Overexpression of phosphatidylserine synthase IbPSS1 enhances salt tolerance by stimulating ethylene signaling-dependent lignin synthesis in sweetpotato roots.

Phosphatidylserine (PS) is an important lipid signaling required for plant growth regulation and salt stress adaptation. However, how PS positively regulate plant salt tolerance is still largely unknown. In this study, IbPSS1-overexpressed sweetpotato plants that exhibited overproduction of PS was employed to explore the mechanisms underlying the PS stimulation of plant salt tolerance. The results revealed that the IbPSS1-overexpressed sweetpotato accumulated less Na+ in the stem and leaf tissues compared with the wild type plants. Proteomic profile of roots showed that lignin synthesis-related proteins over-accumulated in IbPSS1-overexpressed sweetpotato. Correspondingly, the lignin content was enhanced but the influx of Na + into the stele was significantly blocked in IbPSS1-overexpressed sweetpotato. The results further revealed that ethylene synthesis and signaling related genes were upregulated in IbPSS1-overexpressed sweetpotato. Ethylene imaging experiment revealed the enhancement of ethylene mainly localized in the root stele. Inhibition of ethylene synthesis completely reversed the PS-overproduction induced lignin synthesis and Na+ influx pattern in stele tissues. Taken together, our findings demonstrate a mechanism by which PS regulates ethylene signaling and lignin synthesis in the root stele, thus helping sweetpotato plants to block the loading of Na+ into the xylem and to minimize the accumulation of Na+ in the shoots.

Genome-Wide Identification and Expression Analysis of the DMP and MTL Genes in Sweetpotato (Ipomoea batatas L.).

Sweetpotato (Ipomoea batatas L.) is a strategic crop with both economic and energy value. However, improving sweetpotato varieties through traditional breeding approaches can be a time-consuming and labor-intensive process due to the complex genetic nature of sweetpotato as a hexaploid species (2n = 6x = 90). Double haploid (DH) breeding, based on in vivo haploid induction, provides a new approach for rapid breeding of crops. The success of haploid induction can be achieved by manipulating specific genes. Two of the most critical genes, DMP (DUF679 membrane proteins) and MTL (MATRILINEAL), have been shown to induce haploid production in several species. Here, we identified and characterized DMP and MTL genes in sweetpotato using gene family analysis. In this study, we identified 5 IbDMPs and 25 IbpPLAs. IbDMP5 and IbPLAIIs (IbPLAIIκ, IbPLAIIλ, and IbPLAIIµ) were identified as potential haploid induction (HI) genes in sweetpotato. These results provide valuable information for the identification and potential function of HI genes in sweetpotato and provide ideas for the breeding of DH lines.

Characterization of the follicular fluid microbiota based on culturomics and sequencing analysis.

Introduction. The human oocyte microenvironment is follicular fluid, which is important for follicle growth, ovulation and maturation of the oocyte. The micro-organisms present in follicular fluid could be a predictor of in vitro fertilization outcomes.Hypothesis/Gap Statement. Women with follicular fluid colonized with micro-organisms can be asymptomatic, but the presence of some genera in the follicular fluid correlates with in vitro fertilization.Aim. To confirm the existence of micro-organisms in follicular fluid, and to profile the micro-organisms present in follicular fluid sampled from women undergoing in vitro fertilization with different outcomes.Methodology. Women undergoing in vitro fertilization (n=163) were divided into different subgroups according to their in vitro fertilization outcomes. Their follicular fluid samples were collected, and among them, 157 samples were analysed by 16S rDNA sequencing, and 19 samples were analysed using culturomics.Results. The culturomics results suggested that the 19 follicular fluid samples were not sterile. The isolation rates for Streptococcus, Finegoldia and Peptoniphilus were >50 % in the 19 samples. Linear discriminant analysis effect size analysis showed differential bacteria abundance according to the pregnancy rate, the rate of normal fertilization, the rate of high-quality embryos and the rate of available oocytes. The sequencing results showed that micro-organisms could be detected in all 157 samples. Pseudomonas, Lactobacillus, Comamonas, Streptococcus and Acinetobacter were detected in all of the samples, but with a wide range of relative abundance. Pseudomonas, Lactobacillus, Ralstonia and Vibrio constituted a notable fraction of the microbiota.Conclusions. Follicular fluid is not sterile. Micro-organisms in follicular fluid could be a predictor of in vitro fertilization outcomes.

Amelioration of intestinal barrier function and reduction of blood lead level in adult women with recurrent spontaneous abortion by a novel product of dietary fiber mixture, Holofood.

BACKGROUND: The elevated circulating toxins secondary to the impairment of intestinal barrier integrity commonly elicit a chronic inflammatory response and finally contribute to multiple diseases. These toxins, including bacterial by-products and heavy metals, are the potent risk factors for the development of recurrent spontaneous abortion (RSA). Preclinical evidence suggests that several dietary fibers can restore intestinal barrier function and decrease the accumulation of heavy metals. However, it is uncertain whether treatment with a newly developed blend of dietary fibers product (Holofood) benefits patients with RSA. METHODS: In this trial, we enrolled 70 adult women with RSA, who were randomly assigned into the experiment group and the control group in a 2:1 ratio. Upon the basis of conventional therapy, subjects in the experiment group (n = 48) received 8 weeks oral administration with Holofood three times daily at a dose of 10 g each time. Subjects without Holofood consumption were set as the control (n = 22). Blood samples were collected for the determinations of metabolic parameters, heavy mental lead, and the indices related to intestinal barrier integrity (D-lactate, bacterial endotoxin, and diamine oxidase activity). RESULTS: The reduction amplitude in blood lead from baseline to week 8 was 40.50 ± 54.28 (µg/L) in the experiment group as compared with 13.35 ± 36.81 (µg/L) in the control group (P = 0.037). The decreased level of serum D-lactate from baseline to week 8 was 5.58 ± 6.09 (mg/L) in the experiment group as compared with - 2.38 ± 8.90 (mg/L, P < 0.0001) in the control group. The change in serum DAO activity from baseline to week 8 was 3.26 ± 2.23 (U/L) in the experiment group as compared with - 1.24 ± 2.22 (U/L, P < 0.0001) in the control group. Participants who received Holofood had a greater decline in blood endotoxin from baseline to week 8 than those in the control group. Moreover, by comparing with the self-baseline, Holofood consumption significantly decreased the blood levels of lead, D-lactate, bacterial endotoxin, and DAO activity. CONCLUSION: Our results suggest that Holofood affords a clinically relevant improvements in blood lead level and intestinal barrier dysfunction in patients with RSA.

Curtanaerobium respiraculi gen. nov., sp. nov., a novel anaerobic bacterium isolated from human bronchoalveolar lavage fluid.

Two related anaerobic strains, designated as SWB101512T and SWB19611, were isolated from the bronchoalveolar lavage fluid of two lung cancer patients. Cells were Gram-stain-positive, non-motile and non-spore-forming. Growth could be observed at 26-45 °C (optimum, 37 °C), pH 5.0-8.5 (optimum, pH 7.0) and with 0.5-2.0 % (v/w) NaCl (optimum, 1.0%). The 16S rRNA gene sequences of SWB101512T and SWB19611 showed the highest similarities to Denitrobacterium detoxificans DSM 21843T (91.1 and 91.3 %, respectively). The phylogenetic tree based on the 16S rRNA gene sequences and the core genome sequences demonstrated that the two strains clustered together and formed a distinct lineage within the family Eggerthellaceae. The DNA G+C contents of strains SWB101512T and SWB19611 were 62.0 and 61.9 mol%, respectively. The predominant cellular fatty acids of strains SWB101512T and SWB19611 were C16 : 0 DMA (27.8 and 28.8 %, respectively). The respiratory menaquinone in both strains was menaquinone 6 and the polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, two phospholipids, three glycolipids and three unidentified lipids. Based on evidence from phenotypic, chemotaxonomic and genomic analyses, a new genus and species belonging to the family Eggerthellaceae, named Curtanaerobium respiraculi gen. nov., sp. nov. is proposed. The type strain is SWB101512T (=GDMCC 1.2991T=JCM 35330T).

More flexible and more innovative: the impact of flexible work arrangements on the innovation behavior of knowledge employees.

Flexible work arrangements (FWA) are becoming increasingly widespread as an efficient means of coping with a dynamic and competitive business environment. Existing studies have primarily examined the impact of FWA as a management system; however, its impact on employee innovation behavior has not been fully explored. Based on the self-determination theory, this study constructed a moderated mediation model that empirically examined the influence of FWA on the innovation behavior of knowledge employees. Our findings are as follows: (1) FWA can activate innovation behavior among knowledge employees; (2) thriving at work plays a partial mediating role; (3) human resource policies that facilitate opportunities have a positive moderating effect. The findings fill a theoretical research gap and provide insights for managers on implementing FWA to promote the innovative behavior of knowledge employees.

Role of Soil and Foliar-Applied Carbon Dots in Plant Iron Biofortification and Cadmium Mitigation by Triggering Opposite Iron Signaling in Roots.

In China, iron (Fe) availability is low in most soils but cadmium (Cd) generally exceeds regulatory soil pollution limits. Thus, biofortification of Fe along with mitigation of Cd in edible plant parts is important for human nutrition and health. Carbon dots (CDs) are considered as potential nanomaterials for agricultural applications. Here, Salvia miltiorrhiza-derived CDs are an efficient modulator of Fe, manganese (Mn), zinc (Zn), and Cd accumulation in plants. CDs irrigation (1 mg mL-1 , performed every week starting at the jointing stage for 12 weeks) increased Fe content by 18% but mitigated Cd accumulation by 20% in wheat grains. This finding was associated with the Fe3+ -mobilizing properties of CDs from the soil and root cell wall, as well as endocytosis-dependent internalization in roots. The resulting excess Fe signaling mitigated Cd uptake via inhibiting TaNRAMP5 expression. Foliar spraying of CDs enhanced Fe (44%), Mn (30%), and Zn (19%) content with an unchanged Cd accumulation in wheat grains. This result is attributed to CDs-enhanced light signaling, which triggered shoot-to-root Fe deficiency response. This study not only reveals the molecular mechanism underlying CDs modulation of Fe signaling in plants but also provides useful strategies for concurrent Fe biofortification and Cd mitigation in plant-based foods.

Characterization of Lung and Oral Microbiomes in Lung Cancer Patients Using Culturomics and 16S rRNA Gene Sequencing.

Recently, microbiota dysbiosis in lung cancer has attracted immense attention. Studies on lung microbes are mostly based on sequencing, which has left the potentially functional bacteria with extremely low abundance uncovered. In this study, we characterized and compared the lung and oral cavity microbiotas using culturomics and 16S rRNA gene sequencing. Of the 198 bacteria identified at the species level from bronchoalveolar lavage fluid (BALF) samples, Firmicutes was predominant (39.90%). Twenty bacterial species isolated from BALF samples were present in at least half of the patients and were also highly abundant in oral samples. Of all isolated strains, Streptococcus and Veillonella were highly dominant. The abundance of Prevotella and Veillonella decreased from the oral cavity to the lung, whereas that of Pseudomonas increased. Linear discriminant analysis effect size demonstrated that Prevotella was more abundant in the healthy samples than in the cancerous ones, which is in accordance with the isolation of Prevotella oralis only from the healthy group using culturomics. Moreover, Gemella sanguinis and Streptococcus intermedius were isolated only from the non-small-cell lung cancer (NSCLC) group, and 16S rRNA gene sequencing showed that they were higher in the NSCLC than in the small-cell lung cancer group. Furthermore, while Bacillus and Castellaniella were enriched in lung adenocarcinoma, Brucella was enriched in lung squamous cell carcinoma. Overall, alterations were observed in the microbial community of patients with lung cancer, whose diversity might be site and pathology dependent. Using culturomics and 16S rRNA gene amplicon sequencing, this study has provided insights into pulmonary and oral microbiota alterations in patients with lung cancer. IMPORTANCE The relationship between lung microbiota and cancer has been explored based on DNA sequencing; however, culture-dependent approaches are indispensable for further studies on the lung microbiota. In this study, we applied a comprehensive approach combining culturomics and 16S rRNA gene amplicon sequencing to detect members of the microbiotas in saliva and BALF samples from patients with unilateral lobar masses. We found alterations in the microbial community of patients with lung cancer, whose diversity might be site and pathology dependent. These features may be potential bacterial biomarkers and new targets for lung cancer diagnosis and treatment. In addition, a lung and oral microbial biobank from lung cancer patients was established, which represents a useful resource for studies of host-microbe interactions.

Aryl hydrocarbon receptor nuclear translocator limits the recruitment and function of regulatory neutrophils against colorectal cancer by regulating the gut microbiota.

BACKGROUND: Although the role and mechanism of neutrophils in tumors have been widely studied, the precise effects of aryl hydrocarbon receptor nuclear translocator (ARNT) on neutrophils remain unclear. In this study, we investigated the roles of ARNT in the function of CD11b+Gr1+ neutrophils in colitis-associated colorectal cancer. METHODS: Wild-type (WT), ARNT myeloid-specific deficient mice and a colitis-associated colorectal cancer mouse model were used in this study. The level and functions of CD11b+Gr1+ cells were evaluated by flow cytometry and confocal microscopy. RESULTS: We found that ARNT deficiency drives neutrophils recruitment, neutrophil extracellular trap (NET) development, inflammatory cytokine secretion and suppressive activities when cells enter the periphery from bone marrow upon colorectal tumorigenesis. ARNT deficiency displays similar effects to aryl hydrocarbon receptor (AHR) deficiency in neutrophils. CXCR2 is required for NET development, cytokine production and recruitment of neutrophils but not the suppressive activities induced by Arnt-/- in colorectal cancer. The gut microbiota is essential for functional alterations in Arnt-/- neutrophils to promote colorectal cancer growth. The colorectal cancer effects of Arnt-/- neutrophils were significantly restored by mouse cohousing or antibiotic treatment. Intragastric administration of the feces of Arnt-/- mice phenocopied their colorectal cancer effects. CONCLUSION: Our results defined a new role for the transcription factor ARNT in regulating neutrophils recruitment and function and the gut microbiota with implications for the future combination of gut microbiota and immunotherapy approaches in colorectal cancer.

Safety Evaluation and Probiotic Potency Screening of Akkermansia muciniphila Strains Isolated from Human Feces and Breast Milk.

Akkermansia muciniphila is considered a next-generation probiotic because of its immense potential to regulate disorders. We isolated 31 strains of A. muciniphila from feces or breast milk of healthy people. After genome sequencing, assembly, and analysis, we selected six strains (AM01 to AM06) for further exploration. We first analyzed their general characteristics, including morphological description, growth characteristics, and physiological and biochemical characteristics, and then confirmed their genetic characteristics, including GC content, putative virulence factors, and antibiotic resistance genes. We next investigated the tolerance of these strains to artificial gastric and intestinal fluids and bile salts to evaluate their survival potential in the digestive tract. Drug sensitivity tests were also conducted based on the analysis of the antibiotic resistance genes of these strains. Furthermore, we examined the genetic stability and acute toxicity of two strains (AM02 and AM06) in mice. Finally, the safety of AM06 was evaluated in normal mice and nude mice. AM06 exhibited adaptability to pH changes. Since AM02 and AM03 showed more resistance to antibiotics than AM01 and AM04 to AM06, their potential clinical application may be limited. Both AM02 and AM06 were genetically and phenotypically stable and safe in normal mice, and AM06 was safe in nude mice. Considering all this together, AM06 is a safe A. muciniphila strain and exhibits a great potential for use as a probiotic strain among the isolated strains. IMPORTANCE In this study, we isolated 30 strains of Akkermansia muciniphila from different samples of human feces, and for the first time we isolated an A. muciniphila strain from human breast milk. This isolation verified the existence of microbes in human breast milk, which suggests that A. muciniphila can be vertically propagated from mother to infant and participates in the formation of the early gut microbiome. We then systematically evaluated the potential for use as a probiotic of this A. muciniphila strains according to the FAO/WHO recommendation. We confirmed that the AM06 strain isolated from breast milk has no virulence factors and is genetically stable and nonpathogenic for both normal mice and nude mice. Moreover, its tolerance to pH changes and bile salts indicates its desirable probiotic properties. Thus, we propose that the AM06 strain of A. muciniphila is safe for use as a probiotic candidate.

Parvimonas micra activates the Ras/ERK/c-Fos pathway by upregulating miR-218-5p to promote colorectal cancer progression.

BACKGROUND: Colorectal cancer (CRC) is the third most common cancer in the world, and a strong relationship exists between CRC and gut microbiota, which affects the occurrence, development, and metastasis of cancer. Bioinformatics-based analyses revealed that the abundance of Parvimonas micra (P. micra) in the feces of patients with cancer is significantly higher than that in healthy people. Therefore, an important relationship may exist between P. micra and CRC. METHODS: We first confirmed that P. micra can promote the proliferation of cell lines through cell experiments and mouse models. Then we selected the signaling pathways and content of exosomes to promote the development of CRC by transcriptomics and microRNA sequencing. Finally, we confirmed that P. micra promoted CRC development through miR-218-5p/Ras/ERK/c-Fos pathway through the in vivo and in vitro experiments. RESULTS: First, it was confirmed by in vitro and in vivo experiments that P. micra can promote the development of CRC. Transcriptome analysis after the coincubation of bacteria and cells revealed that P. micra promoted cell proliferation by activating the Ras/ERK/c-Fos pathway. Furthermore, microRNA sequencing analysis of the cells and exosomes showed that miR-218-5p and protein tyrosine phosphatase receptor R (PTPRR) were the key factors involved in activating the Ras/ERK/c-Fos pathway, and the miR-218-5p inhibitor was used to confirm the role of microRNA in xenograft mice. CONCLUSION: This experiment confirmed that P. micra promoted the development of CRC by upregulating miR-218-5p expression in cells and exosomes, inhibiting PTPRR expression, and ultimately activating the Ras/ERK/c-Fos signaling pathway.

A recognition strategy combining effective boron affinity technology and surface imprinting to prepare highly selective and easily recyclable polymer membrane for separation of drug molecule.

Cellulose acetate membrane (CAM) has become one of the most widely used membrane materials by virtue of stability and hydrophilicity. In this work, to achieve the aim of selective recognition and separation of drug molecule shikimic acid (SA), an effective recognition tactics was proposed by combining boron affinity technology with surface imprinting strategy based on cellulose acetate membrane with low price and biocompatibility. The supporting CAM material was prepared through the phase inversion technique by continuous adjustment of different factors including solvent type and kinds of pore-forming agents, and the optimal CAM with multistage structure and highly porosity was applied for the imprinting of SA. Then the imprinted polymer membrane (MIPs-CAM) was developed via boron affinity surface imprinting polymerization. Various methods (FT-IR, UV-vis, SEM, XPS, AFM and TGA) were used to characterize the structure, morphology, elemental composition, surface roughness and thermal property of the obtained membrane. The as-prepared MIPs-CAM showed homogeneous and abundant imprinted layer, good thermal stability. The batch adsorption results showed that the MIPs-CAM had fast adsorption kinetics, specific recognition ability, and the adsorption capacity could obtain 63.598 mg g-1, which was two times higher than that of non-imprinted membrane (NIPs-CAM). The adsorption isotherms conformed to the Langmuir isotherm and the adsorption processes were spontaneous and endothermic. Additionally, the adsorption capacity of MIPs-CAM still reached 85% of the initial result after five cycles. The experimental results revealed that the molecularly imprinted membrane possessed the advantages of high selectivity and easy recovery compared with the traditional molecular imprinted polymers for SA separation. These results indicate that boron affinity MIPs-CAM with high performance will provide a promising platform for the separation and purification of other cis-diol drug molecules from environmental resources.

Teamed Boronate Affinity-Functionalized Zn-MOF/PAN-Derived Molecularly Imprinted Hollow Carbon Electrospinning Nanofibers for Selective Adsorption of Shikimic Acid.

Electrospun micro-/nanofibers with tailor-made specific binding sites are extremely popular due to their tremendous potential in separation applications. In this work, teamed boronate affinity (TBA)-functionalized molecularly imprinted hollow carbon electrospun nanofibers (MI-HCESNFs) derived from ZIF-8/PAN fibers with selective binding sites toward shikimic acid (SA) are presented. Each ingredient used in this strategy plays its own part: HCESNFs with excellent structural characteristics as the highly porous electrospun substrate, KH560 as the grafting material for the follow-up polyethyleneimine (PEI) modification, PEI as the dendritic platform to approach more boronic acid owing to its long chain with abundant amino groups, and TBA molecular group as the functional monomer to specifically bind with SA under the neutral condition. Benefiting from the porous structure, the high density of boronic acid, and the highly accessible imprinted sites on the surface, MI-HCESNFs show strong affinity and selectivity to the SA molecules. The adsorption capacity of MI-HCESNFs can reach 127.8 mg g-1, which is 3.1 times larger than that of the non-imprinted material. Besides, MI-HCESNFs are stable when treated with continuous ultrasonication and can be recycled eight times with a slight loss of 8.615% on the adsorption quantity. This work presents a new strategy to prepare boronate affinity adsorbents based on the electrospinning technique for the capture of SA and also proposes a path for the integration of molecularly imprinted polymers and electrospinning.

Metagenomics analysis of cultured mucosal bacteria from colorectal cancer and adjacent normal mucosal tissues.

Introduction. Colorectal cancer (CRC) is one of the most common cancers worldwide. Multiple risk factors are involved in CRC development, including age, genetics, lifestyle, diet and environment. Of these, the role of the gut microbiota in cancer biology is increasingly recognized.Hypothesis/Gap Statement. Micro-organisms have been widely detected in stool samples, but few mucosal samples have been detected and sequenced in depth.Aim. Analysis of cultured mucosal bacteria from colorectal cancer and adjacent normal mucosal tissues with metagenomics sequencing.Methodology. Twenty-eight paired tumour and non-tumour tissues from 14 patients undergoing surgery for CRC were analysed. We removed the influence of eukaryotic cells via culture. The composition of mucosal microbiota in intestinal mucosa were detected and analysed with metagenomic sequencing.Results. Compared with non-cultured mucosal sample, 80 % bacteria species could be detected after culture. Moreover, after culture, additional 30 % bacteria could be detected, compared with non-cultured samples. Since after culture it was difficult to estimate the original abundance of microbiome, we focused on the identification of the CRC tissue-specific species. There were 298 bacterial species, which could only be cultured and detected in CRC tissues. Myroides odoratimimus and Cellulophaga baltica could be isolated from all the tumour samples of 14 CRC patients, suggesting that these species may be related to tumour occurrence and development. Further functional analysis indicated that bacteria from CRC tissues showed more active functions, including basic metabolism, signal transduction and survival activities.Conclusion. We used a new method based on culture to implement information on prokaryotic taxa, and related functions, which samples were from colorectal tissues. This method is suitable for removing eukaryotic contamination and detecting micro-organisms from other tissues.

Alterations in gut microbiota and metabolites associated with altitude-induced cardiac hypertrophy in rats during hypobaric hypoxia challenge.

The gut microbiota is involved in host responses to high altitude. However, the dynamics of intestinal microecology and their association with altitude-related illness are poorly understood. Here, we used a rat model of hypobaric hypoxia challenge to mimic plateau exposure and monitored the gut microbiome, short-chain fatty acids (SCFAs), and bile acids (BAs) over 28 d. We identified weight loss, polycythemia, and pathological cardiac hypertrophy in hypoxic rats, accompanied by a large compositional shift in the gut microbiota, which is mainly driven by the bacterial families of Prevotellaceae, Porphyromonadaceae, and Streptococcaceae. The aberrant gut microbiota was characterized by increased abundance of the Parabacteroides, Alistipes, and Lactococcus genera and a larger Bacteroides to Prevotella ratio. Trans-omics analyses showed that the gut microbiome was significantly correlated with the metabolic abnormalities of SCFAs and BAs in feces, suggesting an interaction network remodeling of the microbiome-metabolome after the hypobaric hypoxia challenge. Interestingly, the transplantation of fecal microbiota significantly increased the diversity of the gut microbiota, partially inhibited the increased abundance of the Bacteroides and Alistipes genera, restored the decrease of plasma propionate, and moderately ameliorated cardiac hypertrophy in hypoxic rats. Our results provide an insight into the longitudinal changes in intestinal microecology during the hypobaric hypoxia challenge. Abnormalities in the gut microbiota and microbial metabolites contribute to the development of high-altitude heart disease in rats.

Calcium-Mobilizing Properties of Salvia miltiorrhiza-Derived Carbon Dots Confer Enhanced Environmental Adaptability in Plants.

Biomass-derived carbon dots (CDs) are promising nanotools for agricultural applications and function as a reactive oxygen species (ROS) scavenger to alleviate plant oxidative stress under adverse environments. Nevertheless, plants need ROS burst to fully activate Ca2+-regulated defensive signaling pathway. The underlying mechanism of CDs to improve plant environmental adaptability without ROS is largely unknown. Here, Salvia miltiorrhiza-derived CDs triggered ROS-independent Ca2+ mobilization in plant roots. Mechanistic investigation attributed this function mainly to the hydroxyl and carboxyl groups on CDs. CDs-triggered Ca2+ mobilization was found to be dependent on the production of cyclic nucleotides and cyclic nucleotide-gated ion channels. Lectin receptor kinases were verified as essential for this Ca2+ mobilization. CDs hydroponic application promoted Ca2+ signaling and plant environmental adaptability under salinity and nutrient-deficient conditions. All these findings uncover that CDs have a Ca2+-mobilizing property and thus can be used as a simultaneous Ca2+ signaling amplifier and ROS scavenger for crop improvement.

Gut Microbiome-Targeted Modulations Regulate Metabolic Profiles and Alleviate Altitude-Related Cardiac Hypertrophy in Rats.

It is well known that humans physiologically or pathologically respond to high altitude, with these responses accompanied by alterations in the gut microbiome. To investigate whether gut microbiota modulation can alleviate high-altitude-related diseases, we administered probiotics, prebiotics, and synbiotics in rat model with altitude-related cardiac impairment after hypobaric hypoxia challenge and observed that all three treatments alleviated cardiac hypertrophy as measured by heart weight-to-body weight ratio and gene expression levels of biomarkers in heart tissue. The disruption of gut microbiota induced by hypobaric hypoxia was also ameliorated, especially for microbes of Ruminococcaceae and Lachnospiraceae families. Metabolome revealed that hypobaric hypoxia significantly altered the plasma short-chain fatty acids (SCFAs), bile acids (BAs), amino acids, neurotransmitters, and free fatty acids, but not the overall fecal SCFAs and BAs. The treatments were able to restore homeostasis of plasma amino acids and neurotransmitters to a certain degree, but not for the other measured metabolites. This study paves the way to further investigate the underlying mechanisms of gut microbiome in high-altitude related diseases and opens opportunity to target gut microbiome for therapeutic purpose. IMPORTANCE Evidence suggests that gut microbiome changes upon hypobaric hypoxia exposure; however, it remains elusive whether this microbiome change is a merely derivational reflection of host physiological alteration, or it synergizes to exacerbate high-altitude diseases. We intervened gut microbiome in the rat model of prolonged hypobaric hypoxia challenge and found that the intervention could alleviate the symptoms of pathological cardiac hypertrophy, gut microbial dysbiosis, and metabolic disruptions of certain metabolites in gut and plasma induced by hypobaric hypoxia. Our study suggests that gut microbiome may be a causative factor for high-altitude-related pathogenesis and a target for therapeutic intervention.

Targeting of SPCSV-RNase3 via CRISPR-Cas13 confers resistance against sweet potato virus disease.

Sweet potato (Ipomoea batatas) is one of the most important crops in the world, and its production rate is mainly decreased by the sweet potato virus disease (SPVD) caused by the co-infection of sweet potato chlorotic stunt virus (SPCSV) and sweet potato feathery mottle virus. However, methods for improving SPVD resistance have not been established. Thus, this study aimed to enhance SPVD resistance by targeting one of its important pathogenesis-related factors (i.e., SPCSV-RNase3) by using the CRISPR-Cas13 technique. First, the RNA targeting activity of four CRISPR-Cas13 variants were compared using a transient expression system in Nicotiana benthamiana. LwaCas13a and RfxCas13d had more efficient RNA and RNA virus targeting activity than PspCas13b and LshCas13a. Driven by the pCmYLCV promoter for the expression of gRNAs, RfxCas13d exhibited higher RNA targeting activity than that driven by the pAtU6 promoter. Furthermore, the targeting of SPCSV-RNase3 using the LwaCas13a system inhibited its RNA silencing suppressor activity and recovered the RNA silencing activity in N. benthamiana leaf cells. Compared with the wild type, transgenic N. benthamiana plants carrying an RNase3-targeted LwaCas13a system exhibited enhanced resistance against turnip mosaic virus TuMV-GFP and cucumber mosaic virus CMV-RNase3 co-infection. Moreover, transgenic sweet potato plants carrying an RNase3-targeted RfxCas13d system exhibited substantially improved SPVD resistance. This method may contribute to the development of SPVD immune germplasm and the enhancement of sweet potato production in SPVD-prevalent regions.

[Isolation and identification of cholesterol-degrading intestinal bacteria by culturomics and evaluation of their functions].

High cholesterol is one of the important factors inducing cardiovascular and cerebrovascular diseases. Drug therapy is the main method for reducing cholesterol, but has the disadvantages such as high cost and side effects. Studies have shown that intestinal bacteria play important roles in cholesterol metabolism. However, there are few reports on the screening and functional evaluation of cholesterol-lowering intestinal bacteria. In this study, 36 bile-tolerant bacteria were screened from healthy people stool through culturomics using bovine bile acid or artificial mixed bile acids as substrates. Taking Lactobacillus rhamnosus GG (LGG) as a positive control, three bile acid concentration groups (0 g/L, 0.3 g/L, 3 g/L) were set up to evaluate the cholesterol-lowering ability of bile-tolerant bacteria in vitro. Ten bacteria (including Proteus mirabilis, Providencia stuartii, Proteus vulgaris et al) were identified as the dominant cholesterol-lowering bacteria. Six of the above bacteria, Proteus mirabilis, Providencia stuartii, Proteus vulgaris, Proteus penneri, Wohlfahrtiimonas chitiniclastica, Providencia rettger, were evaluated for their ability to reduce triglycerides in vitro and tolerance to artificial gastric juice. Comparing with strain LGG, the six bacteria showed better triglyceride-lowering ability in vitro. With the decrease of pH value of artificial gastric juice and the increase of treatment time, the survival rate of six bacteria decreased. The above screening experiments and functional evaluation provide a basis for further development of potential cholesterol-lowering bacterial products.

Hypoxia: The "Invisible Pusher" of Gut Microbiota.

Oxygen is important to the human body. Cell survival and operations depend on oxygen. When the body becomes hypoxic, it affects the organs, tissues and cells and can cause irreversible damage. Hypoxia can occur under various conditions, including external environmental hypoxia and internal hypoxia. The gut microbiota plays different roles under hypoxic conditions, and its products and metabolites interact with susceptible tissues. This review was conducted to elucidate the complex relationship between hypoxia and the gut microbiota under different conditions. We describe the changes of intestinal microbiota under different hypoxic conditions: external environment and internal environment. For external environment, altitude was the mayor cause induced hypoxia. With the increase of altitude, hypoxia will become more serious, and meanwhile gut microbiota also changed obviously. Body internal environment also became hypoxia because of some diseases (such as cancer, neonatal necrotizing enterocolitis, even COVID-19). In addition to the disease itself, this hypoxia can also lead to changes of gut microbiota. The relationship between hypoxia and the gut microbiota are discussed under these conditions.