potential regulatory pathways to improve the P-phytoextraction capability., (© 2024 John Wiley & Sons Ltd.)

Accumulation of misfolded proteins compromises overall cellular health and fitness. The failure to remove misfolded proteins is a critical reason for their unwanted aggregation in dense cellular protein pools. The accumulation of various inclusions serves as a clinical feature for neurodegenerative diseases. Previous findings suggest that different cellular compartments can store these abnormal inclusions. Studies of transgenic mice and cellular models of neurodegenerative diseases indicate that depleted chaperone capacity contributes to the aggregation of damaged or aberrant proteins, which consequently disturb proteostasis and cell viability. However, improving these abnormal proteins' selective elimination is yet to be well understood. Still, molecular strategies that can promote the effective degradation of abnormal proteins without compromising cellular viability are unclear. Here, we reported that the trehalose treatment elevates endogenous proteasome levels and enhances the activities of the proteasome. Trehalose-mediated proteasomal activation elevates the removal of both bona fide misfolded and various neurodegenerative disease-associated proteins. Our current study suggests that trehalose may retain a proteasome activation potential, which seems helpful in the solubilization of different mutant misfolded proteins, improving cell viability. These results reveal a possible molecular approach to reduce the overload of intracellular misfolded proteins, and such cytoprotective functions may play a critical role against protein conformational diseases., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Trehalose metabolism is related to the sclerotial development of Rhizoctonia solani AG-1 IA, the causal agent of rice sheath blight (RSB). Here, we further elucidated the functions of three genes Rstre , Rstps1 and Rstpp that encode three key enzymes trehalase (TRE), alpha, alpha-trehalose- phosphate synthase (TPS1) and trehalose 6-phosphate phosphatase (TPP) in the sclerotial development of R. solani AG-1 IA. Due to the lack of a stable genetic transformation system for R. solani , the heterologous expression of these three genes in Pichia pastoris GS115 was performed. The results showed that reactive oxygen species (ROS) contents and enzyme activities in R. solani decreased significantly in the treatments of the fermentation broths of Rstps1 and Rstpp transformants, and that in the treatment of the fermentation broth of Rstre transformant visibly increased. Furthermore, the fermentation broths of the transformants of all the three genes were added to potato dextrose agar (PDA) medium for the cultivation of R. solani , as a result, the dry weight of sclerotia in each PDA plate containing the fermentation broths of Rstps1 and Rstpp transformants significantly increased compared with the control, and that of Rstre transformant obviously decreased. Finally, 178 proteins were found to interact with RSTPS1, and 16 of them were associated with ROS. Taken together, the findings suggest that all these three genes related to trehalose metabolism play important roles in the sclerotial development of R. solani AG-1 IA, and can be used as new targets for the development of novel high-efficiency fungicides for the controlling of RSB. [ABSTRACT FROM AUTHOR]

RNAi was used to downregulate the expression of insulin-like peptides (ILP2), with air-modulation, and high-concentration CO2 stress, in the larvae of Tribolium castaneum. We assessed the changes in carbohydrate-related content, trehalase activity, and the expression levels of trehalose pathway genes. And pupation, adult emergence, pupation rate, and mortality were assessed. There was a significant change in the expression of ILPs in T. castaneum , at a certain concentration of CO2. ILP2 RNAi did not alter the trehalose content significantly, however, the glycogen and glucose content increased significantly. High-concentration CO2 stress altered the trehalose content and reduced the glycogen and glucose content. The expression levels of TPS and TRE2 were up-regulated by hypoxia/hypercapnia and dsILP2 combination, with the increase of CO2 concentration, other trehalase genes begin to respond successively. ILP2 knockout raised the mortality and reduced the pupation rate and eclosion rate in CO2. Understanding the insulin pathway responses to hypoxic stress induced by a high concentration of CO2 would further elucidate the mechanisms underlying trehalose metabolism in insects. [ABSTRACT FROM AUTHOR]

Brown planthopper (Nilaparvata lugens) is one of the important pests that damage rice. Trehalose‐6‐phosphate synthase (TPS) is a key enzyme responsible for catalysing the biosynthesis of trehalose, which is the energy substance of insects. In this study, combined with the reported N. lugens TPS1, TPS2 and newly discovered TPS3, we studied the regulation of TPS in chitin metabolism by RNA interference. Firstly, we found that the relative expression levels of TRE1‐1, TRE1‐2 and TRE2 increased significantly after 48 h of dsTPS3 injection, and the activity of TRE1 enhanced significantly. Secondly, abnormal and lethal phenotypes were observed after dsTPS3 and dsTPSs injection. The relative expression levels of PGM2, G6PI2, Cht1‐4, Cht6‐10 and IDGF decreased significantly after 48 h of dsTPS3 injection. At 72 h after injection of dsTPS3, the relative expression levels of CHS1, Cht2, Cht4, Cht7 and Cht8 reduced significantly, but the expression levels of G6PI1, Cht5 and ENGase increased significantly. The relative expression levels of GFAT, UAP, PGM2, G6PI2, CHS1, CHS1a, CHS1b, Cht2, Cht4, Cht8, Cht9 and Cht10 decreased significantly after 48 h of dsTPSs injection. However, at 72 h after the injection of dsTPSs, the expression levels of GNPNA, UAP, PGM1, G6PI1, HK, CHS1, CHS1a, CHS1b, Cht3, Cht5, Cht7 and ENGase increased significantly. Finally, the chitin content decreased in dsTPS1, dsTPS2 and dsTPSs treatments. In conclusion, the inhibition of TPS expression affected the metabolism of trehalose and chitin in N. lugens. The related research results provide a theoretical basis for pest control. [ABSTRACT FROM AUTHOR]

RNAi was used to downregulate the expression of insulin-like peptides (ILP2), with air-modulation, and high-concentration CO2 stress, in the larvae of Tribolium castaneum. We assessed the changes in carbohydrate-related content, trehalase activity, and the expression levels of trehalose pathway genes. And pupation, adult emergence, pupation rate, and mortality were assessed. There was a significant change in the expression of ILPs in T. castaneum, at a certain concentration of CO2. ILP2 RNAi did not alter the trehalose content significantly, however, the glycogen and glucose content increased significantly. High-concentration CO2 stress altered the trehalose content and reduced the glycogen and glucose content. The expression levels of TPS and TRE2 were up-regulated by hypoxia/hypercapnia and dsILP2 combination, with the increase of CO2 concentration, other trehalase genes begin to respond successively. ILP2 knockout raised the mortality and reduced the pupation rate and eclosion rate in CO2. Understanding the insulin pathway responses to hypoxic stress induced by a high concentration of CO2 would further elucidate the mechanisms underlying trehalose metabolism in insects.

Trehalose plays a critical role in plant response to salinity but the involved regulatory mechanisms remain obscure. Here, this study explored the mechanism of exogenous trehalose-induced salt tolerance in tomato plants by the hydroponic test method. Our results indicated that 10 mM trehalose displayed remarkable plant biomass by improving growth physiology, which were supported by the results of chlorophyll fluorescence and rapid light–response curve. In the salinity environment, trehalose + NaCl treatment could greatly inhibit the decrease of malondialdehyde level, and it increases the contents of other osmotic substances, carbohydrates, K+, and K+/Na+ ratio. Meanwhile, trehalose still had similar effects after recovery from salt stress. Furthermore, trehalose pretreatment promoted trehalose metabolism; significantly increased the enzymatic activity of the trehalose metabolic pathway, including trehalose-6-phosphate synthase (TPS), trehalose-6-phosphate phosphatase (TPP), and trehalase (TRE); and upregulated the expression of SlTPS1 , SlTPS5 , SlTPS7 , SlTPPJ , SlTPPH , and SlTRE under saline conditions. However, the transcriptional levels of SlTPS1 , SlTPS5 , and SlTPS7 genes and the activity of TPS enzyme were reversed after recovery. In addition, we found that hydrogen peroxide (H2O2) and superoxide anion (O2−) were accumulated in tomato leaves because of salt stress, but these parameters were all recovered by foliar-applied trehalose, and its visualization degree was correspondingly reduced. Antioxidant enzyme activities (SOD, POD, and CAT) and related gene expression (SlCu/Zn-SOD , SlFe-SOD , SlMn-SOD , SlPOD , and SlCAT) in salt-stressed tomato leaves were also elevated by trehalose to counteract salt stress. Collectively, exogenous trehalose appeared to be the effective treatment in counteracting the negative effects of salt stress. [ABSTRACT FROM AUTHOR]

Cold stress (CS) severely affects several physiological, biochemical, and molecular mechanisms and limits the growth and production of rapeseed (Brassica napus L.). Trehalose (Tre) acts as a growth modulator, which is extensively used to improve the tolerance to multiple plant stresses. Further, Tre also serves as an external force in inducing plant signaling molecules, regulating the expression of stress-responsive genes, and enhancing the CS tolerance in plants. Nevertheless, the importance of exogenous Tre in improving the CS tolerance in rapeseed is still unclear. Therefore, the current study was designed to get mechanistic insights into Tre-mediated CS tolerance in rapeseed seedlings. To explore the Tre role, we designed four treatments [control (CK), CK + 20 mM L–1 Tre, Cold, and Cold + 20 mM L–1 Tre] and three CS conditions (4, 0, and −4°C). The results showed that Tre treatments significantly mitigated the adverse effects of CS on the seedlings and increased the survival rate of Tre-treated seedlings under CS conditions. The exogenous Tre dramatically increased the contents of osmoprotectants, including the soluble sugar (SS), soluble protein (SP), and proline (Pro), and the activities of antioxidant enzymes, such as catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and ascorbate peroxidase (APX) were also increased under CS conditions. Additionally, Tre decreased the malondialdehyde (MDA) contents to protect the rapeseed seedlings. Moreover, Tre also remarkably augmented the expression levels of antioxidant genes (CAT12, POD34 , and FSD7), CS-responsive marker genes (CBF1, CBF2, CBF4, COR6.6, COR15, COR25, COL1 , and KIN1), and Tre-biosynthesis genes (TPS4, TPS8 , and TPS9). Briefly, exogenous Tre not only regulates the antioxidant and osmotic balance, but it also significantly participates in Tre metabolism and signaling network to improve the CS tolerance in rapeseed. Thus, Tre-induced supervisory connections between physiological or/and biochemical attributes provide information to dissect the mechanisms of Tre-mediated CS tolerance. [ABSTRACT FROM AUTHOR]

Background: Metabolism including anabolism and catabolism is a prerequisite phenomenon for all living organisms. Anabolism refers to the synthesis of the entire compound needed by a species. Catabolism refers to the breakdown of molecules to obtain energy. Many metabolic pathways are undisclosed and many organism-specific enzymes involved in metabolism are misplaced. When predicting a specific metabolic pathway of a microorganism, the first and foremost steps is to explore available online databases. Among many online databases, KEGG and MetaCyc pathway databases were used to deduce trehalose metabolic network for bacteria Variovorax sp. PAMC28711. Trehalose, a disaccharide, is used by the microorganism as an alternative carbon source. Results: While using KEGG and MetaCyc databases, we found that the KEGG pathway database had one missing enzyme (maltooligosyl-trehalose synthase, EC 5.4.99.15). The MetaCyc pathway database also had some enzymes. However, when we used RAST to annotate the entire genome of Variovorax sp. PAMC28711, we found that all enzymes that were missing in KEGG and MetaCyc databases were involved in the trehalose metabolic pathway. Conclusions: Findings of this study shed light on bioinformatics tools and raise awareness among researchers about the importance of conducting detailed investigation before proceeding with any further work. While such comparison for databases such as KEGG and MetaCyc has been done before, it has never been done with a specific microbial pathway. Such studies are useful for future improvement of bioinformatics tools to reduce limitations. [ABSTRACT FROM AUTHOR]

Cold stress (CS) severely affects several physiological, biochemical, and molecular mechanisms and limits the growth and production of rapeseed (Brassica napus L.). Trehalose (Tre) acts as a growth modulator, which is extensively used to improve the tolerance to multiple plant stresses. Further, Tre also serves as an external force in inducing plant signaling molecules, regulating the expression of stress-responsive genes, and enhancing the CS tolerance in plants. Nevertheless, the importance of exogenous Tre in improving the CS tolerance in rapeseed is still unclear. Therefore, the current study was designed to get mechanistic insights into Tre-mediated CS tolerance in rapeseed seedlings. To explore the Tre role, we designed four treatments [control (CK), CK + 20 mM L–1 Tre, Cold, and Cold + 20 mM L–1 Tre] and three CS conditions (4, 0, and −4°C). The results showed that Tre treatments significantly mitigated the adverse effects of CS on the seedlings and increased the survival rate of Tre-treated seedlings under CS conditions. The exogenous Tre dramatically increased the contents of osmoprotectants, including the soluble sugar (SS), soluble protein (SP), and proline (Pro), and the activities of antioxidant enzymes, such as catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and ascorbate peroxidase (APX) were also increased under CS conditions. Additionally, Tre decreased the malondialdehyde (MDA) contents to protect the rapeseed seedlings. Moreover, Tre also remarkably augmented the expression levels of antioxidant genes (CAT12, POD34, and FSD7), CS-responsive marker genes (CBF1, CBF2, CBF4, COR6.6, COR15, COR25, COL1, and KIN1), and Tre-biosynthesis genes (TPS4, TPS8, and TPS9). Briefly, exogenous Tre not only regulates the antioxidant and osmotic balance, but it also significantly participates in Tre metabolism and signaling network to improve the CS tolerance in rapeseed. Thus, Tre-induced supervisory connections between physiological or/and biochemical attributes provide information to dissect the mechanisms of Tre-mediated CS tolerance.

Trehalose plays a critical role in plant response to salinity but the involved regulatory mechanisms remain obscure. Here, this study explored the mechanism of exogenous trehalose-induced salt tolerance in tomato plants by the hydroponic test method. Our results indicated that 10 mM trehalose displayed remarkable plant biomass by improving growth physiology, which were supported by the results of chlorophyll fluorescence and rapid light–response curve. In the salinity environment, trehalose + NaCl treatment could greatly inhibit the decrease of malondialdehyde level, and it increases the contents of other osmotic substances, carbohydrates, K+, and K+/Na+ ratio. Meanwhile, trehalose still had similar effects after recovery from salt stress. Furthermore, trehalose pretreatment promoted trehalose metabolism; significantly increased the enzymatic activity of the trehalose metabolic pathway, including trehalose-6-phosphate synthase (TPS), trehalose-6-phosphate phosphatase (TPP), and trehalase (TRE); and upregulated the expression of SlTPS1, SlTPS5, SlTPS7, SlTPPJ, SlTPPH, and SlTRE under saline conditions. However, the transcriptional levels of SlTPS1, SlTPS5, and SlTPS7 genes and the activity of TPS enzyme were reversed after recovery. In addition, we found that hydrogen peroxide (H2O2) and superoxide anion (O2−) were accumulated in tomato leaves because of salt stress, but these parameters were all recovered by foliar-applied trehalose, and its visualization degree was correspondingly reduced. Antioxidant enzyme activities (SOD, POD, and CAT) and related gene expression (SlCu/Zn-SOD, SlFe-SOD, SlMn-SOD, SlPOD, and SlCAT) in salt-stressed tomato leaves were also elevated by trehalose to counteract salt stress. Collectively, exogenous trehalose appeared to be the effective treatment in counteracting the negative effects of salt stress.

The high temperature induces conformational changes in β-glucosidase, making it inactive and limiting its application field. In this paper, the effect of trehalose on the thermostability of β-glucosidase from low-moisture Hevea brasiliensis seeds was investigated. The results showed that the residual enzyme activities of β-glucosidase supplemented with trehalose after high-temperature treatment were significantly higher than that of the control group. The improvement of thermostability could be explained by low-field nuclear magnetic resonance (LF-NMR) and molecular dynamics (MD) simulations at the molecular level. Moreover, adding trehalose increased the water activity and water content of β-glucosidase, leading to a more stable conformation. Trehalose replaced some water and formed a stable network of hydrogen bonds with protein and surrounding water. The glass formed by trehalose also reduced molecular movement, thus providing good protection for enzymes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Tuberculosis remains a large global disease burden for which treatment regimens are protracted and monitoring of disease activity difficult. Existing detection methods rely almost exclusively on bacterial culture from sputum which limits sampling to organisms on the pulmonary surface. Advances in monitoring tuberculous lesions have utilized the common glucoside [ 18 F]FDG, yet lack specificity to the causative pathogen Mycobacterium tuberculosis (Mtb) and so do not directly correlate with pathogen viability. Here we show that a close mimic that is also positron-emitting of the non-mammalian Mtb disaccharide trehalose - 2-[ 18 F]fluoro-2-deoxytrehalose ([ 18 F]FDT) - is a mechanism-based reporter of Mycobacteria-selective enzyme activity in vivo. Use of [ 18 F]FDT in the imaging of Mtb in diverse models of disease, including non-human primates, successfully co-opts Mtb-mediated processing of trehalose to allow the specific imaging of TB-associated lesions and to monitor the effects of treatment. A pyrogen-free, direct enzyme-catalyzed process for its radiochemical synthesis allows the ready production of [ 18 F]FDT from the most globally-abundant organic 18 F-containing molecule, [ 18 F]FDG. The full, pre-clinical validation of both production method and [ 18 F]FDT now creates a new, bacterium-selective candidate for clinical evaluation. We anticipate that this distributable technology to generate clinical-grade [ 18 F]FDT directly from the widely-available clinical reagent [ 18 F]FDG, without need for either custom-made radioisotope generation or specialist chemical methods and/or facilities, could now usher in global, democratized access to a TB-specific PET tracer., (© 2024. The Author(s).)

The cytoplasm is a complex, crowded environment that influences myriad cellular processes including protein folding and metabolic reactions. Recent studies have suggested that changes in the biophysical properties of the cytoplasm play a key role in cellular homeostasis and adaptation. However, it still remains unclear how cells control their cytoplasmic properties in response to environmental cues. Here, we used fission yeast spores as a model system of dormant cells to elucidate the mechanisms underlying regulation of the cytoplasmic properties. By tracking fluorescent tracer particles, we found that particle mobility decreased in spores compared to vegetative cells and rapidly increased at the onset of dormancy breaking upon glucose addition. This cytoplasmic fluidization depended on glucose-sensing via the cyclic adenosine monophosphate-protein kinase A pathway. PKA activation led to trehalose degradation through trehalase Ntp1, thereby increasing particle mobility as the amount of trehalose decreased. In contrast, the rapid cytoplasmic fluidization did not require de novo protein synthesis, cytoskeletal dynamics, or cell volume increase. Furthermore, the measurement of diffusion coefficients with tracer particles of different sizes suggests that the spore cytoplasm impedes the movement of larger protein complexes (40 to 150 nm) such as ribosomes, while allowing free diffusion of smaller molecules (~3 nm) such as second messengers and signaling proteins. Our experiments have thus uncovered a series of signaling events that enable cells to quickly fluidize the cytoplasm at the onset of dormancy breaking., Competing Interests: Competing interests statement:The authors declare no competing interest.

In Escherichia coli , the disaccharide trehalose can be metabolized as a carbon source or be accumulated as an osmoprotectant under osmotic stress. In hypertonic environments, E. coli accumulates trehalose in the cell by synthesis from glucose mediated by the cytosolic enzymes OtsA and OtsB. Trehalose in the periplasm can be hydrolyzed into glucose by the periplasmic trehalase TreA. We have previously shown that a treA mutant of extraintestinal E. coli strain BEN2908 displayed increased resistance to osmotic stress by 0.6 M urea, and reduced production of type 1 fimbriae, reduced invasion of avian fibroblasts, and decreased bladder colonization in a murine model of urinary tract infection. Since loss of TreA likely results in higher periplasmic trehalose concentrations, we wondered if deletion of otsA and otsB genes, which would lead to decreased internal trehalose concentrations, would reduce resistance to stress by 0.6 M urea and promote type 1 fimbriae production. The BEN2908Δ otsBA mutant was sensitive to osmotic stress by urea, but displayed an even more pronounced reduction in production of type 1 fimbriae, with the consequent reduction in adhesion/invasion of avian fibroblasts and reduced bladder colonization in the murine urinary tract. The BEN2908Δ treAotsBA mutant also showed a reduction in production of type 1 fimbriae, but in contrast to the Δ otsBA mutant, resisted better than the wild type in the presence of urea. We hypothesize that, in BEN2908, resistance to stress by urea would depend on the levels of periplasmic trehalose, but type 1 fimbriae production would be influenced by the levels of cytosolic trehalose., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Klemberg, Pavanelo, Houle, Dhakal, Pokharel, Iahnig-Jacques, Dozois and Horn.)