Investigation of the biocontrol mechanism of a novel Pseudomonas species against phytopathogenic Fusarium graminearum revealed by multi-omics integration analysis.

Phytopathogenic Fusarium graminearum poses significant threats to crop health and soil quality. Although our laboratory-cultivated Pseudomonas sp. P13 exhibited potential biocontrol capacities, its effectiveness against F. graminearum and underlying antifungal mechanisms are still unclear. In light of this, our study investigated a significant inhibitory effect of P13 on F. graminearum T1, both in vitro and in a soil environment. Conducting genomic, metabolomic, and transcriptomic analyses of P13, we sought to identify evidence supporting its antagonistic effects on T1. The results revealed the potential of P13, a novel Pseudomonas species, to produce active antifungal components, including phenazine-1-carboxylate (PCA), hydrogen cyanide (HCN), and siderophores [pyoverdine (Pvd) and histicorrugatin (Hcs)], as well as the dynamic adaptive changes in the metabolic pathways of P13 related to these active ingredients. During the logarithmic growth stage, T1-exposed P13 strategically upregulated PCA and HCN biosynthesis, along with transient inhibition of the tricarboxylic acid (TCA) cycle. However, with growth stabilization, upregulation of PCA and HCN synthesis ceased, whereas the TCA cycle was enhanced, increasing siderophores secretion (Pvd and Hcs), suggesting that this mechanism might have caused continuous inhibition of T1. These findings improved our comprehension of the biocontrol mechanisms of P13 and provided the foundation for potential application of Pseudomonas strains in the biocontrol of phytopathogenic F. graminearum. IMPORTANCE: Pseudomonas spp. produces various antifungal substances, making it an effective natural biocontrol agent against pathogenic fungi. However, the inhibitory effects and the associated antagonistic mechanisms of Pseudomonas spp. against Fusarium spp. are unclear. Multi-omics integration analyses of the in vitro antifungal effects of novel Pseudomonas species, P13, against F. graminearum T1 revealed the ability of P13 to produce antifungal components (PCA, HCN, Pvd, and Hcs), strategically upregulate PCA and HCN biosynthesis during logarithmic growth phase, and enhance the TCA cycle during stationary growth phase. These findings improved our understanding of the biocontrol mechanisms of P13 and its potential application against pathogenic fungi.

Chemical defence of a centipede (Clinopodes flavidus).

Chemical substances are of utmost importance for the biotic interactions between animals and their predators/parasites; many of these semiochemicals are emitted for defence purposes. One of the most deterrent and toxic biogenic substances we know of is hydrogen cyanide, which can be stored by certain insects, millipedes, centipedes and arachnids in the form of stable and less volatile molecules. The aim of this study was to analyse the biology and chemistry of such a defence mechanism in a geophilomorph centipede (Chilopoda). The cyanogenic secretion of Clinopodes flavidus is discharged from the ventral glands, whose glandular units are located in the space between the cuticle and the trunk muscles and do not extend deep into the segment. In addition to hydrogen cyanide, the ventral secretion contains 2-methylpentanoic acid, benzaldehyde, benzoyl cyanide, 2-methyl branched C-9 carboxylic acid (tentatively identified as 2-methyloctanoic acid), methyl 2-phenylacetate, benzoic acid and mandelonitrile as well as four major proteins with a molecular weight of 150, 66.2, 59 and 55 kDa. The correlation between the presence of ventral glands and guarding with the female's ventral side facing away from the eggs and young indicates a functional link between these two traits. We hope that the specificity of the chemical composition of the ventral secretion could serve as a criterion for chemotaxonomy and that the analysis of more species will help to clarify the phylogenetic relationships within the Geophilomorpha.

Osmolyte-producing microbial biostimulants regulate the growth of Arachis hypogaea L. under drought stress.

Globally, drought stress poses a significant threat to crop productivity. Improving the drought tolerance of crops with microbial biostimulants is a sustainable strategy to meet a growing population's demands. This research aimed to elucidate microbial biostimulants' (Plant Growth Promoting Rhizobacteria) role in alleviating drought stress in oil-seed crops. In total, 15 bacterial isolates were selected for drought tolerance and screened for plant growth-promoting (PGP) attributes like phosphate solubilization and production of indole-3-acetic acid, siderophore, hydrogen cyanide, ammonia, and exopolysaccharide. This research describes two PGPR strains: Acinetobacter calcoaceticus AC06 and Bacillus amyloliquefaciens BA01. The present study demonstrated that these strains (AC06 and BA01) produced abundant osmolytes under osmotic stress, including proline (2.21 and 1.75 µg ml- 1), salicylic acid (18.59 and 14.21 µg ml- 1), trehalose (28.35 and 22.74 µg mg- 1 FW) and glycine betaine (11.35 and 7.74 mg g- 1) respectively. AC06 and BA01 strains were further evaluated for their multifunctional performance by inoculating in Arachis hypogaea L. (Groundnut) under mild and severe drought regimes (60 and 40% Field Capacity). Inoculation with microbial biostimulants displayed distinct osmotic-adjustment abilities of the groundnut, such as growth parameters, plant biomass, photosynthetic pigments, relative water content, proline, and soluble sugar in respective to control during drought. On the other hand, plant sensitivity indexes such as electrolyte leakage and malondialdehyde (MDA) contents were decreased as well as cooperatively conferred plant drought tolerance by induced alterations in stress indicators such as catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD). Thus, Acinetobacter sp. AC06 and Bacillus sp. BA01 can be considered as osmolyte producing microbial biostimulants to simultaneously induce osmotic tolerance and metabolic changes in groundnuts under drought stress.

Incidence and health risk assessment of hydrogen cyanide and multi-mycotoxins in Nigerian garri.

Garri is a granular, starchy food prepared by the fermentation of mashed cassava. Hydrogen cyanide (HCN) and mycotoxins are contaminants in certain foods at different points along the food value chain. The incidence and contamination levels of HCN and multi-mycotoxins in garri from five agroecological zones of Nigeria were determined using a spectrophotometric method and ultra-high-performance liquid chromatography-tandem mass spectroscopy (UHPLC-MS/MS), respectively. The health risk associated with the consumption of contaminated garri was assessed. The health risk assessment model was used to calculate the dietary exposure of humans to the mycotoxins in garri. This was done by estimating the daily intake (EDI), the percentage tolerable daily intake (%TDI), the annual hepatocellular carcinoma (HCC) cases attributable to exposure to aflatoxins (AFs) in garri, as well as the HCC risk. The average intake of garri was estimated at 0.303 kg/day for a Nigerian adult. The incidence of HCN was 98.3% (0.056-2.463 mg/kg), and fermentation reduced the HCN level in garri more than other processing steps. The twenty-one mycotoxins identified and quantified were all within maximum levels, as applicable to those that are regulated by the EU. The %TDI for the other mycotoxins, with the exception of AFs, showed no alarming health risk with garri consumption. Annual HCC cases resulting from AF in garri were estimated at 10-60 cases for HBsAg + ve individuals and 4-23 cases for HBsAg - ve individuals based on 8.1% hepatitis B virus (HBV) incidence. Results further revealed no interdependence between HCN levels and mycotoxin content. This work suggests an unlikely chance of acute toxicity from HCN and major mycotoxins from a garri-based diet in Nigeria. Hence, it is recommended that concerned regulatory bodies maintain the existing permissible limits for HCN in Garri.

Determination of the two-compartment model parameters of exhaled HCN by fast negative photoionization mass spectrometry.

Breath exhaled hydrogen cyanide (HCN) has been identified to be associated with several respiratory diseases. Accurately distinguishing the concentration and release rate of different HCN sources is of great value in clinical research. However, there are still significant challenges due to the high adsorption and low concentration characteristics of exhaled HCN. In this study, a two-compartment kinetic model method based on negative photoionization mass spectrometry was developed to simultaneously determine the kinetic parameters including concentrations and release rates in the airways and alveoli. The influences of the sampling line diameter, length, and temperature on the response time of the sampling system were studied and optimized, achieving a response time of 0.2 s. The negative influence of oral cavity-released HCN was reduced by employing a strategy based on anatomical lung volume calculation. The calibration for HCN in the dynamic range of 0.5-100 ppbv and limit of detection (LOD) at 0.3 ppbv were achieved. Subsequently, the experiments of smoking, short-term passive smoking, and intake of bitter almonds were performed to examine the influences of endogenous and exogenous factors on the dynamic parameters of the model method. The results indicate that compared with steady-state concentration measurements, the kinetic parameters obtained using this model method can accurately and significantly reflect the changes in different HCN sources, highlighting its potential for HCN-related disease research.

Harnessing the anti-cancer potential of linamarin: A computational study on design and hydrolysis mechanisms of its derivatives.

Cassava extracts containing cyanogenic compounds demonstrate anticancer properties. The cyanogenic glucoside linamarin found abundantly in cassava can release hydrogen cyanide (HCN) upon hydrolysis, a potent cytotoxin. However, linamarin's hydrolysis mechanism by human enzymes is poorly delineated and constitutes a bottleneck for therapeutic development. This study aimed to investigate linamarin's hydrolysis mechanism by human ß-glucosidase and identify structural derivatives with enhanced hydrolytic potential using density functional theory calculations. Results revealed α-anomeric derivatives as promising, with leaving group ability and steric bulk strongly governing hydrolysability. We identified several linamarin analogs with predicted rapid hydrolysis kinetics that may enable swift cytotoxic HCN release against cancer cells. This investigation enriches understanding of cyanogenic glycoside reactivity to facilitate their development as targeted antineoplastic agents. The identified derivatives set the groundwork for experimental evaluation of enhanced linamarin-inspired compounds as innovative cancer therapeutics.

Unveiling the effect of gibberellin-induced iron oxide nanoparticles on bud dormancy release in sweet cherry (Prunus avium L.).

Hydrogen cyanide has been extensively used worldwide for bud dormancy break in fruit trees, consequently enhancing fruit production via expedited cultivation, especially in areas with controlled environments or warmer regions. A novel and safety nanotechnology was developed since the hazard of hydrogen cyanide for the operators and environments, there is an urgent need for the development of novel and safety approaches to replace it to break bud dormancy for fruit trees. In current study, we have systematically explored the potential of iron oxide nanoparticles, specifically α-Fe2O3, to modulate bud dormancy in sweet cherry (Prunus avium). The synthesized iron oxide nanoparticles underwent meticulous characterization and assessment using various techniques, including Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and ultraviolet-visible infrared (UV-Vis) spectroscopy. Remarkably, when applied at a concentration of 10 mg L-1 alongside gibberellin (GA4+7), these iron oxide nanoparticles exhibited a substantial 57% enhancement in bud dormancy release compared to control groups, all achieved within a remarkably short time span of 4 days. Our RNA-seq analyses further unveiled that 2757 genes within the sweet cherry buds were significantly up-regulated when treated with 10 mg L-1 α-Fe2O3 nanoparticles in combination with GA, while 4748 genes related to dormancy regulation were downregulated in comparison to the control. Moreover, we discovered an array of 58 transcription factor families among the crucial differentially expressed genes (DEGs). Through hormonal quantification, we established that the increased bud burst was accompanied by a reduced concentration of abscisic acid (ABA) at 761.3 ng/g fresh weight in the iron oxide treatment group, coupled with higher levels of gibberellins (GAs) in comparison to the control. Comprehensive transcriptomic and metabolomic analyses unveiled significant alterations in hormone contents and gene expression during the bud dormancy-breaking process when α-Fe2O3 nanoparticles were combined with GA. In conclusion, our findings provide valuable insights into the intricate molecular mechanisms underlying the impact of iron oxide nanoparticles on achieving uniform bud dormancy break in sweet cherry trees.

High Reactivity of Supermolecular Nanoentities of a Vitamin B12 Derivative in Langmuir-Schaefer Films Toward Gaseous Toxins.

Recently, we have described the first supermolecular nanoentities (SMEs) of a vitamin B12 derivative, viz., a monocyano form of heptabutyl cobyrinate ((CN-)BuCby), unique nanoparticles with strong noncovalent intermolecular interactions, and emerging optical and redox properties. In this work, the fast response of thin films based on the SMEs of the B12 derivative to gaseous toxins (viz., hydrogen cyanide, ammonia, sulfur dioxide, and hydrogen sulfide) particularly dangerous for humans was demonstrated. The reaction between SMEs of (CN-)BuCby in Langmuir-Schaefer (LS) films and HCN generates dicyano species and proceeds ca. 5-fold more rapidly than the process involving drop-coated films that contain (CN-)BuCby in molecular form. The highest sensitivity toward HCN was achieved by using thicker LS films. The reaction proceeds reversibly: upon exposure to air, the dicyano complex undergoes partial decyanation. The decyanated complex retains reactivity toward HCN for at least four subsequent cycles. The processes involving SMEs of (CN-)BuCby and NH3, SO2, and H2S are irreversible, and the sensitivity of the films toward these gases is lower in comparison with HCN. Presented data provides mechanistic information on the reactions involving solid vitamin B12 derivatives and gaseous toxins. In the case of NH3, deprotonation of the coordinated Co(III)-ion water molecule occurs, and the generated hydroxocyano species exhibit high air stability. After binding of SO2, a mixture of sulfito and dicyano species is produced, and the regenerated film contains aquacyano and diaqua or aquahydroxo species, which possess high reactivity toward gaseous toxins. Reaction with H2S produces a mixture of the Co(III)-dicyano form and Co(II)-species containing sulfide oxidation products, which are resistant to aerobic oxidation. Our findings can be used for the development of naked-eye, electronic optic, and chemiresistive sensors toward gaseous toxins with improved reactivity for prompt cyanide detection in air, blood, and plant samples and for analysis of exhaled gases for the diagnosis of diseases.

Variable expression of cyanide detoxification and tolerance genes in cyanogenic and acyanogenic white clover (Trifolium repens).

PREMISE: ß-Cyanoalanine synthase (ß-CAS) and alternative oxidase (AOX) play important roles in the ability of plants to detoxify and tolerate hydrogen cyanide (HCN). These functions are critical for all plants because HCN is produced at low levels during basic metabolic processes, and especially for cyanogenic species, which release high levels of HCN following tissue damage. However, expression of ß-CAS and Aox genes has not been examined in cyanogenic species, nor compared between cyanogenic and acyanogenic genotypes within a species. METHODS: We used a natural polymorphism for cyanogenesis in white clover to examine ß-CAS and Aox gene expression in relation to cyanogenesis-associated HCN exposure. We identified all ß-CAS and Aox gene copies present in the genome, including members of the Aox1, Aox2a, and Aox2d subfamilies previously reported in legumes. Expression levels were compared between cyanogenic and acyanogenic genotypes and between damaged and undamaged leaf tissue. RESULTS: ß-CAS and Aox2a expression was differentially elevated in cyanogenic genotypes, and tissue damage was not required to induce this increased expression. Aox2d, in contrast, appeared to be upregulated as a generalized wounding response. CONCLUSIONS: These findings suggest a heightened constitutive role for HCN detoxification (via elevated ß-CAS expression) and HCN-toxicity mitigation (via elevated Aox2a expression) in plants that are capable of cyanogenesis. As such, freezing-induced cyanide autotoxicity is unlikely to be the primary selective factor in the evolution of climate-associated cyanogenesis clines.

Biological hydrogen cyanide emission globally impacts the physiology of both HCN-emitting and HCN-perceiving Pseudomonas.

IMPORTANCE: Bacteria communicate by exchanging chemical signals, some of which are volatile and can remotely reach other organisms. HCN was one of the first volatiles discovered to severely impact exposed organisms by inhibiting their respiration. Using HCN-deficient mutants in two Pseudomonas strains, we demonstrate that HCN's impact goes beyond the sole inhibition of respiration and affects both emitting and receiving bacteria in a global way, modulating their motility, biofilm formation, and production of antimicrobial compounds. Our data suggest that bacteria could use HCN not only to control their own cellular functions, but also to remotely influence the behavior of other bacteria sharing the same environment. Since HCN emission occurs in both clinically and environmentally relevant Pseudomonas, these findings are important to better understand or even modulate the expression of bacterial traits involved in both virulence of opportunistic pathogens and in biocontrol efficacy of plant-beneficial strains.

Old poisons, new signaling molecules: the case of hydrogen cyanide.

The high phenotypic plasticity developed by plants includes rapid responses and adaptations to aggressive or changing environments. To achieve this, they evolved extremely efficient mechanisms of signaling mediated by a wide range of molecules, including small signal molecules. Among them, hydrogen cyanide (HCN) has been largely ignored due to its toxic characteristics. However, not only is it present in living organisms, but it has been shown that it serves several functions in all kingdoms of life. Research using model plants has changed the traditional point of view, and it has been demonstrated that HCN plays a positive role in the plant response to pathogens independently of its toxicity. Indeed, HCN induces a response aimed at protecting the plant from pathogen attack, and the HCN is provided either exogenously (in vitro or by some cyanogenic bacteria species present in the rhizosphere) or endogenously (in reactions involving ethylene, camalexin, or other cyanide-containing compounds). The contribution of different mechanisms to HCN function, including a new post-translational modification of cysteines in proteins, namely S-cyanylation, is discussed here. This work opens up an expanding 'HCN field' of research related to plants and other organisms.

Thiophosphate photochemistry enables prebiotic access to sugars and terpenoid precursors.

Over the past few years, evidence has accrued that demonstrates that terrestrial photochemical reactions could have provided numerous (proto)biomolecules with implications for the origin of life. This chemistry simply relies on UV light, inorganic sulfur species and hydrogen cyanide. Recently, we reported that, under the same conditions, reduced phosphorus species, such as those delivered by meteorites, can be oxidized to orthophosphate, generating thiophosphate in the process. Here we describe an investigation of the properties of thiophosphate as well as additional possible means for its formation on primitive Earth. We show that several reported prebiotic reactions, including the photoreduction of thioamides, carbonyl groups and cyanohydrins, can be markedly improved, and that tetroses and pentoses can be accessed from hydrogen cyanide through a Kiliani-Fischer-type process without progressing to higher sugars. We also demonstrate that thiophosphate allows photochemical reductive aminations, and that thiophosphate chemistry allows a plausible prebiotic synthesis of the C5 moieties used in extant terpene and terpenoid biosynthesis, namely dimethylallyl alcohol and isopentenyl alcohol.

Static and Dynamical Quantum Studies of CX3-AlX2 and CSiX3-BX2 (X = F, Cl, Br) Complexes with Hydrocyanic Acid: Unusual Behavior of Strong π-Hole at Triel Center.

The set of TX3-TrX2 (T = C, Si, Ge; Tr = B, Al, Ga; X = F, Cl, Br) molecules offers a rather unique opportunity to study both σ-hole and π-hole dimerization on the tetrel and triel ends, respectively. According to the molecular electrostatic potential (MEP) distribution, the π-hole extrema (acidic sites) were more intense than their σ-hole counterparts. The molecules owning the most (CX3-AlX2) and least (SiX3-BX2) intense π-holes were chosen to evaluate their capacities to attract one and two HCN molecules (Lewis bases). We discovered that the energetic characteristics of π-hole dimers severely conflict with the monomers MEP pattern since the weakest π-hole monomer forms a dimer characterized by interaction energy compared to those created by the monomers with noticeably greater power in the π-hole region. This outcome is due to the deformation of the weakest π-hole donor. Furthermore, the MEP analysis for monomers in the geometry of respective dimers revealed a "residual π-hole" site that was able to drive second ligand attachment, giving rise to the two "unusual trimers" examined further by the NCI and QTAIM analyses. Apart from them, the π-hole/π-hole and σ-hole/π-hole trimers have also been obtained throughout this study and described using energetic and geometric parameters. The SAPT approach revealed details of the bonding in one of the "unusual trimers". Finally, Born-Oppenheimer Molecular Dynamics (BOMD) simulations were carried out to investigate the time evolution of the interatomic distances of the studied complexes as well as their stability.

Thermally Accessible Prebiotic Pathways for Forming Ribonucleic Acid and Protein Precursors from Aqueous Hydrogen Cyanide.

The search for prebiotic chemical pathways to biologically relevant molecules is a long-standing puzzle that has generated a menagerie of competing hypotheses with limited experimental prospects for falsification. However, the advent of computational network exploration methodologies has created the opportunity to compare the kinetic plausibility of various channels and even propose new pathways. Here, the space of organic molecules that can be formed within four polar or pericyclic reactions from water and hydrogen cyanide (HCN), two established prebiotic candidates for generating biological precursors, was comprehensively explored with a state-of-the-art exploration algorithm. A surprisingly diverse reactivity landscape was revealed within just a few steps of these simple molecules. Reaction pathways to several biologically relevant molecules were discovered involving lower activation energies and fewer reaction steps compared with recently proposed alternatives. Accounting for water-catalyzed reactions qualitatively affects the interpretation of the network kinetics. The case-study also highlights omissions of simpler and lower barrier reaction pathways to certain products by other algorithms that qualitatively affect the interpretation of HCN reactivity.

Cross-species activation of hydrogen cyanide production by a promiscuous quorum-sensing receptor promotes Chromobacterium subtsugae competition in a dual-species model.

Many saprophytic bacteria have LuxR-I-type acyl-homoserine lactone (AHL) quorum-sensing systems that may be important for competing with other bacteria in complex soil communities. LuxR AHL receptors specifically interact with cognate AHLs to cause changes in expression of target genes. Some LuxR-type AHL receptors have relaxed specificity and are responsive to non-cognate AHLs. These promiscuous receptors might be used to sense and respond to AHLs produced by other bacteria by eavesdropping. We are interested in understanding the role of eavesdropping during interspecies competition. The soil saprophyte Chromobacterium subtsugae has a single AHL circuit, CviR-I, which produces and responds to N-hexanoyl-HSL (C6-HSL). The AHL receptor CviR can respond to a variety of AHLs in addition to C6-HSL. In prior studies we have utilized a coculture model with C. subtsugae and another soil saprophyte, Burkholderia thailandensis. Using this model, we previously showed that promiscuous activation of CviR by B. thailandensis AHLs provides a competitive advantage to C. subtsugae. Here, we show that B. thailandensis AHLs activate transcription of dozens of genes in C. subtsugae, including the hcnABC genes coding for production of hydrogen cyanide. We show that hydrogen cyanide production is population density-dependent and demonstrate that the cross-induction of hydrogen cyanide by B. thailandensis AHLs provides a competitive advantage to C. subtsugae. Our results provide new information on C. subtsugae quorum sensing and are the basis for future studies aimed at understanding the role of eavesdropping in interspecies competition.

Mechanism, Kinetics and Thermodynamics of Decomposition for High Energy Derivatives of [1,2,4]Triazolo[4,3-b][1,2,4,5]tetrazine.

This paper presents the data of research studies on the mechanisms, kinetics and thermodynamics of decomposition of three high-energy compounds: [1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine-3,6-diamine (TTDA), 3-amino-6-hydrazino[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine (TTGA) and 3,6-dinitroamino[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine (DNTT). The points of change of the reaction mechanisms under thermal effects with different intensities from 0.1 to 2000 s-1 have been established. The values of activation and induction energies for the limiting stages of decomposition have been obtained. The formation of nanostructured carbon nitride (α-C3N4) in condensed decomposition products, cyanogen (C2N2) and hydrogen cyanide (HCN) in gaseous products have been shown. Concentration-energy diagrams for the reaction products have been compiled. The parameters of heat resistance and thermal safety proved to be: 349.5 °C and 358.2 °C for TTDA; 190.3 °C and 198.0 °C for TTGA; 113.4 °C and 114.1 °C for DNTT. The energy and thermodynamic properties have also been estimated. This work found the activation energy of the decomposition process to be 129.0 kJ/mol for TTDA, 212.2 kJ/mol for TTGA and 292.2 kJ/mol for DNTT. The average induction energy of the catalytic process (Ecat) for TTGA was established to be 21 kJ/mol, and for DNTT-1500-1700 kJ/mol. The induction energy of the inhibition process (Eing) of TTDA was estimated to be 800-1400 kJ/mol.

Amygdalin: A Review on Its Characteristics, Antioxidant Potential, Gastrointestinal Microbiota Intervention, Anticancer Therapeutic and Mechanisms, Toxicity, and Encapsulation.

Bioactive amygdalin, found in high concentrations in bitter almonds, has been recognized as a symbol of the cyanogenic glycoside chemical organic substance, which was initially developed as a pharmaceutical for treating cancer after being hydrolyzed to hydrogen cyanide (HCN). Regrettably, research has shown that HCN can also damage normal cells, rendering it non-toxic to the human body. Extreme controversy surrounds both in vivo and in vitro studies, making its use risky. This review provides an extensive update on characteristics, antioxidant potential, gastrointestinal microbiota intervention, anticancer therapeutic, mechanisms, toxicity, and encapsulation of amygdalin. Antioxidant, anti-tumor, anti-fibrotic, antiatherosclerosis, anti-inflammatory, immunomodulatory, and analgesic characteristics, and the ability to improve digestive and reproductive systems, neurodegeneration, and cardiac hypertrophy are just some of the benefits of amygdalin. Studies verified the HCN-produced amygdalin to be harmful orally, but only at very high doses. Although intravenous treatment was less effective than the oral method, the oral route has a dose range of 0.6 to 1 g daily. Amygdalin's toxicity depends heavily on the variety of bacteria in the digestive tract. Unfortunately, there is currently no foolproof method for determining the microbial consortium and providing a safe oral dosage for every patient. Amygdalin encapsulation in alginate-chitosan nanoparticles (ACNPs) is a relatively new area of research. Amygdalin has an enhanced cytotoxic effect on malignant cells, and ACNPs can be employed as an active drug-delivery system to release this compound in a regulated, sustained manner without causing any harm to healthy cells or tissues. In conclusion, a large area of research for a substance that might be the next step in cancer therapy is opened up due to unverified and conflicting data.

Fine mapping of a major QTL qPA7-1 for low hydrocyanic acid content in sorghum-sudangrass hybrid.

The purpose of this study was to study the genetic mechanism of low hydrocyanic acid (HCN) content. The segregation of HCN content trait in fresh stems and leaves was determined in the sorghum (Sorghum bicolor (L.) Moench)-sudangrass (Sorghum sudanense (Piper) Stapf) hybrid F2 population (N = 1200), also used to detect a quantitative trait locus (QTL) for HCN content. Our hypothesis was that the additive effect of QTL was negative, showing that QTL was associated with low HCN. In the present research, a total of 11 simple sequence repeats (SSR) polymorphic primers were screened, and four SSR markers associated with low HCN content were developed based on the bulked segregant analysis method. A high-resolution genetic linkage group of the previously known qPA7-1 locus of the low HCN trait was constructed by analyzing different populations, families, and recombinants. Then, the QTL qPA7-1 of sorghum-sudangrass hybrid was fine-mapped to a 203.6 kb region between markers SORBI4G4-120 and SORBI4G4-680, and seven candidate genes for low HCN were predicted in this region based on sequence comparison with the sorghum reference genome. According to gene annotation, the candidate genes related to low HCN content may be different from those involved in the known regulation mode of sorghum dhurrin biosynthesis and metabolism.

Plant Growth-Promoting Rhizobacteria Promote Growth of Seedlings, Regulate Soil Microbial Community, and Alleviate Damping-Off Disease Caused by Rhizoctonia solani on Pinus sylvestris var. mongolica.

As the excessive use of chemical fertilizers harms organisms and adversely affects the soil environment, the replacement of chemical fertilizers with biological fertilizers has attracted widespread attention as an environmental protection strategy. In this study, the effects of rhizosphere bacteria inoculation on growth of Pinus sylvestris var. mongolica seedlings, soil parameters, soil microbial community structure, and the biocontrol of damping-off were studied by pot experiments. The results showed that all three rhizosphere bacteria (Pseudomonas chlororaphis, Pseudomonas extremaustralis, and Acinetobacter lwoffii A07) tested exhibited growth-promoting properties, such as the production of indole-3-acetic acid, hydrolase, siderophores, and hydrogen cyanide; nitrogen fixation; and phosphorus solubilization. The application of the three bacteria increased plant biomass, root structure, and nutrient content and also increased soil nutrient content and enzyme activity. Bacterial inoculation promoted the growth of beneficial bacteria and antagonistic bacteria by adjusting the physicochemical properties of the soil, thereby improving the bacterial community structure. Among the soil features, available nitrogen, total nitrogen, available potassium, and urease activity were the main influencing factors. In addition, it was also found that bacterial inoculation significantly increased the activities of plant superoxide dismutase, catalase, peroxidase, and other defense enzymes; enhanced plant disease resistance; effectively inhibited damping-off; and promoted plant growth. In summary, the application of three rhizosphere bacteria systematically affected the interaction between plants, soil parameters, and soil microbial communities. These results provide a basis for understanding how rhizosphere bacteria promote the growth of P. sylvestris var. mongolica, thereby offering a promising sustainable alternative to chemical fertilizers.

Pseudomonas aeruginosa Production of Hydrogen Cyanide Leads to Airborne Control of Staphylococcus aureus Growth in Biofilm and In Vivo Lung Environments.

Diverse bacterial volatile compounds alter bacterial stress responses and physiology, but their contribution to population dynamics in polymicrobial communities is not well known. In this study, we showed that airborne volatile hydrogen cyanide (HCN) produced by a wide range of Pseudomonas aeruginosa clinical strains leads to at-a-distance in vitro inhibition of the growth of a wide array of Staphylococcus aureus strains. We determined that low-oxygen environments not only enhance P. aeruginosa HCN production but also increase S. aureus sensitivity to HCN, which impacts P. aeruginosa-S. aureus competition in microaerobic in vitro mixed biofilms as well as in an in vitro cystic fibrosis lung sputum medium. Consistently, we demonstrated that production of HCN by P. aeruginosa controls S. aureus growth in a mouse model of airways coinfected by P. aeruginosa and S. aureus. Our study therefore demonstrates that P. aeruginosa HCN contributes to local and distant airborne competition against S. aureus and potentially other HCN-sensitive bacteria in contexts relevant to cystic fibrosis and other polymicrobial infectious diseases. IMPORTANCE Airborne volatile compounds produced by bacteria are often only considered attractive or repulsive scents, but they also directly contribute to bacterial physiology. Here, we showed that volatile hydrogen cyanide (HCN) released by a wide range of Pseudomonas aeruginosa strains controls Staphylococcus aureus growth in low-oxygen in vitro biofilms or aggregates and in vivo lung environments. These results are of pathophysiological relevance, since lungs of cystic fibrosis patients are known to present microaerobic areas and to be commonly associated with the presence of S. aureus and P. aeruginosa in polymicrobial communities. Our study therefore provides insights into how a bacterial volatile compound can contribute to the exclusion of S. aureus and other HCN-sensitive competitors from P. aeruginosa ecological niches. It opens new perspectives for the management or monitoring of P. aeruginosa infections in lower-lung airway infections and other polymicrobial disease contexts.