Major Amino Acids Research Articles

Study on sentinel hosts for surveillance of future COVID-19-like outbreaks

The spread of SARS-CoV-2 to animals has the potential to evolve independently. In this study, we distinguished several sentinel animal species and genera for monitoring the re-emergence of COVID-19 or the new outbreak of COVID-19-like disease. We analyzed SARS-CoV-2 genomic data from human and nonhuman mammals in the taxonomic hierarchies of species, genus, family and order of their host. We find that SARS-CoV-2 carried by domestic dog (Canis lupus familiaris), domestic cat (Felis catus), mink (Neovison vison), and white-tailed deer (Odocoileus virginianus) cluster closely to human-origin viruses and show no differences in the majority of amino acids, but have the most positively selected sites and should be monitored to prevent the re-emergence of COVID-19 caused by novel variants of SARS-CoV-2. Viruses from the genera Panthera (especially lion (Panthera leo)), Manis and Rhinolophus differ significantly from human-origin viruses, and long-term surveillance should be undertaken to prevent the future COVID-19-like outbreaks. Investigation of the variation dynamics of sites 142, 501, 655, 681 and 950 within the S protein may be necessary to predict the novel animal SARS-CoV-2 variants.

An in-depth exploration of ethnomedicinal applications, phytochemical profiles, and pharmacological potentials: unveiling Withania somnifera

Researchers have extensively studied Withania somnifera (L.) Dunal, a woody shrub renowned for its multifaceted medicinal attributes such as antibacterial, anti-inflammatory, adaptogenic, aphrodisiac, and tonifying properties, because of its medicinal and traditional values. However, comprehensive information about its medicinal uses and pharmacological implications is scattered across various sources. Thus, this study aims to provide a comprehensive review of its ethnomedicinal uses, phytochemistry, and pharmacological attributes, consolidating information from diverse data sources. Systematic investigations have revealed the presence of diverse phytochemicals in W. somnifera, including major alkaloids, withanolides, flavonoids, tannins, oils, phytosterols, and amino acids. Extracts, fractions, and bioactive compounds derived from W. somnifera exhibited potent antibacterial, anti-inflammatory, anti-aging, anti-analgesic, anti-cancer, antivenom, anti-fungal, and anti-viral activities. W. somnifera serves as a valuable source of phytochemicals with diverse biological activities, offering significant therapeutic benefits globally. However, further studies are needed to assess potential side effects. Additionally, while several isolated compounds have demonstrated notable bioactivities, future research should focus on elucidating their mechanistic features to facilitate their integration into drug discovery endeavors.

Investigating the synergistic effect of fish waste extract and KI on the corrosion inhibition of carbon steel in sulfuric acid solution

Biowaste has become a serious problem that can lead to serious environmental pollution and waste of resources if not handled properly. Waste materials are often high in proteins, which are easily extracted and hydrolyzed to provide an adequate quantity of amino acids. This indicates that biowastes can be used as green and efficient corrosion inhibitors (CIs). This work aimed to prepare fish waste extract (FWE) by acid hydrolysis with alkaline leaching using fish waste as the raw material. The results of the characterization analysis identified the presence of 17 amino acids, with Leucine, Phenylalanine, Methionine, and Alanine being the most abundant. FWE was then tested as a corrosion inhibitor (CI) for carbon steel in 0.5 mol/L H2SO4. Further, the effect of KI on the corrosion inhibition performance of FWE for carbon steel in 0.5 mol/L H2SO4 was systematically investigated by the weight loss method, electrochemical method, and surface analysis. The maximum corrosion inhibition efficiencies were 88.7 % and 63.9 % for the FWE and KI alone, and 97.10 % for the combination of FWE and KI. The synergistic coefficient study confirmed that the synergistic coefficients of the FWE and KI exceeded 1 across all concentration conditions, indicating a synergistic effect between them. The surface analysis results showed that the deterioration of carbon steel after adding the compounded CI was mild, and pitting and crevice corrosion was not observed. Theoretical calculations revealed the active reaction sites of four major amino acid molecules via quantum chemical and molecular dynamics simulations. The effect of different types of side chains and heteroatoms of amino acid molecules on their corrosion inhibition performance was elucidated to provide theoretical guidance for designing biowaste CIs.

Гено-фенотипические особенности муковисцидоза у российских детей из Чеченской и Карачаево-Черкесской Республик

Background: Cystic fibrosis (CF) is an autosomal recessive disease that occurs with a frequency of 1:1,500 to 1:5,000 newborns, according to the World Health Organization. In the Russian Federation, the average incidence of the disease is 1:10,000 newborns. The medical and social significance of this disease is associated with the early disability of patients, the need for long-term treatment and constant follow-up, as well as the heterogeneity of phenotypic manifestations, which in turn requires early diagnosis using molecular genetic methods. The aim of the study: To study the clinical and molecular genetic characteristics of children with CF from the Chechen and Karachay-Cherkess Republics. Materials and methods: The study included 237 patients with a confirmed diagnosis of CF. Molecular genetic diagnostics was performed using the method of mass parallel sequencing using a hybridization target panel that includes the entire CFTR gene. Sequencing was performed on the MiSeq platform. All causal nucleotide variants were validated using Sanger sequencing. Results: The most common amino acid variants of the CFTR gene in patients with CF from the Chechen Republic are: p.Y515* (94 alleles/78.3%), p.E92K (18 alleles/15%). The presence of variants p.Y515* and p.E92K in the heterozygous state in the genotype is more often a favorable prognostic factor for the absence of pancreatic lesion. The main distinctive clinical feature of these patients is the onset of the disease with manifestations of pseudo-Bartter syndrome. The major amino acid variant of the CFTR gene in patients with CF from the Karachay-Cherkess Republic is: p.W1282* (28 alleles/70%). The number of patients with pseudo-Bartter syndrome was 54.5%. In 90% of cases, in patients who are homo- and heterozygous according to p.W1282*, a severe degree of pancreatic insufficiency was noted. Conclusion: Patients with cystic fibrosis from the Chechen and Karachay-Cherkess Republics are a difficult category of patients, despite neonatal screening, and cystic fibrosis therapy developed and implemented. This is partly due to the peculiarities of the phenotype and the unique distribution of alleles and genotypes of the CFTR gene. The high number of homozygous variants of the CFTR gene in patients from the Chechen and Karachay-Cherkess Republics is probably due to monoethnic marital assortativity.

A comprehensive physicochemical characterization and proposed portfolios of applications for the fruits and seeds of 11 accessions of Jatropha curcas L.

The seed oil and extraction cake from 11 accessions of Jatropha curcas from Mexico, El Salvador, and India were comprehensively characterized with the objective of selecting parentals based on desirable traits for a hybridization program. Kernels contained up to 65 % oil and up to 30 % protein. The most abundant protein types were glutelins (48 %) and globulins (24 %), with arginine (0.096 mg/g) and leucine (0.070 mg/g) being the major amino acids. Glucose (0.09 g/g) and arabinose (0.03 g/g) were the most abundant carbohydrates. The oil was primarily composed of oleic (41 %) and linoleic (37 %) acids. The physicochemical properties of the oil included an acid value of 0.28–1.15 %, saponification value of 155–208 mg KOH/g, iodine value of 0.97–1.08 g I2/g, and viscosity of 21.9–40.9 cSt at 40 °C. Six accessions were selected as parental candidates based on their potential as feedstock for a diverse portfolio of products. The most common applicability of oils were lubricants, biopolymers, biofertilizer, and liquid biofuels production. One Mexican accession had a phorbol-ester concentration much lower than the toxicity threshold (0.06 mg/g) and a high protein content, making it attractive for the animal feed industry and for protein extraction. The selected accessions are preserved in a local germplasm bank and will be used for continued genetic improvement through hybridization, aiming to preserve the identified traits while increasing fruit productivity.

Cisplatin-Induced Metabolic Responses Measured with Raman Spectroscopy in Cancer Cells, Spheroids, and Canine-Derived Organoids.

Ex vivo assessment of drug response with conventional cell viability assays remains the standard practice for guiding initial therapeutic choices. However, such ensemble approaches fail to capture heterogeneities in treatment response and cannot identify early markers of response. Here, we leverage Raman spectroscopy (RS) as an accurate, low-cost, extraction-free, and label-free approach to track metabolic changes in cancer cells, spheroids, and organoids in response to cisplatin treatment. We identified 12 statistically significant metabolites in cells and 19 metabolites in spheroids and organoids as a function of depth. We show that the cisplatin treatment of 4T1 cells and spheroids results in a shift in metabolite levels; metabolites including nucleic acids such as DNA, 783 cm-1 with p = 0.00021 for cells; p = 0.02173 for spheroids, major amino acids such as threonine, 1338 cm-1 with p = 0.00045 for cells; p = 0.01022 for spheroids, proteins such as amide III, 1248 cm-1 with p = 0.00606 for cells; p = 0.00511 for spheroids serve as early predictors of response. Our RS findings were also applicable to canine-derived organoids, showing spatial variations in metabolic changes as a function of organoid depth in response to cisplatin. Further, the metabolic pathways such as tricarboxylic acid (TCA)/citric acid cycle and glyoxylate and dicarboxylate metabolism that drive drug response showed significant differences based on organoid depth, replicating the heterogeneous treatment response seen in solid tumors where there is a difference from the periphery to the tumor core. Our study showcases the versatility of RS as a predictive tool for treatment response applicable from cells to organotypic cultures, that has the potential to decrease animal burden and readout time for preclinical drug efficacy.

Surface functionalization of graphene electrode using flavin AuNps for a realtime sensing of asparagine

Asparagine (ASN) is one of the major non-essential amino acids and helps to breakdown the toxic ammonia within the cell. The electrochemical detection of asparagine was performed by the surface functionalized screen-printed carbon (MSPEC) and screen-printed graphene electrodes (MSPEG) through flavin (Quercetin) based gold nanoparticles (AuNps). Cyclic voltammetry (CV) and Differential Pulse Voltammetry (DPV) were performed through MSPEC and MSPEG at single drop of analyte via DROPSENS. SEM and Electrochemical Impedance (EIS) examined for the surface characteristics, enhancement, and functionality of electrodes modified with flavin AuNps. The surface functionalized electrodes revealed excellent electrochemical sensor with high stability, selectivity, repeatability, and have a low limit detection of 0.001 nM. Also, sensors progression was found to occur through adsorption-controlled phenomena. The oxidation peak potential for asparagine in CV and DPV was well-expressed by the MSPEC and MSPEG, with potentials of +0.0881 V and +0.3141 V, respectively. Hence the flavin based AuNps is a new sensing platform for the consistent asparagine real-time sensor and the selective electrochemical detection of asparagine with an exceptionally low detection limit at one drop.

295 Synthesis of glycine from trans-4-hydroxy-L-proline in tissues of juvenile hybrid striped bass (Morone chrysops x M. Saxatilis)

Abstract Trans-4-Hydroxy-L-Proline (Hyp) is a major amino acid in the collagen of fish. The turnover of collagen in various tissues releases a large amount of Hyp, which has traditionally been considered as a metabolic waste. However, results of recent studies have identified the conversion of Hyp into glycine in piglets. The present study tests this hypothesis that hybrid striped bass (HSB, a carnivorous fish species) can form glycine from Hyp. Fish were fed a standard diet containing 60% fishmeal for 10 wk and grew from 5.5 to 45 g during a 9-wk period. Slices (~75 mg) of skeletal muscle, liver, proximal intestine, gills, and brain were obtained from 45-g HSB (n = 6) and incubated at 26 °C for 2 h in 1 mL of oxygenated (95% O2/5% CO2) Krebs-Henseleit bicarbonate buffer (pH 7.4, with 5 mM D-glucose) containing 0, 0.2, or 2 mM Hyp. After a period of 2 h incubation, 200 μL of 1.5 M HClO4 was added into the incubation medium to stop the reaction. The acidified medium plus tissue together was homogenized and the homogenizer was rinsed with 1 mL of water, followed by the addition of 100 μL of 2 M K2CO3. The neutralized extract was analyzed for amino acids using HPLC involving o-phthaldialdehyde derivatization. Tissues without incubation were also determined for amino acids. Data were statistically analyzed by a paired t-test. Glycine was produced from 0.2 and 2 mM Hyp by the liver and skeletal muscle, and 2 mM Hyp by the intestine (Table 1). Glycine was further converted into serine in the liver, but not skeletal muscle or intestine. The production of glycine or serine from Hyp was not due to net protein breakdown in tissues. Tyrosine was measured as an indicator of protein degradation. There was no detectable generation of glycine from 0.2 or 2 mM Hyp by the gills or brain of HSB. These results indicate the synthesis of glycine from Hyp by juvenile HSB in a tissue-specific manner. Because skeletal muscle accounts for ~45% of the body weight, this organ is the major site for this metabolic pathway in the fish. (Supported by USDA/NIFA grant No. 2022-67015-36200)

Unveiling the relationship of volatile compounds and microbial communities in light-struck taste rice wine: A comprehensive analysis

Light-struck taste rice wine (LST-RW) is the most popular new rice wine at present, which is brewed by a variety of microorganisms. However, the relationship between microorganisms and flavor substances in light-struck taste rice wine is still unexplored. In this study, high-throughput sequencing, high-performance liquid chromatography (HPLC), headspace solid-phase microextraction (HS-SPME), and gas chromatography–mass spectrometry (GC–MS) were used to prove that microbial community had significant influence on flavor substances during light-struck taste rice wine fermentation. The results indicated a consistent increase in the majority of amino acids and organic acids within LST-RW with extended fermentation duration. A total of 49 volatile flavor compounds, including alcohols, esters, and aldehydes, were identified. In the brewing process of LST-RW, Bacillus (17.13 %) and Saccharopolyspora (15.55 %) emerge as the predominant bacterial genera; Aspergillus (83.34 %) and Saccharomyces (15.21 %) emerged as the dominant fungal genera. A notable correlation was observed between fermentation microorganisms and flavor substances. Microorganism species exhibiting strong co-exclusion or symbiotic relationships were also identified. The research findings offer a theoretical reference for optimizing and innovating the fermentation process of LST-RW.

Chemical composition, functional properties, physico-chemical properties, and techno-functional characteristics of Satureja protein hydrolysate stabilized in a gelatin matrix.

The current evaluation was conducted to investigate the chemical composition and functional properties of protein hydrolysates from different Satureja species. The major amino acids (mg/100 g protein) in the protein from different Satureja species were arginine (6.06-14.37), asparagine (1.39-17.06), glutamine (2.42-11.60), glutamic acid (6.34-9.32), beta-aminoisobutyric acid (3.31-10.29), alanine (4.64-9.59), aspartic acid (5.73-9.54), proline (4.25-8.14), leucine (3.63-5.69), serine (2.64-4.83), lysine (1.89-4.56), glycine (0.96-5.27), valine (2.76-4.83), and phenylalanine (2.86-3.75). Protein hydrolysates from Satureja species exhibited comparable antioxidant activity (IC50 = 0.270-0.328 mg/mL), anti-linoleic acid oxidation (IC50 = 0.231-0.301 mg/mL), anti-lecithin oxidation (IC50 = 0.198-0.258 mg/mL), anti-starch oxidation (IC50 = 0.201-0.277 mg/mL), anti-amylase activity (IC50 = 0.314-0.337 mg/mL), and anti-lipase activity (IC50 = 0.309-0.369 mg/mL). The physico-chemical properties of gelatin dispersion were electrical conductivity (1197 microsiemens/cm), osmolarity (190 milliosmol/kg), surface tension (45 mN/m), particle size (179 nm), zeta potential (-48 mV), and viscosity (4.92 mPa.s). Techno-functional characteristics of freeze-dried gelatin particles were as follows: water content (7.68%), water solubility (84.57%), water swelling (151.33%), hygroscopicity (38.20%), hydrophobicity (6.50 μg/g), emulsification activity (68.54%), emulsification stability (57.86%), foam expansion activity (56.08%), foam stability (41.84%), oil-holding capacity (1.96 g/g), and water-holding capacity (4.45 g/g). Protein hydrolysate causes minor changes in the physico-chemical and techno-functional properties of gelatin. The current investigation introduces Satureja protein hydrolysate as a possible functional and techno-functional ingredient for bioactive food products for treating diabetes and oxidative stress and as a natural preservative for the food industry.

General instability of dipeptides in concentrated sulfuric acid as relevant for the Venus cloud habitability

Recent renewed interest in the possibility of life in the acidic clouds of Venus has led to new studies on organic chemistry in concentrated sulfuric acid. We have previously found that the majority of amino acids are stable in the range of Venus’ cloud sulfuric acid concentrations (81% and 98% w/w, the rest being water). The natural next question is whether dipeptides, as precursors to larger peptides and proteins, could be stable in this environment. We investigated the reactivity of the peptide bond using 20 homodipeptides and find that the majority of them undergo solvolysis within a few weeks, at both sulfuric acid concentrations. Notably, a few exceptions exist. HH and GG dipeptides are stable in 98% w/w sulfuric acid for at least 4 months, while II, LL, VV, PP, RR and KK resist hydrolysis in 81% w/w sulfuric acid for at least 5 weeks. Moreover, the breakdown process of the dipeptides studied in 98% w/w concentrated sulfuric acid is different from the standard acid-catalyzed hydrolysis that releases monomeric amino acids. Despite a few exceptions at a single concentration, no homodipeptides have demonstrated stability across both acid concentrations studied. This indicates that any hypothetical life on Venus would likely require a functional substitute for the peptide bond that can maintain stability throughout the range of sulfuric acid concentrations present.

Diagnosis of pregnancy disorder in the first-trimester patient plasma with Raman spectroscopy and protein analysis.

Gestational diabetes mellitus (GDM) is a pregnancy disorder associated with short- and long-term adverse outcomes in both mothers and infants. The current clinical test of blood glucose levels late in the second trimester is inadequate for early detection of GDM. Here we show the utility of Raman spectroscopy (RS) for rapid and highly sensitive maternal metabolome screening for GDM in the first trimester. Key metabolites, including phospholipids, carbohydrates, and major amino acids, were identified with RS and validated with mass spectrometry, enabling insights into associated metabolic pathway enrichment. Using classical machine learning (ML) approaches, we showed the performance of the RS metabolic model (cross-validation AUC 0.97) surpassed that achieved with patients' clinical data alone (cross-validation AUC 0.59) or prior studies with single biomarkers. Further, we analyzed novel proteins and identified fetuin-A as a promising candidate for early GDM prediction. A correlation analysis showed a moderate to strong correlation between multiple metabolites and proteins, suggesting a combined protein-metabolic analysis integrated with ML would enable a powerful screening platform for first trimester diagnosis. Our study underscores RS metabolic profiling as a cost-effective tool that can be integrated into the current clinical workflow for accurate risk stratification of GDM and to improve both maternal and neonatal outcomes.

Interactions Involving Glycine and Other Amino Acid Neurotransmitters: Focus on Transporter-Mediated Regulation of Release and Glycine-Glutamate Crosstalk.

Glycine plays a pivotal role in the Central Nervous System (CNS), being a major inhibitory neurotransmitter as well as a co-agonist of Glutamate at excitatory NMDA receptors. Interactions involving Glycine and other neurotransmitters are the subject of different studies. Functional interactions among neurotransmitters include the modulation of release through release-regulating receptors but also through transporter-mediated mechanisms. Many transporter-mediated interactions involve the amino acid transmitters Glycine, Glutamate, and GABA. Different studies published during the last two decades investigated a number of transporter-mediated interactions in depth involving amino acid transmitters at the nerve terminal level in different CNS areas, providing details of mechanisms involved and suggesting pathophysiological significances. Here, this evidence is reviewed also considering additional recent information available in the literature, with a special (but not exclusive) focus on glycinergic neurotransmission and Glycine-Glutamate interactions. Some possible pharmacological implications, although partly speculative, are also discussed. Dysregulations in glycinergic and glutamatergic transmission are involved in relevant CNS pathologies. Pharmacological interventions on glycinergic targets (including receptors and transporters) are under study to develop novel therapies against serious CNS pathological states including pain, schizophrenia, epilepsy, and neurodegenerative diseases. Although with limitations, it is hoped to possibly contribute to a better understanding of the complex interactions between glycine-mediated neurotransmission and other major amino acid transmitters, also in view of the current interest in potential drugs acting on "glycinergic" targets.

Radiolytic Effects on Biological and Abiotic Amino Acids in Shallow Subsurface Ices on Europa and Enceladus.

Europa and Enceladus are key targets to search for evidence of life in our solar system. However, the surface and shallow subsurface of both airless icy moons are constantly bombarded by ionizing radiation that could degrade chemical biosignatures. Therefore, sampling of icy surfaces in future life detection missions to Europa and Enceladus requires a clear understanding of the necessary ice depth where unaltered organic biomolecules might be present. We conducted radiolysis experiments by exposing individual amino acids in ices and amino acids from dead microorganisms in ices to gamma radiation to simulate conditions on these icy worlds. In the pure amino acid samples, glycine did not show a detectable decrease in abundance, whereas the abundance of isovaline decreased by 40% after 4 MGy of exposure. Amino acids in dead Escherichia coli (E. coli) organic matter exhibited a gradual decline in abundances with the increase of exposure dosage, although at much slower rates than individual amino acids. The majority of amino acids in dead A. woodii samples demonstrated a step function decline as opposed to a gradual decline. After the initial drop in abundance with 1 MGy of exposure, those amino acids did not display further decreases in abundance after exposure up to 4 MGy. New radiolysis constants for isolated amino acids and amino acids in dead E. coli material for Europa/Enceladus-like conditions have been derived. Slow rates of amino acid destruction in biological samples under Europa and Enceladus-like surface conditions bolster the case for future life detection measurements by Europa and Enceladus lander missions. Based on our measurements, the "safe" sampling depth on Europa is ∼20 cm at high latitudes of the trailing hemisphere in the area of little impact gardening. Subsurface sampling is not required for the detection of amino acids on Enceladus-these molecules will survive radiolysis at any location on the Enceladus surface. If the stability of amino acids observed in A. woodii organic materials is confirmed in other microorganisms, then the survival of amino acids from a potential biosphere in Europa ice would be significantly increased.

The Increased aspartate levels in transgenic cotton (Gossypium hirsutum L.) lead to improved tolerance against whitefly (Bemisia tabaci, Gennadius).

The whitefly, a polyphagous insect pest feeding on nearly 1328 plant species, is a major threat to global cotton production and incurs up to 50% yield losses in cotton production in Pakistan. We investigated whether increased aspartate in phloem sap imparts whitefly toxicity and protects cotton plants from intense damage. The enzymatic step for aspartate production is carried through aspartate aminotransferase (AAT). In this study, we constitutively overexpressed the Oryza sativa cytoplasmic AAT (OsAAT2) under the CaMV35S promoter in Gossypium hirsutum cv. CIM-482. Real-time PCR analysis of the AAT transcripts revealed a 2.85- to 31.7-fold increase in mRNA levels between the different cotton lines. A substantial increase in the free-amino acid content of the major N-assimilation and transport amino acids (aspartate, glutamate, asparagine, and glutamine) was seen in the phloem sap of the transgenic cotton lines. The bioassay revealed that the two transgenic cotton lines with the highest free aspartate content in the phloem sap exhibited 97 and 94% mortality in the adult whitefly population and a 98 and 96% decline in subsequent nymph populations, respectively. There was also a significant change in the physiological behaviour of the transgenic cotton lines, with an increased net assimilation (A), gaseous exchange (Gs) and rate of transpiration (E). Improved morphological characteristics like plant height, total number of bolls and fiber yield were recorded in transgenic cotton lines. The AAT gene shows promise in mitigating whitefly infestations and enhancing the overall health and yield of cotton plants.

Investigation of the quality of Lu'an Guapian tea during Grain Rain period by sensory evaluation, objective quantitative indexes and metabolomics

The harvest date is a crucial factor in determining tea quality. For Lu'an Guapian (LAGP) tea, Grain Rain period (GRP) represents a pivotal phase in the transformation of tea quality. The sensory evaluation, computer vision and E-tongue revealed that the liquor color score, B and G values of tea infusion were increased during GRP, while the astringency, bitterness intensities and the R value of the tea infusion were decreased. Consequently, the tea infusion exhibited a greener hue and the taste became appropriate during GRP. Non-targeted metabolomics revealed that the majority of amino acids and derivatives was reduced during GRP. Furthermore, flavonoids, in particular flavonol glycosides, exhibited considerable variation during GRP. Finally, nine metabolites were identified as markers for quality transformation during GRP by PLS and Random Forest. This study investigated the quality of LAGP teas during GRP and filled the gap in the variation of LAGP tea quality during GRP.

Auxins differentially affect growth in Scots pine and Norway spruce in spring and autumn

Trees adapt to changing environmental conditions largely by regulating growth processes, and ongoing climate aridization puts pressure on growth processes during spring and summer. However, trees can be limited in their ability to utilize favourable early-season and late-season conditions for growth, and many of these limitations can be due to shortages in auxin transport and/or signalling. We studied whether leaf spraying with auxins in spring and autumn can aid in the growth of Pinus sylvestris and Picea abies saplings. In spring, spruce demonstrated prominent positive effects of auxin supplementation on the growth of current-year shoot and xylem growth, with increased xylem cell formation, whereas a limited effect was observed in pine. Autumnal auxin treatment had prominent positive effects on the growth of the root system and xylem area in pine, activating xylem cell enlargement and increasing carbon deposition in cell walls. In spruce, the effects of auxin spraying on xylem growth were less prominent, and the effects on root growth were absent compared to those in pine. The metabolome analysis of pine organs demonstrated that the activation of growth processes in the xylem and roots was accompanied by a decrease in nonstructural carbohydrates in the cambial zone but an increase in roots, indicating that auxin influenced the link between growth and carbon balance in an organ-specific manner. The major amino acid content was not influenced by auxin treatment. The observed results indicate that changes in the auxin balance during the autumnal period can activate growth processes to increase plant adaptation to changing climate conditions.

Effect of biochar addition on the anaerobic digestion of food waste: microbial community structure and methanogenic pathways.

This study assessed the effects of the addition of biochar prepared at 700 °C with different dosages on the anaerobic digestion of food waste. The biochar addition at a concentration of 10.0 g/L increased the cumulative methane yield by 128%, and daily methane production was also significantly promoted. The addition of biochar derived from poplar sawdust significantly increased the relative abundance of dominant bacteria for anaerobic digestion by 85.54-2530% and promoted the degradation of refractory organic matter and the transfer of materials between the hydrolysis and acid production stages. Further analysis has demonstrated that Bathyarchaeia and hydrogenotrophic methanogens were enriched by the biochar addition. Meanwhile, the relative abundances of functional genes, including C5-branched dibasic acid metabolism, and pyruvate metabolism, were increased by 11.38-26.27%. The relative abundances of genes related to major amino acid metabolism, including histidine metabolism, lysine biosynthesis, and phenylalanine, tyrosine, and tryptophan biosynthesis, were increased by 11.96-15.71%. Furthermore, the relative abundances of genes involved in major replication and repair were increased by 14.76-22.76%, and the major folding, sorting, degradation, and translation were increased by 14.47-19.95%, respectively. The relative abundances of genes related to major membrane transport and cell motility were increased by 10.02 and 83.09%, respectively.

CsABCG11.2 mediates theanine uptake to alleviate cadmium toxicity in tea plants (Camellia sinensis)

Theanine (Thea) is a unique metabolite in tea plants, but its physiological functions remain elusive. A low soil pH increases cadmium (Cd) availability, affecting the quality of tea plant products. In this study, we found that Thea reversed the Cd-induced reduction in free amino acid (FAA) and caffeine (CAF) in the young tea leaves, as well as the down-regulation in the expression of nitrate transporters CsNRT1.2 and CsNRT2.5, and genes responsible for the nitrogen (N) assimilation. We demonstrated that Thea could alleviate Cd-induced oxidative stresses and enhance photosynthesis. Moreover, an ATP-binding cassette (ABC) transporter, CsABCG11.2, could uptake distinct Cd substrates and the five major amino acids in tea plants. Heterologous expression of CsABCG11.2 in yeast indicated a competitive absorption between Cd and Thea in a concentration-dependent pattern. CsABCG11.2-overexpressing Arabidopsis plants exhibited increased sensitivity to Cd due to enhanced Cd concentration, accumulation in the shoots, and reduction in the primary root length. Exogenous application of Thea at environmentally regular levels attenuated the adverse effects of Cd-induced growth inhibition and chlorosis in CsABCG11.2-overexpressing Arabidopsis plants. Knockdown of CsABCG11.2 tea plants significantly lowered Cd levels in young shoots. Our results suggest that Thea plays beneficial roles in alleviating Cd stress directly or indirectly by modulating CsABCG11.2-mediated Cd uptake and translocation within plants.

Study on adsorption behavior of humic acid on aluminum in Enteromorpha prolifera

High level of aluminum content in Enteromorpha prolifera posed a growing threat to both its growth and human health. This study focused on exploring the factors, impacts, and process of removing aluminum from Enteromorpha prolifera using humic acid. The results showed that under experimental conditions of 0.0330 g·L−1 humic acid concentration, pH 3.80, 34 °C, and a duration of 40 min, the removal rate was up to 80.18%. The levels of major flavor components, proteins, and amino acids in Enteromorpha prolifera increased significantly after treatment, while polysaccharides and trace elements like calcium and magnesium decreased significantly. Infrared spectroscopy demonstrated that the main functional groups involved in binding with Al3+ during humic acid adsorption were hydroxyl, carboxyl, phenol, and other oxygen-containing groups. The adsorption process of Al3+ by humic acid was a spontaneous phenomenon divided into three key stages: fast adsorption, slow adsorption, and adsorption equilibrium, which resulted from both physical and chemical adsorption effects. This study provided a safe and efficient method in algae metal removal.