Carbohydrate Regulation Research Articles

Hormone and carbohydrate regulation of defense secondary metabolites in a Mediterranean forest during drought

Plants have evolved complex physiological mechanisms to regulate production of defense secondary metabolites (SMs) to cope with environmental stress such as drought. Yet, these mechanisms remain under-studied in mature trees, limiting our ability to understand effects of climate change on tree productivity and survival. We investigated defense SMs and their relations to growth, nonstructural carbohydrates and phytohormones across seasons, in a Mediterranean forest dominated by two tree species with different resistance to drought. Our results showed seasonality of leaf SMs, with a strong accumulation of SMs during cold and dry conditions in winter. The drought-resistant species Phillyrea latifolia had high levels of SMs in both leaves (ca. 10–20%) and stem phloem (4–6%), but experimental drought decreased SMs and soluble sugars in stem phloem in spring and summer. By contrast, the drought-susceptible species Quercus ilex had relatively low and constant levels of SMs, irrespective of drought. We further showed that P. latifolia leaves had generally higher levels of jasmonic acid and lower salicylic acid than Q. ilex leaves, potentially leading to differences in SMs and growth between the two co-occucrring species. Our study suggests that species- and organ-specific dynamics of defense SMs are driven by phytohormones and carbohydrates in mature trees, and that P. latifolia may become less resistant to abiotic and biotic stress due to reduced phloem defense SMs and carbohydrates in a drying climate.

MiR-122 dysregulation is associated with type 2 diabetes mellitus-induced dyslipidemia and hyperglycemia independently of its rs17669 variant

miR-122 is a liver specific micro-RNA that participates in the regulation of carbohydrate and lipid metabolism. The rs17669 variant of miR-122 is positioned at the flanking region of miR-122 and may affect its stability and maturation. Therefore, this study was aimed to investigate the association of the rs17669 polymorphism with the miR-122 circulating level, risk of type 2 diabetes mellitus (T2DM) development, and biochemical parameters in T2DM patients and matched healthy controls. This study involved 295 subjects (controls: n = 145 and T2DM: n = 150). The rs17669 variant genotyping was done by ARMS-PCR. Serum biochemical parameters including lipid profile, small-dense low density lipoprotein (sdLDL) and glucose were measured by colorimetric kits. Insulin and Glycated hemoglobin (HbA1c) were assayed using ELISA and capillary electrophoresis methods, respectively. miR-122 expression was measured by real-time PCR. There was no significant difference between study groups in terms of allele and genotype distribution (P > 0.05). The rs17669 variant did not have any significant association with miR-122 gene expression and biochemical parameters (P > 0.05). miR-122 expression level in T2DM patients was significantly higher than that in control subjects (5.7 ± 2.4 vs. 1.4 ± 0.78) (P < 0.001). Furthermore, miR-122 fold change had a positive and significant correlation with low-density lipoprotein cholesterol (LDL-C), sdLDL, fasting blood sugar (FBS), and insulin resistance (P < 0.05). It can be concluded that the rs17669 variant of miR-122 is not associated with the miR-122 expression and T2DM-associated serum parameters. Furthermore, it can be suggested that miR-122 dysregulation is involved in T2DM development through inducing dyslipidemia, hyperglycemia, and resistance to insulin.

Grafting Causes Physiological Changes and Promotes Adventitious Root Formation in Rejuvenated Soft Shoots of Taxodium hybrid ‘Zhongshanshan’

Taxodium hybrid 'Zhongshanshan' has been widely used as a timber tree in river network areas and coastal regions and is mainly propagated by cuttings. However, when trees age, their capacity to form adventitious roots becomes weaker. We successfully enhanced the rooting ability of shoots in T. hybrid 'Zhongshanshan 302' by their rejuvenation based on grafting. We recorded temporal variation in endogenous auxin, abscisic acid (ABA), gibberellins (GAs), trans-zeatin-riboside (TZR), soluble sugar and H2O2 after root induction. Auxin, soluble sugars and H2O2 levels were higher in rejuvenated shoots than in mature shoots, whereas the opposite was true for ABA and GAs. Notably, indole-3-acetic acid (IAA) and GA3 presented higher contents with more obvious differences in T. hybrid 'Zhongshanshan 302' rejuvenated shoots vs. mature shoots compared with other kinds of auxin and GAs. The evident improvement in the rooting ability of rejuvenated shoots after grafting likely resulted from the differential regulation of plant hormones, carbohydrates and redox signaling. In addition to the physiological basis of improved rooting ability by grafting, this study provided a theoretical basis for the optimization of subsequent propagation techniques in T. hybrid 'Zhongshanshan' and potentially other Taxodium spp.

FEATURES OF CARBOHYDRATE-LIPID METABOLISM IN DOGS WITH DIFFERENT TYPES OF HIGHER NERVOUS ACTIVITY

The relevance of the study is due to the lack of data on the cortical mechanisms of regulation of carbohydrate and lipid metabolism in the body of dogs. In this regard, this article is aimed at revealing the issue of lipid and carbohydrate metabolism in dogs with various types of higher nervous activity under the influence of short-term food deprivation. It is shown that the effect of short-term food deprivation is characterized by changes in metabolism in the body of dogs, which are limited by the state of the nervous system of these animals. In the intact state, the glucose content in the blood of dogs with different types of higher nervous activity does not reliably differ, while the lactate content in the blood of dogs with a weak type of higher nervous activity is higher by 16.2% (P &lt; 0.01), and pyruvate is lower by 6.3% (P &lt; 0.001) from the indicators of dogs with a strong balanced mobile type. Within a day after the beginning of food deprivation, the glucose content in the blood of dogs decreases by 4.6–8.2% depending on the type of nervous activity (P &lt; 0.05–0.01). During the day after the beginning of deprivation, the ratio of lactate to pyruvate in the blood of dogs, depending on the type of higher nervous activity, increases by 19.1–36.0% (Р &lt; 0.01), the content of total cholesterol and triacylglycerols in the blood plasma decreases by 3, 5–12.9% and the ratio of lipids of different densities changes significantly. In particular, in the blood plasma of dogs of a strong balanced mobile type of higher nervous activity, the cholesterol content of high-density lipoproteins decreased during the day by 7.1% (Р &lt; 0.05). Thanks to the conducted research, it was possible to obtain fundamental knowledge of the cortical mechanisms of regulation of carbohydrates and lipids in the body of dogs, which will form the basis of the development of new, modern methods of correction of metabolism, taking into account the type of higher nervous activity. Prospects for further research consist in the development of new methods of correction of metabolism based on the use of nanoaquachelates of biogenic metals, taking into account the individual characteristics of the body of dogs.

Fibroblast Growth Factor 21 Levels and Bone Mineral Density in Metabolically Healthy and Metabolically Unhealthy Obese Children

The harmful or beneficial effect of obesity on bone mineral density (BMD) remains controversial in children and adolescents. Fibroblast growth factor 21 (FGF21) is a metabolic factor that plays a specific role in the regulation of carbohydrate and lipid metabolism. However, the role of FGF21 in bone metabolism appears paradoxical and is complex. To determine whether serum FGF21 level was associated with BMD in obese children and adolescents. The study was conducted with the participation of children and adolescents aged 8-18 years. Ninety-eight obese children were included in the study group and 44 children were included in the control group. BMD, in addition to the routine obesity workup, which includes fasting blood glucose, fasting insulin levels, lipid profile, and liver enzymes; serum FGF21 levels have been analyzed. The mean age of the obese group (n=98) was 13.34±2.24 years and the mean age of controls (n=44) was 13.48±2.87 years. Based on International Diabetes Federation criteria, 15 of 98 (15.3%) patients were metabolically unhealthy. FGF21 levels were 193.54±139.62 mg/dL in the obese group and 158.69±151.81 mg/dL in the control group (p=0.06). There was no difference between the FGF21 and BMD z-score values of girls and boys in the obese and control groups (p>0.05). BMD-z-score was increased in obese children compared to healthy control. Moreover, BMD-z-score tended to be higher when more metabolic risk factors were present. However, there was no significant relationship between FGF21 levels and BMD z-score values in obese children.

New insights into activation and function of the AMPK.

The classical role of AMP-activated protein kinase (AMPK) is as a cellular energy sensor activated by falling energy status, signalled by increases in AMP to ATP and ADP to ATP ratios. Once activated, AMPK acts to restore energy homeostasis by promoting ATP-producing catabolic pathways while inhibiting energy-consuming processes. In this Review, we provide an update on this canonical (AMP/ADP-dependent) activation mechanism, but focus mainly on recently described non-canonical pathways, including those by which AMPK senses the availability of glucose, glycogen or fatty acids and by which it senses damage to lysosomes and nuclear DNA. We also discuss new findings on the regulation of carbohydrate and lipid metabolism, mitochondrial and lysosomal homeostasis, and DNA repair. Finally, we discuss the role of AMPK in cancer, obesity, diabetes, nonalcoholic steatohepatitis (NASH) and other disorders where therapeutic targeting may exert beneficial effects.

Secondary Metabolite Profile and Pharmacological Opportunities of Lettuce Plants following Selenium and Sulfur Enhancement.

Selenium (Se) is an essential trace nutrient for humans and animals owing to its role in redox regulation, thyroid hormone control factors, immunity, inflammatory reactions, brain activities, and carbohydrate regulation. It is also important to support muscle development, as well as for reproductive and cardiovascular well-being. Furthermore, sulfur is known to be a healing element, due to the remarkable function of specialized and secondary S-containing compounds. The scope of the current study was to determine the impact of Se and S enrichment on the secondary metabolite accumulation and antibacterial and NO inhibition activities in green and red leaf lettuce (V1 and V2, respectively). The plants were grown in a hydroponic system supplied with different S concentrations (S0: 0, S1: 1 mM and S2: 1.5 mM K2SO4) via the nutrient solution and foliar-applied varying levels of Se (0, 0.2 and 2.6 µM). Electrospray ionization-quadrupole time-of-flight mass spectrometry (ESI-QTOF/MS) combined with ultra-performance liquid chromatography (UPLC) was used to identify the secondary metabolites in green and red lettuce. The results indicated that extracts of the biofortified lettuce were not cytotoxic to Vero kidney cells at the highest concentration tested of 1 mg/mL. The ESI/MS of the tentatively identified metabolites showed that the response values of 5-O-caffeoylquinic acid, cyanidin 3-O-galactoside, quercetin 3-O-(6''-acetyl-glucoside) and quercetin 3-O-malonylglucoside were induced synergistically under higher Se and S levels in red lettuce plants. The acetone extract of red lettuce had antibacterial activity against Pseudomonas aeruginosa, with a minimum inhibitory concentration (MIC) of 0.156 and 0.625 μg/mL under S2/Se1 and S2/Se2 treatments, respectively. As with antibacterial activity, the acetone extract of green (V1) lettuce treated with adequate (S1) and higher S (S2) under Se-limiting conditions showed the ability to inhibit nitric oxide (NO) release from macrophages. NO production by macrophages was inhibited by 50% at respective concentrations of 106.1 ± 2.4 and 101.0 ± 0.6 μg/mL with no toxic effect on the cells, in response to S1 and S2, respectively, under Se-deficient conditions (Se0). Furthermore, the red cultivar (V2) exhibited the same effect as the green cultivar (V1) regarding NO inhibition, with IC50 = 113.0 ± 4.2 μg/mL, in response to S1/Se2 treatments. Collectively, the promising NO inhibitory effect and antibacterial activity of red lettuce under the above-mentioned conditions might be attributed to the production of flavonoid glycosides and phenylpropanoic acid esters under the same condition. To the best of our knowledge, this is the first report to show the novel approach of the NO inhibitory effect of Se and S enrichment in food crops, as an indicator for the potential of Se and S as natural anti-inflammatory agents.

Identification of Key Genes Related to Dormancy Control in Prunus Species by Meta-Analysis of RNAseq Data.

Bud dormancy is a genotype-dependent mechanism observed in Prunus species in which bud growth is inhibited, and the accumulation of a specific amount of chilling (endodormancy) and heat (ecodormancy) is necessary to resume growth and reach flowering. We analyzed publicly available transcriptome data from fifteen cultivars of four Prunus species (almond, apricot, peach, and sweet cherry) sampled at endo- and ecodormancy points to identify conserved genes and pathways associated with dormancy control in the genus. A total of 13,018 genes were differentially expressed during dormancy transitions, of which 139 and 223 were of interest because their expression profiles correlated with endo- and ecodormancy, respectively, in at least one cultivar of each species. The endodormancy-related genes comprised transcripts mainly overexpressed during chilling accumulation and were associated with abiotic stresses, cell wall modifications, and hormone regulation. The ecodormancy-related genes, upregulated after chilling fulfillment, were primarily involved in the genetic control of carbohydrate regulation, hormone biosynthesis, and pollen development. Additionally, the integrated co-expression network of differentially expressed genes in the four species showed clusters of co-expressed genes correlated to dormancy stages and genes of breeding interest overlapping with quantitative trait loci for bloom time and chilling and heat requirements.

Halophila beccarii extract ameliorate glucose uptake in 3T3-L1 adipocyte cells and improves glucose homeostasis in streptozotocin-induced diabetic rats

The regulation of carbohydrate metabolizing enzymes is an effective way of reducing blood glucose levels and improving glycogen synthesis during the management of type 2 diabetes. The present investigation was conducted to explain the detailed mechanism with which a Seagrass, Halophila beccarii extract (HBE) enhances the glucose uptake in the 3T3-L1 adipocyte cell culture system in invitro. HBE stimulates the glucose uptake by the translocation of glucose transporter 4 (GLUT4) on to plasma cell membrane through induction of insulin receptor substrate 1 (IRS-1)/protein kinase B (Akt) signaling pathways. To assess the effect of HBE on T2DM, we used invivo experimental diabetes rat models induced with streptozotocin (STZ) to perform oral GTT and ITT. Furthermore, we assessed the enzymatic profile of Glycolysis, Pentose phosphate pathway, and gluconeogenesis from liver tissue homogenate. After long-term exposure with HBE, our results confirmed, that HBE improves the glucose uptake in 3T3-L1 cell lines by up-regulation of glucose transporter type 4 (GLUT4) through uptake of glucose by the adipocytes. The resulting data indicated that HBE had a great potentiality in preventing diabetes and maintaining glucose homeostasis through improving glucose uptake. The present data also showed that HBE with its insulin mimetic activity activates glycogen synthesis and enhances glucose utilization by regulating the carbohydrate metabolic enzymes. The similarity between HBE and insulin indicates that the HBE follows the mechanisms same as the insulin signaling pathway to show the antidiabetic activity.

The chromosome-scale genome provides insights into pigmentation in Acer rubrum

Acer rubrum L. is one of the most prevalent ornamental species of the genus Acer, due to its straight and tall stems and beautiful leaf colors. For this study, the Oxford Nanopore platform and Hi-C technology were employed to obtain a chromosome-scale genome for A. rubrum. The genome size of A. rubrum was 1.69 Gb with an N50 of 549.44 Kb, and a total of 39 pseudochromosomes were generated with a 99.61% genome. The A. rubrum genome was predicted to have 64644 genes, of which 97.34% were functionally annotated. Genome annotation identified 67.14% as the transposable element (TE) repeat sequence, with long terminal repeats (LTR) being the richest (55.68%). Genome evolution analysis indicated that A. rubrum diverged from A. yangbiense ∼6.34 million years ago. We identified 13 genes related to pigment synthesis in A. rubrum leaves, where the expressions of four ArF3′H genes were consistent with the synthesis of cyanidin (a key pigment) in red leaves. Correlation analysis verified that the pigmentation of A. rubrum leaves was under the coordinated regulation of non-structural carbohydrates and hormones. The genomic sequence of A. rubrum will facilitate genomic breeding research for this species, while providing the valuable utilization of Aceraceae resources.

THE ROLE OF CATESTATIN IN THE REGULATION OF METABOLIC DISORDERS. Review

Relevance. Cardiovascular diseases occupy leading positions in the structure of morbidity and mortality both in Ukraine and in other countries. Metabolic disorders are one of the leading risk factors for the development and progression of cardiovascular diseases. In accordance with the above-mentioned special attention should be paid to catestatin, which regulates carbohydrate and lipid metabolism, that determines its diagnostic potential in the management of diseases, which are accompanied by metabolic dysregulation.&#x0D; Objective: Determination of the diagnostic potential of catestatin in the management of diseases associated with metabolic disorders such as type 2 diabetes mellitus, obesity and metabolic syndrome, in accordance with its role in the regulation of metabolic homeostasis based on the analysis of data literature sources.&#x0D; Methods. Analysis of the research results by reviewing electronic scientometric databases PubMed and Google Scholar by keywords.&#x0D; Results. The influence of catestatin on the pathogenetic mechanisms of cardiometabolic diseases is analyzed. The general characteristic of catestatin and its physiological properties is given. The effect of catestatin on carbohydrate metabolism due to its insulin-like action is studied, which in combination with antioxidant, immunomodulatory and anti-inflammatory action of catestatin determines its role in the regulation of glucose metabolism. The property of catestatin to regulate cardiometabolic homeostasis by modulating the bioenergetic activity of the myocardium is noted. Mechanisms of regulation of fat metabolism by catestatin are established, in particular, realization of its lipolytic effect due to suppression of α2-adrenoreceptors and regulation of adrenergic and leptin signaling. Correlations between catestatin levels and lipid profile and anthropometric data are considered. Typical changes in catestatin levels at the development of cardiometabolic diseases are defined.&#x0D; Conclusions. Catestatin has metabolic effects, in particular, participates in the regulation of carbohydrate and lipid metabolism, which determines its prognostic role in the development and progression of cardiometabolic diseases.

Integrated application of transcriptomics and metabolomics provides insights into condition index difference mechanisms in the Pacific oyster (Crassostrea gigas)

The condition index (CI) is an economically important tool for assessing the quality of oysters, such as the Pacific oyster Crassostrea gigas. However, little is known about the mechanisms that underlie differences in CI between different C. gigas populations. In this study, we integrated transcriptomic and metabolomic profiling to investigate the mechanisms that underlie the differences between high- and low-CI groups in one- and two-year-old populations of C. gigas. The results indicate that differences in CI were associated with the regulation of growth-related genes, the FoxO signaling pathway, and the complex regulation of carbohydrate, lipid, amino acid, and energy metabolism. Moreover, the mechanisms underlying these differences differed between the populations. This study is the first to elucidate the molecular and chemical mechanisms associated with CI, and the results will be helpful for breeding higher quality oysters.

A broadly applicable, stress-mediated bacterial death pathway regulated by the phosphotransferase system (PTS) and the cAMP-Crp cascade

Recent work indicates that killing of bacteria by diverse antimicrobial classes can involve reactive oxygen species (ROS), as if a common, self-destructive response to antibiotics occurs. However, the ROS-bacterial death theory has been challenged. To better understand stress-mediated bacterial death, we enriched spontaneous antideath mutants of Escherichia coli that survive treatment by diverse bactericidal agents that include antibiotics, disinfectants, and environmental stressors, without a priori consideration of ROS. The mutants retained bacteriostatic susceptibility, thereby ruling out resistance. Surprisingly, pan-tolerance arose from carbohydrate metabolism deficiencies in ptsI (phosphotransferase) and cyaA (adenyl cyclase); these genes displayed the activity of upstream regulators of a widely shared, stress-mediated death pathway. The antideath effect was reversed by genetic complementation, exogenous cAMP, or a Crp variant that bypasses cAMP binding for activation. Downstream events comprised a metabolic shift from the TCA cycle to glycolysis and to the pentose phosphate pathway, suppression of stress-mediated ATP surges, and reduced accumulation of ROS. These observations reveal how upstream signals from diverse stress-mediated lesions stimulate shared, late-stage, ROS-mediated events. Cultures of these stable, pan-tolerant mutants grew normally and were therefore distinct from tolerance derived from growth defects described previously. Pan-tolerance raises the potential for unrestricted disinfectant use to contribute to antibiotic tolerance and resistance. It also weakens host defenses, because three agents (hypochlorite, hydrogen peroxide, and low pH) affected by pan-tolerance are used by the immune system to fight infections. Understanding and manipulating the PtsI-CyaA-Crp–mediated death process can help better control pathogens and maintain beneficial microbiota during antimicrobial treatment.

Proteomics analysis of the hypothalamus of high-fat diet fed mice after Lactiplantibacillus plantarum Y44 administration

Probiotics could regulate human health via changing gut microbiota. Our previous studies found that Lactiplantibacillus plantarum Y44 (L. plantarum Y44) was shown to reverse obesity-related symptoms of high-fat diet fed mice by influencing gut microbiota, which ameliorated lipid metabolism disorders and intestinal inflammation. In this study, the effects of L. plantarum Y44 on high-fat fed mice and the involved mechanisms were investigated through hypothalamus proteomics analysis, which revealed 22 downregulated and 21 upregulated proteins. Differentially expressed proteins between L. plantarum Y44 intervention group and high-fat fed group in hypothalamus of mice involved in metabolic pathways were concentrated in endocrine regulation of carbohydrate, amino acid and energy generation pathways. The hypothalamus proteomics results about the influences on most of differentially expressed proteins of L. plantarum Y44 administering high-fat fed mice has been verified. Therefore, L. plantarum Y44 would be a potential functional strain for the amelioration of high-fat diet associated health problems.

Carbohydrate regulation response to cold during rhizome bud dormancy release in Polygonatum kingianum

BackgroundThe rhizome of Polygonatum kingianum Coll. et Hemsl (P. kingianum) is a crucial traditional Chinese medicine, but severe bud dormancy occurs during early rhizome development. Low temperature is a positive factor affecting dormancy release, whereas the variation in carbohydrates during dormancy release has not been investigated systematically. Therefore, the sugar content, related metabolic pathways and gene co-expression were analysed to elucidate the regulatory mechanism of carbohydrates during dormancy release in the P. kingianum rhizome bud.ResultsDuring dormancy transition, starch and sucrose (Suc) exhibited opposing trends in the P. kingianum rhizome bud, representing a critical indicator of dormancy release. Galactose (Gal) and raffinose (Raf) were increased in content and synthesis. Glucose (Glc), cellulose (Cel), mannose (Man), arabinose (Ara), rhamnose (Rha) and stachyose (Sta) showed various changes, indicating their different roles in breaking rhizome bud dormancy in P. kingianum. At the beginning of dormancy release, Glc metabolism may be dominated by anaerobic oxidation (glycolysis followed by ethanol fermentation). After entering the S3 stage, the tricarboxylic acid cycle (TCA) and pentose phosphate pathway (PPP) were may be more active possibly. In the gene co-expression network comprising carbohydrates and hormones, HYD1 was identified as a hub gene, and numerous interactions centred on STS/SUS were also observed, suggesting the essential role of brassinosteroids (BRs), Raf and Suc in the regulatory network.ConclusionWe revealed cold-responsive genes related to carbohydrate metabolism, suggesting regulatory mechanisms of sugar during dormancy release in the P. kingianum rhizome bud. Additionally, gene co-expression analysis revealed possible interactions between sugar and hormone signalling, providing new insight into the dormancy release mechanism in P. kingianum rhizome buds.

Geometric analysis of macronutrient selection and balancing in the superworm, Zophobas atratus

AbstractThe larvae of Zophobas atratus F. (Coleoptera: Tenebrionidae) are a promising source of dietary protein for animal feed. However, there has been no detailed investigation on macronutrient selection and requirement in Z. atratus larvae. Here, we used the geometric framework to explore the behavioural and physiological regulation of protein and carbohydrate in Z. atratus larvae. When provided with pairs of nutritionally imbalanced but complementary foods (choice experiment), Z. atratus larvae self‐composed a diet with a protein‐to‐carbohydrate (P:C) ratio of 1.47:1 or 1.19:1 throughout the experimental period. Across different choice combinations, the intake of carbohydrate was more tightly regulated than that of protein. When confined to one of six foods imbalanced with respect to P:C ratio (no‐choice experiment), Z. atratus larvae regulated their protein–carbohydrate intake to form linear intake arrays across nutrient space in a manner similar to those previously described for other nutritional generalists. The negative slope of the linear intake arrays was shallow (−0.67 to −0.54), suggesting that protein was over‐consumed by Z. atratus larvae to a greater extent than carbohydrates. The nutritional landscapes fitted for larval performance traits exhibited that the performance of Z. atratus larvae was maximized at the P:C ratio of 2:1 and fell rapidly as the P:C ratio decreased below 1:1. There was evidence for post‐ingestive regulation for body nutrient growth through adjusting the utilization efficiencies of ingested protein and carbohydrate. Our results represent the most comprehensive analysis of macronutrient regulation in Z. atratus and have implications for designing an optimal diet for this beneficial insect.

Understanding nutritive need in Harmonia axyridis larvae: Insights from nutritional geometry.

The multicolored Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), is an important natural enemy in agricultural ecosystems. In spite of being a carnivore consuming protein-rich preys, the lady beetles often consume carbohydrate-rich food like nectar or honeydew. However, most studies on nutrition regulation of carnivores mainly focus on protein and lipid, two major macronutrients in preys. In this study, nutrition regulation of protein and carbohydrate has been investigated in the 4th instar larvae of H. axyridis using Geometric Framework. We provided the insects two pairs of foods, one a protein-biased one and the second carbohydrate-biased, to determine the intake target. We then confined them to nutritionally imbalanced foods to examine how they regulated food intake to achieve maximal performance. The larvae performed well on the 2 foods that containing the closest P:C ratios to the intake target, but, surprisingly, the lipid content was much lower than that in the choice experiment. The lady beetles seemed to maintain the optimal lipid content by consuming carbohydrate-rich food. Moreover, consuming the carbohydrate-rich food was less metabolically expensive than the protein-rich food. Therefore, switching behavior between plant and animal foods actually reflects their nutritive needs. These findings extended our understanding of predator forage behavior and its influence on food web in ecosystems, and shed light on the role of agri-environment schemes in meeting the nutritional need of predators in field.

Early Lipid Metabolic Effects of the Anti-Psychotic Drug Olanzapine on Weight Gain and the Associated Gene Expression.

BackgroundAtypical antipsychotics such as olanzapine often cause metabolic side effects such as obesity and diabetes, leading to an increased risk of nonalcoholic fatty liver disease. The aim of the present study was to investigate the effects of olanzapine treatment on hepatic lipid metabolism and its possible relationship with adipose tissue status.MethodsUsing a female rat model, we investigated the effects of chronic olanzapine administration on the regulation of carbohydrate and lipid metabolism including lipid biosynthesis, oxidation, efflux, and lipolysis in liver and adipose tissue.ResultsThe body weight, liver mass and visceral adiposity after olanzapine treatment (2 mg/kg) for five weeks were not significantly different compared with vehicle controls. The serum level of triglycerides was higher in the vehicle controls than in olanzapine-treated rats. Unexpectedly, olanzapine treatment did not reduce glucose tolerance in our model. The expression of functional thermogenic protein uncoupling protein 1 (UCP1) was increased in brown adipose tissue (BAT) of the olanzapine group. Additionally, olanzapine treatment also reduced adipose inflammation in white adipose tissue (WAT). The transcription factor sterol regulatory element-binding protein (SREBP)-1c, a key early regulator of lipogenesis, was downregulated following olanzapine treatment. The expression of genes related to the triglycerides synthesis apparatus in the liver was upregulated in the olanzapine group. Olanzapine treatment induced genes involved in PPAR-α signaling and mitochondrial fatty acid oxidation in response to increased ATGL-mediated lipolysis in the liver.ConclusionTogether, our findings suggest a complicated link between olanzapine therapy and metabolic disturbance and may garner interest in assessing the action of antipsychotic-induced metabolic disturbances.

Potential Carbohydrate Regulation Mechanism Underlying Starvation-Induced Abscission of Tomato Flower.

Tomato flower abscission is a critical agronomic problem directly affecting yield. It often occurs in greenhouses in winter, with the weak light or hazy weather leading to insufficient photosynthates. The importance of carbohydrate availability in flower retention has been illustrated, while relatively little is understood concerning the mechanism of carbohydrate regulation on flower abscission. In the present study, we analyzed the responding pattern of nonstructural carbohydrates (NSC, including total soluble sugars and starch) and the potential sugar signal pathway involved in abscission regulation in tomato flowers under shading condition, and their correlations with flower abscission rate and abscission-related hormones. The results showed that, when plants suffer from short-term photosynthesis deficiency, starch degradation in flower organs acts as a self-protection mechanism, providing a carbon source for flower growth and temporarily alleviating the impact on flower development. Trehalose 6-phosphate (T6P) and sucrose non-fermenting-like kinase (SnRK1) signaling seems to be involved in adapting the metabolism to sugar starvation stress through regulating starch remobilization and crosstalk with IAA, ABA, and ethylene in flowers. However, a continuous limitation of assimilating supply imposed starch depletion in flowers, which caused flower abscission.

Announcing the 2021 Journal of Experimental Biology Outstanding Paper Prize shortlist and winner.

Announcing the 2021 Journal of Experimental Biology Outstanding Paper Prize shortlist and winner.