Total Amino Acid Levels Research Articles

Growth, biochemical composition, and photosynthetic performance of Scenedesmus acuminatus during nitrogen starvation and resupply

Many microalgae store energy as triacylglycerols under certain environmental conditions. Nitrogen limitation is recognized as an efficient lipid-accumulation trigger in microalgae. Here, biochemical composition (lipids, carbohydrates, and soluble proteins) time courses, fatty acid composition, pigment accumulation, and the photosynthetic efficiency of photosystem II (PSII) in Scenedesmus acuminatus were investigated under nitrogen starvation and resupply conditions. This work provides a theoretical basis for how microalgae utilize nitrogen to optimize lipid production. Nitrogen starvation inhibits cell division and growth, and promote the accumulation of lipids and carbohydrates. The total lipid content under nitrogen starvation approached 50.12% of the dry weight and neutral lipids accounted for 92.55% of the total lipids. Upon NaNO3 supplementation at day 9, the maximum photosynthesis efficiency (Fv/Fm), and the total amino acid, soluble protein, and pigment levels recovered rapidly within the first 12 h, while the degraded carbohydrate served as a carbon and energy source. After a 2-day lag time (from days 9 to 11), the biomass increased rapidly. The biomass concentration and lipid content reached 4.24 g L−1 and 36.46% of dry weight, respectively, at the end of cultivation. The Chla and Chlb contents of S. acuminatus were more sensitive than the carotenoid content to environmental nitrogen sources. The change in non-photochemical quenching (NPQ) was complicated, significantly increasing to a peak and then decreasing during both nitrogen starvation and recovery.

Effect of incremental levels of dietary total sulfur amino acids on performance of white leghorn laying hens fed diets containing guar (Cyamopsis tetragonoloba) meal.

The present study evaluated the potential of increasing dietary levels of the most limiting amino acids such as total sulfur amino acids (TSAA) with respect to mitigating the adverse effects of the inclusion of guar meal (GM) in the diet of WL layers on egg production, feed efficiency and egg weight. In total, 4928 WL (Lohmann L) hens (32 week of age) were randomly allotted to eight treatments with seven replicates of 88 birds. The dietary treatments were a set of four maize-soybean meal based diets containing four graded concentrations of TSAA (5.85, 6.18, 6.51 and 6.84 g kg-1 ) and another set of four diets containing 100 g kg-1 guar meal (GM) with similar concentrations of TSAA. The inclusion of 100 g kg-1 GM in the diet caused a 20%, 23%, 35.5% and 6.7% reduction in egg production, daily egg mass, feed efficiency and egg weight, respectively, when the diet contained 5.85 g kg-1 TSAA. Increasing TSAA levels in GM groups reduced the adverse effects on egg production and feed efficiency 50%, with no effect on egg weight. The TSAA requirement of WL birds fed 10% GM was estimated as 6.28-7.39 g kg-1 diet at different ages. Increasing dietary TSAA to 7.39, 6.28, 6.53 and 6.37 g kg-1 or dTSAA (digestible TSAA) to 6.53, 5.32, 5.80 and 5.63 g kg-1 during 33-36, 37-40, 41-44 and 45-48 weeks of age, respectively, may be an effective and practical strategy for reducing the adverse effects of inclusion of 100 g kg-1 GM in the diet of WL layers. © 2018 Society of Chemical Industry.

Extracts from Yeast and Carrot Roots Enhance Maize Performance under Seawater-Induced Salt Stress by Altering Physio-Biochemical Characteristics of Stressed Plants

Damage to plant productivity due to soil salinity is a major agricultural problem, necessitating the development of effective salinity management measures. Here, we sought the potential effects of yeast and carrot extracts, and their associated mechanisms in the alleviation of seawater-induced salt stress in maize. Pretreatment of maize seeds with yeast or carrot extract provided maize plants with enormous abilities in reducing growth inhibition and biomass loss when exposed to seawater. The better growth performance of yeast extract- and carrot extract-primed plants under saline conditions coincided with improved protection of the photosynthetic pigments, chlorophylls and carotenoids. The primed plants also restricted Na+ accumulation in both roots and shoots while maintaining a higher K+ content and lower Na+/K+ ratio when compared with that of non-primed plants. Yeast extract and carrot extract also potentiated salt tolerance mechanisms by accelerating the production of osmolytes, as evidenced by accumulating levels of total free amino acids and soluble sugars, especially in the roots of primed plants during salinity. The enhanced levels of ascorbic acid and phenolic compounds, and the heightened activities of reactive oxygen species-detoxifying enzymes superoxide dismutase, catalase, and ascorbate peroxidase with concurrent reduction of lipid peroxidation in the leaves of primed plants clearly indicated a positive impact of yeast extract- and carrot extract-priming on the antioxidant system of maize under salt stress. Our results together suggest decisive roles of yeast extract and carrot extract in the management of salt-induced adverse effects in economically important maize, and perhaps other crops.

Plasma Levels of Amino Acids in Japanese Men and Their Changes after the Administration of Glucose and Sucrose

Background: It is not known whether plasma amino acids levels are different between young and old men in Japan. No research has been reported about changes in plasma levels of amino acids after the administration of glucose or sucrose to young and aged men. Objective: We want to know whether there are age differences in plasma levels of amino acids and if the administration of glucose or sucrose influences their levels. Results: Old people had lower plasma levels of most of amino acids, especially essential and branched-chain amino acids than young men. Plasma levels of amino acids were measured after the administration of 50 grams of glucose or sucrose to young (18 - 22 years old) and aged (≥50 years old) male adults. Plasma levels of total amino acids decreased after the administration of glucose. Decrease in the total amino acid levels was significant in aged men after the administration of sucrose. A significant decrease in plasma levels of total non-essential amino acids was observed at 120 min after the administration of glucose but not sucrose in both aged and young men. Both glucose and sucrose administrations resulted in a significant decrease in the plasma levels of the total essential amino acid levels and branched amino acids in young and aged men. Conclusion: These results suggest that there are age differences in plasma levels of amino acids. Upon the administration of glucose or sucrose amino acids, particularly essential amino acids, decreased in plasma. These amino acids may be transported from the blood soon after the administration of sugar (glucose or sucrose) to the tissues, such as muscles, possibly due to an increase in the insulin levels.

Environmental Conditions and Species Identity Drive Metabolite Levels in Green Leaves and Leaf Litter of 14 Temperate Woody Species

Research Highlights: Leaf chemistry is a key driver of litter decomposition; however, studies directly comparing metabolites that are important for tree growth and defence across different woody species are scarce. Background and Objectives: Choosing 14 temperate woody species differing in their growth rates, nutrient demand, shade tolerance, and drought sensitivity, we hypothesized that the species would group according to their metabolite profiles based on their ecological background. Materials and Methods: We analysed total N and C, soluble amino acid, protein, and phenolic levels in green leaves and leaf litter of these species, each in two consecutive years. Results: Metabolite levels varied significantly across species and between the sampling years which differed in temperature and precipitation (i.e., colder/drier vs warmer/ wetter). Conclusions: The 14 woody species could not be grouped according to their green leaf or leaf litter metabolite profiles. In litter leaves, most of the variation was explained by total phenolics and total nitrogen levels, and in green leaves by total phenolics and total soluble amino acid levels. Local climate variation between the two consecutive years for green leaves or leaf litter led to significant differences in metabolite levels, although some of them were species-specific.

Effects of periodical drying and non-drying on nutrient content and desiccation tolerance of an intertidal Pyropia yezoensis strain subject to farming conditions

Aquaculture of Pyropia yezoensis is extending from shallow seawater to deep seawater in China where full-floating culture protocol is applicable. The current P. yezoensis cultivars come from intertidal parents and have been long subject to periodical drying (PD) culture protocols. To investigate whether these cultivars acclimate to a full-floating non-drying (ND) culture protocol, an intertidal P. yezoensis cultivar was cultured with ND and PD protocols. It was found that protocols with and without PD affected dehydration tolerance and nutrient components differently during farming. The maximum quantum yield of PSII (Fv/Fm) of the thalli from both systems decreased during dehydration. During rehydration, Fv/Fm of the thalli from the PD system fully recovered after 70% relative water loss (RWL), whereas Fv/Fm of the thalli from the ND system failed to fully recover from 50% RWL. During dehydration, superoxide dismutase, peroxidase, and catalase activities in the thalli cultured with ND were much lower than those in the thalli from PD systems. Nevertheless, the activity of superoxide dismutase + peroxidase + catalase was similar in the fresh thalli from both systems. Compared to the PD system, the thalli from the ND system contained lower levels of soluble proteins, chlorophyll a, carotenoids, total fatty acids (FA), and C16:0 FA but higher levels of total amino acids (AA), delicious AA, unsaturated FA, and eicosapentaenoic acid. Contents of phycocyanin, allophycocyanin, and essential AA were similar in both systems. In summary, there were pros and cons of using either system for P. yezoensis cultivation. Diversified Pyropia culture protocols should be applied depending on seawater depth and requirements of varying nutrient components.

Improvement of protein quality and degradation of allergen in soybean meal fermented by Neurospora crassa

The nutrition quality and bioactivity of soybean meal was investigated via solid-state fermentation using Neurospora crassa (NC) alone or Neurospora crassa and saccharomyces cerevisiae (NCSC) together. The optimized fermentation conditions of NC or NCSC were obtained as follow: fermentation temperature (30 °C both), fermentation time (72 h vs 74.7 h), solid-liquid ratio [1:3.5 vs 1:3.0 (g/mL)], inoculation amount (the inoculation amount of fungi/soybean meal (dry weight)) of Neurospora crassa + Saccharomyces [1% (m/m)+0 vs 1% (m/m) +20% (v/m)], initial pH (7.0 both). The protein hydrolysis of fermented soybean meal (FSM) could reach to 10.05% and 8.05% by NC and NCSC, respectively. In fermented soybean meal by NC, the level of total free amino acids (TFAA) increased 13 times (p < 0.05), in vitro digestion rate of protein reached to 95.96%, increased by 37.97% (p < 0.05) compared to soybean meal (SM). In fermented soybean meal by NCSC, the level of TFAA increased 6.76 times than that in SM (p < 0.05). SDS-PAGE results showed that macromolecular proteins were degraded to micromolecular proteins (<14.4 kDa/mw). No stripe of antibody response was observed and IC50 values of allergic reaction were significantly increased. It indicated fermentation improved nutritional quality and antioxidant activity of SM, and may be applied to food materials.

Atmospheric pCO2 impacts leaf structural and physiological traits in Quercus petraea seedlings.

Atmospheric p CO 2 impacts Quercus petraea biomass production and cell wall composition of the leaves in favor of cellulose at the expense of lignin, and enhances foliar non-structural carbohydrate levels and sucrose contents in a pCO 2 concentration-dependent manner. Sessile oak (Quercus petraea Liebl.) was grown for ca. half a year from seeds at ambient control (525ppm), 750, 900, and 1000ppm atmospheric pCO2 under controlled conditions. Increasing pCO2 enhanced biomass production, modified the cell wall composition of the leaves in favor of cellulose at the expense of lignin, and enhanced the foliar non-structural carbohydrate level, in particular the sucrose content; as well as total N content of leaves by increased levels of all major N fractions, i.e., soluble proteins, total amino acids, and structural N. The enhanced total amino acid level was largely due to 2-ketoglutarate and oxalo acetate-derived compounds. Increasing pCO2 alleviated oxidative stress in the leaves as indicated by reduced H2O2 contents. High in vitro glutathione reductase activity at reduced H2O2 contents suggests enhanced ROS scavenging, but increased lipid peroxidation may also have contributed, as indicated by a negative correlation between malone dialdehyde and H2O2 contents. Almost all these effects were at least partially reversed, when pCO2 exceeded 750 or 900ppm. Apparently, the interaction of atmospheric pCO2 with leaf structural and physiological traits of Q. petraea seedlings is characterized by a dynamic response depending on the pCO2 level.

Mould starter selection for extended solid-state fermentation of quinoa

Solid-state fermentation of plant materials with food grade moulds is considered a method of obtaining bioactive food products and additives. However, the use of quinoa seeds as a substrate in such a process has not been thoroughly studied to date. In this paper, extended fermentation with Rhizopus oligosporus, Aspergillus oryzae and Neurospora intermedia (tempe, koji and oncom moulds, respectively) was performed in order to enhance the antioxidant potential of coloured quinoa (as measured by the total soluble phenols, ABTS˙+ and ˙OH scavenging activities, and the reducing power).The most efficient of the examined strains was Rhizopus, which caused an average improvement in the aforementioned qualities of 220% (black seeds) and 129% (red seeds), as compared to pre-cooked seeds. Four-day fermentation with Rhizopus resulted in a drastically enhanced amount of vanillin in the free phenolic fraction (130-fold in black quinoa seeds). However, the overall level of free and bound phenolics (as measured by the HPLC-DAD-ESI-TOF-MS method) in the material decreased. Both total peptides and individual free amino acid levels were significantly increased, which corresponded with the high antioxidant potential of the material. The fermented quinoa was also significantly enriched with total dietary fibre with dominant insoluble fraction.

Effect of Botanical Extracts on Amino Acid and Fatty Acid Profile of Broiler Meat

ABSTRACT The objectives of current study were to evaluate the effect of botanical extracts as antioxidants on amino - and fatty acids profile of broiler meat. In total, 200 one-day-old broiler chicks were divided according to a completely randomized design into eight dietary treatments with five replicates of five chicks each. Dietary treatments were: A - positive control (PC) with antibiotics and synthetic antioxidants, B - negative control (NC), C - NC+Trigonellafoenum-graecum, D -NC+Nigella sativa seed, E -NC+Violaodorata, F -NC+Trachyspermumammi, G -PC+Trachyspermumammi+Trigonellafoenum-graecum+Violaodorata, and H -NC+ Trachyspermumammi, Trigonellafoenum-graecum and Viola odorata. Meat amino - and fatty acid contents were analyzed after slaughter at 35 days of age. Data were submitted to one-way analysis of variance and means were compared by Duncan’s Multiple Range test. The levels of histidine, isoleucine, leucine, lysine and threonine were significantly higher (p≤0.05) in the H, F, E, H and F groups respectively. Arginine, tryptophan, valine, methionine, and phenylalanine were significantly higher (p≤0.05) in the C, F, E, G and H groups. Total essential amino acid levels were highest (40.36%) in C group (p≤0.05). The meat of H broilers presented significantly higher (p≤0.05) unsaturated fatty acids (54.8%) and omega-3 contents (2.77%) and the lowest saturated fatty acid content (44.8%). Group F present the highest linoleic acid and omega-6 levels and group H the highest (p≤0.05) arachidonic and eicosapentaenoic acid (EPA) contents. It was concluded that botanical extracts aid health-beneficial meat production and the simultaneous inclusion of Trachyspermumammi, Trigonellafoenum-graecum, and Viola odorata in broiler diets is a more suitable option than the other dietary regimes.

Evaluation of bitter melon (Momordica charantia) cultivars grown in Texas and levels of various phytonutrients.

In the USA, Momordica charantia is relatively unknown and is usually found in specialty markets. In the present study, cultivation of five bitter melon cultivars grown under field conditions in College Station (TX, USA), was evaluated. Additionally, ascorbic acid, amino acids and phenolic compounds were quantified from various cultivars grown in different years. The yield of the first year of evaluation was comparable to other bitter melon growing regions, ranging from 9371.5kg ha-1 for the Japanese Spindle cultivar to 20 839.1kg ha-1 for the Hong Kong Green cultivar. Multivariate analysis suggests a strong correlation between yield and growth degree days, water use efficiency and organic matter, as well as an inverse correlation with the amount or precipitation during the growing season. The highest levels of total ascorbic acid were shown in the Japanese Spindle cultivar (162.97 mg 100 g-1 fresh fruit), whereas the lowest levels were expressed in the Hong Kong Green cultivar (42.69 mg 100 g-1 fresh fruit). The highest levels of total phenolics were consistently found the Indian White cultivar, in the range 10.6-12.5mg g-1 catechin equivalents. Seven phenolics and organic acids were identified and quantified by liquid chromatography-mass spectrometry and high-performance liquid chromatography, respectively. Additionally, the highest levels of total amino acids were found in the Large Top cultivar. The current 3-year field study demonstrates that it is feasible to grow bitter melon commercially in Texas with proper climatic and agronomic conditions. Bitter melon is a rich source for ascorbic acid, amino acids and phenolic compounds, which makes it a valuable food source with respect to improving human health. © 2018 Society of Chemical Industry.

Optimization on Fermentation Process of Protein Concentrate of Jatropha Seed Cake with N Sources and Minerals Supplementation

The objective of this research is to produce alternative food sources of protein by optimizing the potential of jatropha curcas which is agroindustry waste. This study is planned in two years and is a series of jatropha seed exploration through fermentation using Lactobacillus acidophilus. Specific targets in the first year of study were to assess the optimization of the fermentation process by supplementing the source of N soybean meal and fish meal. Experiments using Completely Randomized Design (RAL) factorial pattern with first factor was supplementation (F) and second factor was incubation time (W), fermentation optimization consisted of: F1 (F0 + 2.5% soybean meal flour), F2 (F0 + 2.5% fish meal), F3 (F1 + 0.45% Dicalsium Phosphat) and F4 (F2 + 0.45% Dicalsium Phosphat). The incubation time is differentiated W1: 3 days, W2: 5 days and W3: 7 days. It can be concluded that: dry matter, gross energy, calcium and phospor are influenced by interaction between type of supplementation of source of N + DCP with fermentation time, whereas fat content is only influenced by fermentation time with optimal time decrease of fat content is 5,92 days. Total protein and amino acid levels are only influenced by different types of supplementation. Phorbolester antinutrition levels are influenced by the duration of the fermentation. Based on antinutritive as a limiting factor. F4W5 is the best treatment and can used as a feed ingredient.

Very high intact-protein formula successfully provides protein intake according to nutritional recommendations in overweight critically ill patients: a double-blind randomized trial

BackgroundOptimal energy and protein provision through enteral nutrition is essential for critically ill patients. However, in clinical practice, the intake achieved is often far below the recommended targets. Because no polymeric formula with sufficient protein content is available, adequate protein intake can be achieved only by supplemental amino acids or semi-elemental formula administration. In the present study, we investigated whether protein intake can be increased with a new, very high intact-protein formula (VHPF) for enteral feeding.MethodsIn this randomized, controlled, double-blind, multicenter trial, 44 overweight (body mass index ≥ 25 kg/m2) intensive care unit patients received either a VHPF (8 g/100 kcal) or a commercially available standard high protein formula (SHPF) (5 g/100 kcal). Protein and energy intake, gastrointestinal tolerance (gastric residual volume, vomiting, diarrhea, and constipation), adverse events, and serious adverse events were recorded. Total serum amino acid levels were measured at baseline and day 5.ResultsThe primary outcome, protein intake at day 5, was 1.49 g/kg body weight (95% CI 1.21–1.78) and 0.76 g/kg body weight (95% CI 0.49–1.03, P < 0.001) for VHPF and SHPF, respectively. Daily protein intake was statistically significantly higher in the VHPF group compared with the SHPF group from day 2 to day 10. Protein intake in the VHPF group as a percentage of target (1.5 g/kg ideal body weight) was 74.7% (IQR 53.2–87.6%) and 111.6% (IQR 51.7–130.7%) during days 1–3 and days 4–10, respectively. Serum amino acid concentrations were higher at day 5 in the VHPF group than in the SHPF group (P = 0.031). No differences were found in energy intake, measures of gastrointestinal tolerance, and safety.ConclusionsEnteral feeding with VHPF (8 g/100 kcal) resulted in higher protein intake and plasma amino acid concentrations than an isocaloric SHPF (5 g/100 kcal), without an increase in energy intake. This VHPF facilitates feeding according to nutritional guidelines and is suitable as a first-line nutritional treatment for critically ill overweight patients.Trial registrationNetherlands Trial Register, NTR5643. Registered on 2 February 2016.

Nutritional comparison in muscle of wild, pond and factory cultured Japanese flounder (Paralichthys olivaceus) adults

Muscle proximate composition, amino acid profiles, fatty acid compositions and selected minerals of wild, pond and factory cultured Japanese flounder adults were compared in this study to elucidate their nutritive values and dietary nutrition requirements. Wild and pond cultured Japanese flounder flesh had higher crude proteins, but crude lipid contents of factory cultured fish were 3.8~4.0 fold greater. Major amino acids in Japanese flounder were aspartic acid, glutamic acid and lysine. Wild fish had higher levels of total amino acids, essential amino acids, nonessential amino acids and half-essential amino acids and the contents in pond cultured samples were similar. Arachidonic acids (ARA), eicosapentaenoic acids (EPA), docosahexaenoic acids (DHA), polyunsaturated fatty acids (PUFA), DHA + EPA and n–3 PUFA in wild Japanese flounder were significantly higher than that in factory cultured fish, whereas fatty acid levels were close between pond cultured and wild fish. Japanese flounder were rich in zinc, iron and selenium, but poor in copper, chromium and nickel. Results indicated wild Japanese flounder had higher nutritional value and better meat quality, but the nutritional compositions of pond cultured fish were close to wild Japanese flounder, which suggested that pond culture of Japanese flounder offers broad application prospects.

Digestive proteases and in vitro protein digestibility of feed ingredients for the Central American river turtle, Dermatemys mawii.

Functional characteristics of digestive proteases and in vitro digestibility of several protein sources were studied in hatchlings of Central American river turtles, Dermatemys mawii. Acidic and alkaline proteases from the stomach and intestines were used, and optimums for acidic proteases were registered at 55°C and pH 2, while alkaline proteases were found at 55°C and pH 9. Ten protein ingredients, both vegetable and animal sources, were explored by the pH-STAT method, only for alkaline proteases. The degree of hydrolysis was at its highest for squid meal and lowest for blood meal, while the total free amino acids level was at its highest for squid meal, and lowest for wheat gluten meal. Our results indicate that D.mawii has a broad capacity to digest both animal and vegetable sources, and suggests some ingredients more suitable to design artificial diets for this species.

Selenium Accumulation, Antioxidant Enzyme Levels, and Amino Acids Composition in Chinese Mitten Crab (Eriocheir sinensis) Fed Selenium-Biofortified Corn.

The effects of selenium (Se)-biofortified corn on the total Se contents, the antioxidant enzyme levels, and the amino acids composition in Chinese mitten crab (Eriocheir sinensis) during the stage of the fifth shelling to maturity were investigated in the present study. The culture density of crabs was 600 per 667 m2, and they were continuously fed 120.4 mg Se from Se-biofortified corn per 667 m2 every two days for 90 days. The results showed that the total muscle Se levels in the crabs were significantly increased (p < 0.05). Activities of hemolymph supernatant enzymes including alkaline phosphatase (AKP), lysozyme (LZM), glutathione peroxidase (GPx), and superoxide dismutase (SOD) were also enhanced (p < 0.05). The protein and crude fat levels at maturity were higher than those at the fourth molt. The levels of total essential amino acids (∑EAAs) and total delicious amino acids (∑DAAs) were significantly increased (p < 0.05). We demonstrate that the feeding of Se-biofortified corn could significantly improve total muscle Se concentrations and hemolymph supernatant antioxidant enzyme activities in Chinese mitten crab, and slow down the rapid decline of ∑EAAs and ∑DAAs at maturity, thus improving the nutritional quality of Chinese mitten crab.

Variations in quality constituents of green tea leaves in response to drought stress under south Indian condition

Abstract Soil moisture stress seriously limits the growth and development of tea plants (Camellia sinensis), thus affecting crop yield and quality. Soil moisture reduction generally affects accumulation of tea secondary metabolites. To elucidate the variations in plant genotype response to abiotic stress during depleting soil moisture stress and changes in biochemical constituents of green leaf which determines the quality of black tea was investigated. An experiment was conducted at UPASI Tea Research Foundation Tea Research Institute, Distinctiveness-Uniformity-Stability center with drought tolerant clones namely UPASI-2, UPASI-6, UPASI-9, ATK-1, TRI-2025 and drought susceptible clones UPASI-3, UPASI-8, UPASI-17, TRF-1 of same age. Green leaves were collected from each plot was subjected to HPLC analysis for dihydroxyflavan-3-ols, trihydroxyflavon-3-ols and caffeine, and the results were statistically analyzed. The study indicated that the levels of total polyphenols, individual catechins, reducing sugars, amino acids and total lipids were significantly different at P ≤ .05 among the treatments. Caffeine level increased (P ≤ .05) with decrease in soil moisture for all the clones. Principal component analysis and hierarchical cluster analysis revealed differences between tea cultivars with respect to their quality and tolerance. Our study further indicated that the tolerant clones were able to accumulate higher levels of bio constituents during soil moisture stress than the susceptible ones. Quality of green tea leaf precursors is directly influenced by the soil moisture availability and is varietal dependent. This could be an important tool for the assessment of clonal performance and drought tolerance in tea cultivars.

Effects of acclimation to high environmental temperatures on intermediary metabolism and osmoregulation in the sub-Antarctic notothenioid Eleginops maclovinus

Eleginops maclovinus is a sub-Antarctic fish endemic to the South American coast and is a monotypic species of the Eleginopidae family. A scarce amount of scientific information exists regarding the effects of temperature on E. maclovinus physiology. In this study, E. maclovinus specimens were acclimated for 2 weeks at 10 °C (control), 14, and 18 °C. Posterior assessments were performed for the intermediary metabolism of carbohydrates, lipids, and amino acids (in the plasma, liver, gills, and kidney) and on the osmoregulatory capacity [plasma osmolality and gill, kidney, and foregut Na+, K+-ATPase (NKA) activities]. In the plasma, only lactate and total amino acid levels were affected by the temperature. NKA activity presented a linear relationship with the increased temperatures. The liver exhibited no change in the carbohydrates metabolism, but the glycogen/glucose metabolite levels did differ. Amino acid metabolism showed a direct relationship between temperature and GDH and Asp-AT activities, and an inverse relationship between temperature and Ala-AT activity. Lipid metabolism was similar to Ala-AT. In the gills, carbohydrate metabolism (G6PDH and HK activities) presented a direct relationship with the increased temperatures. In the kidney, carbohydrate metabolism (only G6PDH activity) was greater at higher temperatures, and amino acid metabolism (GDH activity) showed a direct relationship with temperature. Lipid metabolism (G3PDH activity) was greatest at 14 °C, presenting significant differences compared to 10 °C. The obtained results suggest that E. maclovinus can acclimate to the projected thermal increase of climate change, with a reorganization of the intermediary metabolism components being tissue-dependent and osmoregulatory effects being affected by NKA activity and greater rates of nitrogenous waste extrusion.

Drought stress promotes the colonization success of a herbivorous mite that manipulates plant defenses

Climate change is expected to bring longer periods of drought and this may affect the plant’s ability to resist pests. We assessed if water deficit affects the tomato russet mite (TRM; Aculops lycopersici), a key tomato-pest. TRM thrives on tomato by suppressing the plant’s jamonate defenses while these defenses typically are modulated by drought stress. We observed that the TRM population grows faster and causes more damage on drought-stressed plants. To explain this observation we measured several nutrients, phytohormones, defense-gene expression and the activity of defensive proteins in plants with or without drought stress or TRM. TRM increased the levels of total protein and several free amino acids. It also promoted the SA-response and upregulated the accumulation of jasmonates but down-regulated the downstream marker genes while promoting the activity of cysteine—but not serine—protease inhibitors, polyphenol oxidase and of peroxidase (POD). Drought stress, in turn, retained the down regulation of JA-marker genes and reduced the activity of serine protease inhibitors and POD, and altered the levels of some free-amino acids. When combined, drought stress antagonized the accumulation of POD and JA by TRM and synergized accumulation of free sugars and SA. Our data show that drought stress interacts with pest-induced primary and secondary metabolic changes and promotes pest performance.

Impact of germination on the chemical components and bioactive properties of adlay (Coix lachryma‐jobi L.) water extract

SummaryIn recent years, adlay water extract and related products have been widely consumed. This study investigated the chemical components and bioactive properties of adlay water extract at different germination stages. Glucose and maltose were significantly increased, whereas fructose was slightly decreased after germination. The contents of vitamins C and B1 in the water extract increased 1.61‐ and 2.68‐fold, respectively. The amounts of peptides, especially those with a molecular weight under 3000 Da, were significantly increased after germination. During germination, the level of total free amino acids rose from 54.09 to 128.22 μg mL−1, and the percentage of essential amino acids was elevated from 21.63% to 42.13%. Germination also substantially augmented the total phenolic content and antioxidant activity of the water extract. Moreover, the germinated adlay water extract showed higher inhibitory activity on angiotensin‐converting enzyme (ACE), xanthine oxidase and tyrosinase than the water extract of nongerminated adlay. These findings revealed that germination might be a potential way to improve the nutritional value and bioactive properties of adlay water extract.