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Summary: The 'assimilates inhibition hypothesis' posits that accumulation of nonstructural carbohydrates (NSCs) in leaves reduces leaf net photosynthetic rate, thus internally regulating photosynthesis. Experimental work provides equivocal support mostly under controlled conditions without identifying a particular NSC as involved in the regulation.We combined 3‐yr in situ leaf gas exchange observations (natural dynamics) in the upper crown of mature Betula pendula simultaneously with measurements of concentrations of sucrose, hexoses (glucose and fructose), and starch, and similar measurements during several one‐day shoot girdling (perturbation dynamics). Leaf water potential and water and nitrogen content were measured to account for their possible contribution to photosynthesis regulation.Leaf photosynthetic capacity (A/Ci) was temporally negatively correlated with NSC accumulation under both natural and perturbation states. For developed leaves, leaf hexose concentration explained A/Ci variation better than environmental variables (temperature history and daylength); the opposite was observed for developing leaves.The weaker correlations between NSCs and A/Ci in developing leaves may reflect their strong internal sink strength for carbohydrates. By contrast, the strong decline in photosynthetic capacity with NSCs accumulation in mature leaves, observed most clearly with hexose, and even more tightly with its constituents, provides support for the role of assimilates in regulating photosynthesis under natural conditions. [ABSTRACT FROM AUTHOR]

Abstract Most of the carbon found in fruits at harvest is imported by the phloem. Imported carbon provide the material needed for the accumulation of sugars, organic acids, secondary compounds, in addition to the material needed for the synthesis of cell walls. The accumulation of sugars during fruit development influences not only sweetness but also various parameters controlling fruit composition (fruit “quality”). The accumulation of organic acids and sugar in grape berry flesh cells is a key process for berry development and ripening. The present review presents an update of the research on grape berry development, anatomical structure, sugar and acid metabolism, sugar transporters, and regulatory factors.

Most of the carbon found in fruits at harvest is imported by the phloem. Imported carbon provide the material needed for the accumulation of sugars, organic acids, secondary compounds, in addition to the material needed for the synthesis of cell walls. The accumulation of sugars during fruit development influences not only sweetness but also various parameters controlling fruit composition (fruit "quality"). The accumulation of organic acids and sugar in grape berry flesh cells is a key process for berry development and ripening. The present review presents an update of the research on grape berry development, anatomical structure, sugar and acid metabolism, sugar transporters, and regulatory factors. [ABSTRACT FROM AUTHOR]

Hydrogen produced from lignocellulosic biomass via dark fermentation is a promising alternative to fossil fuels. This study assessed fermentative H 2 production from single sugars and sugar mixtures mimicking real lignocellulose hydrolysates during a continuous process. The highest hydrogen production rate (HPR) was obtained with pentose sugars, reaching 8.80 and 8.09 L/L-d for arabinose and xylose, respectively. Glucose showed the lowest HPR (6.19 L/L-d), while in the case of sugar mixtures (glucose, cellobiose, xylose, arabinose), HPR was approximately 7.3 L/L-d and was lower than expected from calculations. Thus, cofermentation reduced the H 2 production potential. It was shown that pentose sugars are preferred for hydrogen production, but their utilization is limited by the presence of glucose, which is utilized preferentially in sugar mixtures. Xylose, arabinose and sugar mixtures showed similar H 2 yields (approximately 0.29 mol H 2 /mol C), so the efficiency of substrate conversion into H 2 was comparable for these substrates. The microbial community distribution showed that the Clostridium genus was dominant regardless of the substrate, with Clostridium beijerinckii and Clostridium guangxiense being the main bacterial species. Different substrates did not significantly affect the type of microorganisms present in the microbiome and changed only their relative abundance. [Display omitted] • Long-term continuous fermentative H 2 production from single sugars and their mixtures. • The highest HPR obtained for arabinose (8.80 L/L-d) with 96% substrate utilization. • Sugar mixtures exhibited lower HPRs due to the low consumption of arabinose. • Pentoses are preferred for H 2 production, but their utilization is limited by glucose. • The lowest substrate consumption for glucose resulted in the lowest HPR. [ABSTRACT FROM AUTHOR]

Objective:Sialic acid, hexoses, hexosamines and fucose are components of glycoprotein, glycolipid and/or ganglioside. These glycoconjugates are essential components of cellular membrane and receptors, which are required for normal cellular activities. The levels of these aforementioned glycans are likely to be obstructed under biological conditions (such as oxidative stress) that leads to cellular and tissue damage. Despite the efficacy of valproate as a broad-spectrum antiepileptic drug, it administration is linked to oxidative stress and multiple organ damage. Moringa oleifera leaves have been proven to be bioactive food with diverse biochemical benefits, that include antioxidant, wound healing and tissue protective effects.Methods:In this study, female Sprague-Dawley rats were grouped into four. Group 1: control group given physiological saline; Group 2: animals given only 70% ethanol Moringa leaves extract (0.3 g/kg b.w./day); Group 3: animals that received only sodium valproate (0.5 g/kg b.w./day); Group 4: animals given similar dose of sodium valproate + Moringa extract. The treatments were administered orally for 15 days, and the animals were then fasted overnight and sacrificed. Stomach tissues collected were homogenized in ice-cold normal saline, using a glass homogenizer to make up 10% w/v tissue homogenate.Results:Analysis revealed that valproate administration resulted in elevated levels of sialic acid, hexoses, hexosamine, and fucose in the stomach tissue homogenates. Conversely, the administration of Moringa extract mitigated the adverse effect of valproate on glycan levels.Conclusion:Thus, Moringa leave extract can be a good candidate for attenuating valproate-induced toxicity on stomach tissue.

Simple Summary: Glucose is the preferred carbon source for most cells. Yeast Snf1 (AMPK in mammals) is the main regulator of the response to low glucose availability. In the last years, much progress has been made in understanding the regulation of Snf1. We summarize three different mechanisms that control Snf1 activity: (1) phosphorylation and dephosphorylation of a critical threonine residue; (2) post-translational modification by the addition of a SUMO tag; (3) protonation and de-protonation of a polyhistidine tract. These mechanisms act independently of each other, allowing a flexible response to the availability of carbon sources. Snf1, the fungal homologue of mammalian AMP-dependent kinase (AMPK), is a key protein kinase coordinating the response of cells to a shortage of glucose. In fungi, the response is to activate respiratory gene expression and metabolism. The major regulation of Snf1 activity has been extensively investigated: In the absence of glucose, it becomes activated by phosphorylation of its threonine at position 210. This modification can be erased by phosphatases when glucose is restored. In the past decade, two additional independent mechanisms of Snf1 regulation have been elucidated. In response to glucose (or, surprisingly, also to DNA damage), Snf1 is SUMOylated by Mms21 at lysine 549. This inactivates Snf1 and leads to Snf1 degradation. More recently, glucose-induced proton export has been found to result in Snf1 inhibition via a polyhistidine tract (13 consecutive histidine residues) at the N-terminus of the Snf1 protein. Interestingly, the polyhistidine tract plays also a central role in the response to iron scarcity. This review will present some of the glucose-sensing mechanisms of S. cerevisiae, how they interact, and how their interplay results in Snf1 inhibition by three different, and independent, mechanisms. [ABSTRACT FROM AUTHOR]

Objective: Sialic acid, hexoses, hexosamines and fucose are components of glycoprotein, glycolipid and/or ganglioside. These glycoconjugates are essential components of cellular membrane and receptors, which are required for normal cellular activities. The levels of these aforementioned glycans are likely to be obstructed under biological conditions (such as oxidative stress) that leads to cellular and tissue damage. Despite the efficacy of valproate as a broad-spectrum antiepileptic drug, it administration is linked to oxidative stress and multiple organ damage. Moringa oleifera leaves have been proven to be bioactive food with diverse biochemical benefits, that include antioxidant, wound healing and tissue protective effects. Methods: In this study, female Sprague-Dawley rats were grouped into four. Group 1: control group given physiological saline; Group 2: animals given only 70% ethanol Moringa leaves extract (0.3 g/kg b.w./day); Group 3: animals that received only sodium valproate (0.5 g/kg b. w./day); Group 4: animals given similar dose of sodium valproate + Moringa extract. The treatments were administered orally for 15 days, and the animals were then fasted overnight and sacrificed. Stomach tissues collected were homogenized in ice-cold normal saline, using a glass homogenizer to make up 10% w/v tissue homogenate. Results: Analysis revealed that valproate administration resulted in elevated levels of sialic acid, hexoses, hexosamine, and fucose in the stomach tissue homogenates. Conversely, the administration of Moringa extract mitigated the adverse effect of valproate on glycan levels. Conclusion: Thus, Moringa leave extract can be a good candidate for attenuating valproate-induced toxicity on stomach tissue. [ABSTRACT FROM AUTHOR]

Abstract Background Sugar content is an important indicator of fruit quality. Except for a few wild tomato species that accumulate sucrose in the fruits, most cultivated tomato species accumulate hexose. Although several studies have focused on wild sucrose-accumulating tomato, the sucrose accumulation mechanism is still unclear. Results Here, two homozygous inbred cherry tomato lines (‘TB0023’ and ‘TB0278’, which accumulated sucrose and hexose, respectively) were selected to analyze the sugar accumulation mechanism. Carbohydrate analysis, cytological observation, gene expression and enzyme activity analysis and proteomics methods were used in this study. The results indicated that glucose and fructose were absolutely dominant in the soluble sugar content of hexose-accumulating cherry tomato fruit, while sucrose and a certain proportion of hexose were the main forms of soluble sugar in sucrose-accumulating cherry tomato fruit. The phloem unloading pathway of the hexose-accumulating cherry tomato fruit switched from symplastic to apoplastic during fruit development, and the sucrose-accumulating cherry tomato probably had a mixed unloading pathway involving the symplastic and apoplastic. High activity of acid invertase (AI), sucrose phosphate synthase (SPS), sucrose synthase (SS) and sugar transporters LeSUT1, SlSWEET2a and SlSWEET12c were important factors for hexose accumulation in the hexose-accumulating cherry tomato fruit, while LeSUT2, SPS, SS, SlSWEET1b, SlSWEET5b, SlSWEET11b, SlSWEET7a, SlSWEET14 were responsible for solute sugar accumulation in the sucrose-accumulating cherry tomato. Conclusions This study provides detailed evidence for elucidation of the tomato sugar accumulation mechanism from the perspective of cell structure, physiology and molecular biology, providing a theoretical basis for the improvement of tomato quality and aiding the utilization of tomato genetic resources.

As a leaf vegetable, Gynura bicolor DC (G. bicolor) experiences a rapid deterioration after harvest including insufficient supply of sugar and destruction of cell membranes. In this research, four treatments were experimented on G. bicolor including the control (CK), 12% (g/g) sucrose (ST), 10 μL L−1 1-MCP (MT), and the combination of sucrose and 1-MCP (SMT). The results showed that three treated groups reduced respiratory rate, inhibited hexose consumption and promoted the decrease of starch and sucrose, which was converted into hexose including glucose and fructose to maintain cell membrane integrity. Meanwhile, the activities of AI, NI, SS-C, amylase, and corresponding gene expression levels were significantly up-regulated in three treated groups at 1 d, among which AI played a crucial role in regulating the accumulation of hexose. Furthermore, ST exerted a pronounced effect on hexose accumulation at the beginning while MT reduced hexose consumption through lowered respiratory metabolism during storage. Notably, SMT exhibited an optimum preservation effect on inhibited respiratory metabolism, maintaining cell membrane integrity, enhancing the retention of hexose, indicating that a synergistic effect of ST and MT were developed during storage. • Sucrose treatment promoted early retention of soluble sugar and hexose accumulation. • 1-MCP treatment kept a long-term effect on sugar scarcity by inhibiting respiration. • Combined treatment increased hexose accumulation optimally. • Enhanced hexose content moderated cell membrane damage. [ABSTRACT FROM AUTHOR]

Background: Sugar content is an important indicator of fruit quality. Except for a few wild tomato species that accumulate sucrose in the fruits, most cultivated tomato species accumulate hexose. Although several studies have focused on wild sucrose-accumulating tomato, the sucrose accumulation mechanism is still unclear. Results: Here, two homozygous inbred cherry tomato lines ('TB0023' and 'TB0278', which accumulated sucrose and hexose, respectively) were selected to analyze the sugar accumulation mechanism. Carbohydrate analysis, cytological observation, gene expression and enzyme activity analysis and proteomics methods were used in this study. The results indicated that glucose and fructose were absolutely dominant in the soluble sugar content of hexose-accumulating cherry tomato fruit, while sucrose and a certain proportion of hexose were the main forms of soluble sugar in sucrose-accumulating cherry tomato fruit. The phloem unloading pathway of the hexose-accumulating cherry tomato fruit switched from symplastic to apoplastic during fruit development, and the sucrose-accumulating cherry tomato probably had a mixed unloading pathway involving the symplastic and apoplastic. High activity of acid invertase (AI), sucrose phosphate synthase (SPS), sucrose synthase (SS) and sugar transporters LeSUT1, SlSWEET2a and SlSWEET12c were important factors for hexose accumulation in the hexose-accumulating cherry tomato fruit, while LeSUT2, SPS, SS, SlSWEET1b, SlSWEET5b, SlSWEET11b, SlSWEET7a, SlSWEET14 were responsible for solute sugar accumulation in the sucrose-accumulating cherry tomato. Conclusions: This study provides detailed evidence for elucidation of the tomato sugar accumulation mechanism from the perspective of cell structure, physiology and molecular biology, providing a theoretical basis for the improvement of tomato quality and aiding the utilization of tomato genetic resources. [ABSTRACT FROM AUTHOR]

A benchmark of sugar produced from simple glycolaldehyde derivative has been achieved at ambient conditions (Science, 2004, 305, 1752), which is the most important step to produce life in nature. However, the mechanism has never been clearly understood. Here, we report a reaction mechanism which includes a two‐step synthesis of sugars by selective aldol reactions based on the density functional theory (DFT) calculations. Results show that the prochirality of attacking orientation of the enamine intermediate and steric effect in proton transfer is the main cause for stereochemical preference. This work provides the theoretical insight of sugar produced in glycolaldehyde procedure and may assist the improvement of catalyst design for this procedure. [ABSTRACT FROM AUTHOR]

• Japanese Azadinium poporum produces AZA2 as dominant toxin and several AZAs. • Twelve new AZAs were discovered from Japanese Azadinium poporum. • New AZAs detected as bi-charged ions were discovered. • AZAs detected as bi-charged ions were sulfated AZAs and some had hexoses. Lipophilic marine biotoxin azaspiracids (AZAs) are produced by dinoflagellates Azadinium and Amphidoma. Recently, several strains of Azadinium poporum were isolated from Japanese coastal waters, and detailed toxin profiles of two strains (mdd421 and HM536) among them were clarified by several detection techniques on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and liquid chromatography-quadrupole time of flight mass spectrometry (LC-QTOFMS). In our present study, AZA analogues in seven strains of A. poporum from Japanese coastal waters (including two previously reported strains) were determined by these detection techniques. The dominant AZA in the seven strains was AZA2 accompanied by small amounts of several known AZAs and twelve new AZA analogues. Eight of the twelve new AZA analogues discovered in our present study were detected as bi-charged ions on the positive mode LC/MS/MS. This is the first report describing AZA analogues detected as bi-charged ions with hexose and sulfate groups in their structures. [ABSTRACT FROM AUTHOR]

Leaf removal (LR) around the cluster zone is a common practice for regulating grape quality. The purpose of this study was to assess the effects of cluster-zone leaf removal, applied at the pea-size stage of berry development, on berry soluble sugar, organic acid and phenolic compound, sugar unloading-related gene expression of Vitis. vinifera L. Syrah. Four different severities of leaf removal were applied: no leaf removal (Control), removing 2 leaves above the cluster (LR1), removing 4 leaves above the cluster (LR2), and removing 6 leaves above the cluster (LR3). The three leaf removal treatments (LR), especially removing 4 leaves (LR2), resulted in significantly higher reducing sugar, soluble sugar (glucose, fructose and sucrose), total anthocyanin and citric acid contents as compared to the control group during ripening for both vintages. At harvest, the LR treatments increased the transcript abundance of most sugar unloading-related genes. In addition , VvHT3, VvHT5, VvSUC11, VvSUC12, VvSS and VvcwINV were positively correlated with both reducing sugar contents and soluble sugar contents. Our results suggest that removing 4 leaves above the cluster is useful for improving the quality of Syrah (Vitis vinifera L.) grapes in cool climate regions with excessive leaves. These findings provide insights into the molecular basis of the relationship between leaf removing and hexose (glucose and fructose) accumulation in the grape berries. • The hexose, total anthocyanin and citric acid contents were increased by leaf removal. • There was no difference in sucrose content. • Leaf removal induced sucrose breakdown to generate more hexose. • Most genes associated with sugar unloading were up-regulated at harvest by leaf removal. [ABSTRACT FROM AUTHOR]

Climate change is known to simultaneously increase berry sugars but decrease anthocyanins, leading to an imbalance between sugars and anthocyanins in grape berries. To restore the balance of sugars and anthocyanins, carbon limitation by leaf removal and exogenous abscisic acid (ABA) were separately or simultaneously applied to Vitis vinifera cv. Cabernet Sauvignon fruit cuttings to decipher their effects on berry quality with metabolite and whole-genome transcriptome analyses. Carbon limitation decreased the hexose concentration and fully blocked the accumulation of anthocyanins. However, exogenous ABA increased the anthocyanin concentration under both carbon limitation and sufficient conditions. Carbon limitation and exogenous ABA induced the profound remodeling of the whole-genome transcriptome and altered the anthocyanin concentration by regulating the transcription levels of genes involved in the anthocyanin biosynthesis pathways as well as in the genes involved in various types of hormone signaling. Moreover, two pertinent candidate genes were identified based on the co-expression network analysis between the berry metabolite and transcriptome results, including a transcriptional factor, ERF2, and a calcineurin B-like protein-interacting protein kinase gene, CIPK25. In summary, simultaneously modifying the carbon supply by leaf removal and spraying exogenous ABA could re-establish the balance between sugars and anthocyanins to improve the qualities of grape berries via whole-genome transcriptome remodeling.

Background: It is widely acknowledged that dietary habits have profound impacts on human health and diseases. As the most important sweeteners and energy sources in human diets, hexoses take part in a broad range of physiopathological processes. In recent years, emerging evidence has uncovered the crucial roles of hexoses, such as glucose, fructose, mannose, and galactose, in controlling the differentiation or function of immune cells., Aim of Review: Herein, we reviewed the latest research progresses in the hexose-mediated modulation of immune responses, provided in-depth analyses of the underlying mechanisms, and discussed the unresolved issues in this field., Key Scientific Concepts of Review: Owing to their immunoregulatory effects, hexoses affect the onset and progression of various types of immune disorders, including inflammatory diseases, autoimmune diseases, and tumor immune evasion. Thus, targeting hexose metabolism is becoming a promising strategy for reversing immune abnormalities in diseases., 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 © 2023. Production and hosting by Elsevier B.V.)

High glucose and fructose intake have been proven to display pro-inflammatory roles during the progression of inflammatory diseases. However, mannose has been shown to be a special type of hexose that has immune regulatory functions. In this review, we trace the discovery process of the regulatory functions of mannose and summarize some past and recent studies showing the therapeutic functions of mannose in inflammatory diseases. We conclude that treatment with mannose can suppress inflammation by inducing regulatory T cells, suppressing effector T cells and inflammatory macrophages, and increasing anti-inflammatory gut microbiome. By summarizing all the important findings, we highlight that mannose treatment is a safe and promising novel strategy to suppress inflammatory diseases, including autoimmune disease and allergic disease. [ABSTRACT FROM AUTHOR]

High glucose and fructose intake have been proven to display pro-inflammatory roles during the progression of inflammatory diseases. However, mannose has been shown to be a special type of hexose that has immune regulatory functions. In this review, we trace the discovery process of the regulatory functions of mannose and summarize some past and recent studies showing the therapeutic functions of mannose in inflammatory diseases. We conclude that treatment with mannose can suppress inflammation by inducing regulatory T cells, suppressing effector T cells and inflammatory macrophages, and increasing anti-inflammatory gut microbiome. By summarizing all the important findings, we highlight that mannose treatment is a safe and promising novel strategy to suppress inflammatory diseases, including autoimmune disease and allergic disease.

Glomalin, one of the glycoproteins generated in the spores and hyphae of arbuscular mycorrhizal (AM) fungi, has multiple functions in plants and soil, while the role of foliar spray of easily extractable glomalin-related soil proteins (EE-GRSP) in citrus fruits is not well defined. Our study aimed to use referenced transcriptome sequencing to uncover the mechanism and the role of exogenous EE-GRSP in two late-ripening varieties of sweet orange (Citrus sinensis) fruits including Navel Lane Late (LW) and Rohde Red Valencia (XC). The 1804 and 1861 differentially expressed genes were identified in fruits of LW and XC, respectively, following foliar spray of EE-GRSP. Photosynthesis ranked second in the Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolism in the LW variety, and carbon fixation in photosynthetic organizations ranked first in KEGG metabolism in the XC variety. The response to foliar spray of EE-GRSP affected the fruit starch and sucrose metabolism of KEGG, with 15 (10 up-regulated and 5 down-regulated) and 13 (2 up-regulated and 11 down-regulated) differentially expressed genes identified in the LW and XC variety, respectively. Cs5g19060 (sucrose phosphate synthase 4) was activated and reduced by EE-GRSP on XC and LW, respectively. Cs1g18220 (β-fructofuranosidase) and Cs2g12180 (glycosyl hydrolase family 9) genes were up-regulated and down-regulated in LW and XC, respectively. These results established the involvement of molecular signaling in response to foliar spray of EE-GRSP activating fruit sugar metabolism is dependent on citrus varieties.

The upregulation of glucose transporter (GLUT) is a typical pathological marker in numerous cancer types and a potential target for anti-cancer drug therapy. We developed a cell membrane-based glucose sensor for real-time monitoring of GLUT transport kinetics. By combining hydrogel layers and liposomes, a planar cell membrane was constructed over the electrode, preventing pore leakage and allowing for highly sensitive and selective measurements. Based on this continuous monitoring technique, we investigated the effect of GLUT1-specific inhibitors such as Cytorelaxation B and BAY-876. We also measured the affinity of different hexoses to GLUT1 using a normalized response time comparison based on the cell membrane sensor. Experimental results were consistent with the molecular docking simulation, indicating that the sensor can be adapted to measure the glucose transport kinetics in different pharmacological conditions. This work demonstrated that cell membrane transport channels could maintain their transmembrane function in-vitro , and it has potential application in evaluating drug-receptor interaction. [Display omitted] • Developed cell membrane biosensor to monitor GLUT1 transport kinetics in real-time. • Investigated the inhabitation effect of GLUT1-specific molecules. • Measured the GLUT1 affinity and transport procedure of different hexoses. [ABSTRACT FROM AUTHOR]

[Display omitted] • The optimum pH for H 2 production from mixed sugars depends on the HRT conditions. • Sugar utilization decreased in the following order: cellobiose > xylose > arabinose. • The pH, in contrast to HRT, had a significant influence on the bacteria composition. • C. guangxiense was the predominant bacteria at pH 5, while C. beijerinckii at pH 6. • The correlation between the B/A ratio and H 2 yield is strictly pH dependent. This study assessed the effect of hydraulic retention time (HRT) ranging from 24 to 3 h on continuous dark-fermentative H 2 production in four bioreactors operated at pH 5.0, 5.5, 6.0 and 6.5. A mixture of cellobiose, xylose and arabinose was used as the substrate. The highest hydrogen production rate between HRTs of 24 and 12 h was observed at pH 6.5, while at HRT below 12 h at pH 6.0. At a HRT of 3 h it reached 11.4 L H 2 /L-d. Thus, the optimum pH for H 2 production depends on the HRT. The highest sugar utilization was obtained at pH 6.0 and 6.5 and decreased in the following order: cellobiose > xylose > arabinose. The pH conditions, in contrast to HRT, were found to have a significant influence on the bacterial composition. Low diversity in bacterial culture dominated by the Clostridium genus allows for stable and high H 2 production performance. [ABSTRACT FROM AUTHOR]

Typical value-added platform chemicals 5-hydroxymethylfurfural (HMF) and levulinic acid (LA) can be obtained from hexoses under microwave hydrothermal (MHT) conditions. This study explored the detailed transformation process regarding the MHT products in acidic seawater obtained using glucose and fructose as raw materials. The facile conversion of fructose compared with glucose was mainly ascribed to their different activation energies (56.721 and 88.594 kJ mol -1 , respectively). The HMF and LA product yields were strongly affected by the MHT temperature and holding time in two types of hexose solution. Undesirable humins were found to inevitably form under each set of reaction conditions. The carbon balance results for reactants and products showed that up to 60% of fructose carbon was converted into value-added chemicals, while 47% of glucose carbon underwent the same conversion in acidic seawater under the optimal MHT conditions. This study provides further knowledge regarding the role of microwave heating combined with acidic seawater in green chemistry and is a useful reference for the biorefinery industry.

Glomalin, one of the glycoproteins generated in the spores and hyphae of arbuscular mycorrhizal (AM) fungi, has multiple functions in plants and soil, while the role of foliar spray of easily extractable glomalin-related soil proteins (EE-GRSP) in citrus fruits is not well defined. Our study aimed to use referenced transcriptome sequencing to uncover the mechanism and the role of exogenous EE-GRSP in two late-ripening varieties of sweet orange (Citrus sinensis) fruits including Navel Lane Late (LW) and Rohde Red Valencia (XC). The 1804 and 1861 differentially expressed genes were identified in fruits of LW and XC, respectively, following foliar spray of EE-GRSP. Photosynthesis ranked second in the Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolism in the LW variety, and carbon fixation in photosynthetic organizations ranked first in KEGG metabolism in the XC variety. The response to foliar spray of EE-GRSP affected the fruit starch and sucrose metabolism of KEGG, with 15 (10 up-regulated and 5 down-regulated) and 13 (2 up-regulated and 11 down-regulated) differentially expressed genes identified in the LW and XC variety, respectively. Cs5g19060 (sucrose phosphate synthase 4) was activated and reduced by EE-GRSP on XC and LW, respectively. Cs1g18220 (β-fructofuranosidase) and Cs2g12180 (glycosyl hydrolase family 9) genes were up-regulated and down-regulated in LW and XC, respectively. These results established the involvement of molecular signaling in response to foliar spray of EE-GRSP activating fruit sugar metabolism is dependent on citrus varieties. [ABSTRACT FROM AUTHOR]

Cucumber (Cucumis sativus L.), an important vegetable plant species, is susceptible to low temperature stress especially during the seedling stage. Vacuolar invertase (VI) plays important roles in plant responses to abiotic stress. However, the molecular and biochemical mechanisms of VI function in cucumber, have not yet been completely understood and VI responses to low temperature stress and it functions in cold tolerance in cucumber seedlings are also in need of exploration. The present study found that hexose accumulation in the roots of cucumber seedlings under low temperature stress is closely related to the observed enhancement of invertase activity. Our genome-wide search for the vacuolar invertase (VI) genes in cucumber identified the candidate VI-encoding gene CsVI1. Expression profiling of CsVI1 showed that it was mainly expressed in the young roots of cucumber seedlings. In addition, transcriptional analysis indicated that CsVI1 expression could respond to low temperature stress. Recombinant CsVI1 proteins purified from Pichia pastoris and Nicotiana benthamiana leaves could hydrolyze sucrose into hexoses. Further, overexpression of CsVI1 in cucumber plants could increase their hexose contents and improve their low temperature tolerance. Lastly, a putative cucumber invertase inhibitor was found could form a complex with CsVI1. In summary, these results confirmed that CsVI1 functions as an acid invertase involved in hexose accumulation and responds to low temperature stress in cucumber seedlings. [ABSTRACT FROM AUTHOR]