Arbuscular mycorrhizal fungi regulate amino acid metabolism, phytohormones and glycolysis pathway to promote the growth of Suaeda salsa under combined Cd and NaCl stresses.

The use of halophytes in conjunction with arbuscular mycorrhizal (AM) fungi has been found to enhance the removal efficacy of heavy metals and salts in heavy metals contaminated saline soil. The mechanisms of AM fungi on promoting halophyte growth and regulating metabolism remain unclear. In this study, combinations of 0 g kg-1 NaCl and 3 mg kg-1 Cd (S0Cd3), 6 g kg-1 NaCl and 3 mg kg-1 Cd (S6Cd3), and 12 g kg-1 NaCl and 3 mg kg-1 Cd (S12Cd3) were employed to explore the impact of Funneliformis mosseae on the growth and metabolism of Suaeda salsa. The results showed that AM fungi increased the biomass and the P, K+, Ca2+, and Mg2+ accumulations, reduced the Cd and Na+ concentrations in S0Cd3 and S6Cd3, and increased the Cd concentrations in S12Cd3. AM fungi inoculation reduced the Cd and Na+ transfer factors and increased the Cd and Na+ accumulations in S6Cd3. The metabolomics of S6Cd3 showed that AM fungi upregulated the expression of 5-hydroxy-L-tryptophan and 3-indoleacid acid in tryptophan metabolism, potentially acting as crucial antioxidants enabling plants to actively cope with abiotic stresses. AM fungi upregulated the expression of arbutin in glycolysis process, enhancing the plants' osmoregulation capacity. AM fungi upregulated the expression of 2-hydroxycinnamic acid in phenylalanine metabolism and dopaquinone in tyrosine metabolism. These two metabolites help effectively remove reactive oxygen species. Correspondingly, AM fungi decreased MDA content and increased soluble sugar content. These results indicate that AM fungi improve the stress resistance of S. salsa by increasing nutrient uptake and regulating physiological and metabolic changes.

[Retracted] MicroRNA­329­3p targets MAPK1 to suppress cell proliferation, migration and invasion in cervical cancer.

Following the publication of the above article, a concerned reader drew to the Editor's attention that certain of the Transwell cell migration and invasion assay data featured in Figs. 5C and 6C were strikingly similar to data appearing in different form in other articles written by different authors at different research institutes that had already been published elsewhere prior to the submission of this paper to Oncology Reports, or were submitted for consideration for publication at around the same time. In view of the fact that certain of these data had already apparently been published prior to the submission of this article for publication, the Editor of Oncology Reports has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Oncology Reports 37: 2743­2750, 2017; DOI: 10.3892/or.2017.5555].

Bio-organic fertilizer promoted phytoremediation using native plant leymus chinensis in heavy Metal(loid)s contaminated saline soil.

Heavy metal(loid)s (HMs) contaminated saline soil appeared around the world, however, remediation regarding these collected from field conditions remains unknown. Native plants cultivation and bio-organic fertilizer (BOF) application were two efficient tools for soil amelioration. Herein, a pot experiment was conducted to examine the feasibility of a native plant (Leymus chinensis) for phytoremediation, and investigate the impacts of lignite based bio-organic fertilizer (LBOF) and manure based bio-organic fertilizer (MBOF) on phytoremediation of the soil contaminated by Pb, Cd, As, Zn, Cu, Ca2+, and SO42-. The results demonstrated the effectiveness of L. chinensis and highlighted the positive impacts of BOF according to the improved plant growth, HMs phytostabilization, salt removal, and soil properties. LBOF and MBOF changed soil microbiome to assist phytoremediation in addition to physiological modulation. Having enhanced fungal and bacterial richness respectively, LBOF and MBOF recruited various plant growth promoting rhizobacteria with different functions, and shifted microbial co-occurrence networks and keystone taxa towards these different but beneficial forms. Structural equation models comprehensively reveled the strategy discrepancy of LBOF and MBOF to regulate the plant biomass, HMs uptake, and soil salt. In summary, L. chinensis coupled with BOF, especially LBOF, was a effective strategy to remediate HMs contaminated saline soil.

Synergistic mechanisms of bioorganic fertilizer and AMF driving rhizosphere bacterial community to improve phytoremediation efficiency of multiple HMs-contaminated saline soil.

The addition of Arbuscular mycorrhizal fungi (AMF) or bioorganic fertilizer (BOF) alone has been reported to enhance plant tolerance to heavy metals and salt stress and promote plant growth, while their synergistic effects on plant growth and rhizosphere microorganism are largely unknown. This study explored the effects of AMF (Rhizophagus intraradices), BOF and BOF + RI assisted phytoremediation on heavy metals contaminated saline soil improvement and revealed the microbial mechanism. For this purpose, a pot trial consisting of four treatments (CK, RI, BOF and BOF + RI) was carried out. The results showed that the biomass, nutrient element contents, the accumulation of heavy metals and Na of Astragalus adsurgens and soil properties were most significantly improved by BOF + RI. BOF + RI significantly impacted rhizosphere microbial diversity, abundance and community composition. Chloroflexi and Patescibacteria at the phylum level and Actinomadura, Iamia, and Desulfosporosinus at the genus level were significantly enriched in BOF + RI. Network analysis revealed that BOF + RI significantly changed the keystone and enhanced complexity and interaction. Most of the keystones had roles in promoting plant growth and stress resistance. This study suggested that phytoremediation assisted by BOF and AMF is an attractive approach to ameliorate heavy metals contaminated saline soil.

Bioorganic fertilizers improve the adaptability and remediation efficiency of Puccinellia distans in multiple heavy metals-contaminated saline soil by regulating the soil microbial community.

Soil salinization and heavy metal (HM) pollution are global environmental problems. Bioorganic fertilizers facilitate phytoremediation, but their roles and microbial mechanisms in natural HM-contaminated saline soils have not been explored. Therefore, greenhouse pot trials were conducted with three treatments: control (CK), manure bioorganic fertilizer (MOF), and lignite bioorganic fertilizer (LOF). The results showed that MOF and LOF significantly increased nutrient uptake, biomass, toxic ion accumulation in Puccinellia distans, soil available nutrients, SOC, and macroaggregates. More biomarkers were enriched in MOF and LOF. Network analysis confirmed that MOF and LOF increased the number of bacterial functional groups and fungal community stability and strengthened their positive association with plants; Bacteria have a more significant effect on phytoremediation. Most biomarkers and keystones play important roles in promoting plant growth and stress resistance in the MOF and LOF treatments. In summary, besides enrichment of soil nutrients, MOF and LOF can also improve the adaptability and phytoremediation efficiency of P. distans by regulating the soil microbial community, with LOF having a greater effect.

Shift in rhizospheric and endophytic microbial communities of dominant plants around Sunit Alkaline Lake.

Alkaline lakes are a special type of extreme saline-alkali ecosystem, and the dominant plants store a large number of microbial resources with salinity-tolerant or growth-promoting properties in the littoral zones. In this study, high-throughput sequencing technology and molecular ecological networks were used to analyze the bacteria and fungi from different rhizocompartments of three dominant plants along the salinity gradient in the littoral zones of Sunit Alkali Lake. The study found that fungal communities were more tolerant of environmental abiotic stress, and salinity was not the main environmental factor affecting the composition of microbial communities. Mantel test analysis revealed that SOC (soil organic carbon) was the primary environmental factor affecting the rhizosphere bacterial community as well as the rhizosphere endophyte bacteria and fungi, while CO32- (carbonate ions) had a greater impact on the rhizosphere fungal communities. In addition, keystones identified through the associated molecular network play an important role in helping plants resist saline-alkali environments. There were significant differences in the metabolic pathways of microorganisms from different rhizocompartments predicted by the PICRUSt2 database, which may help to understand how microorganisms resist environmental stress. This study is of great importance for understanding the salt environments around alkaline lakes and excavating potential microbial resources.

Claroideoglomus etunicatum affects the structural and functional genes of the rhizosphere microbial community to help maize resist Cd and La stresses.

Arbuscular mycorrhizal fungi (AMF) and plant rhizosphere microbes reportedly enhance plant tolerance to abiotic stresses and promote plant growth in contaminated soils. The co-contamination of soil by heavy metals (e.g., Cd) and rare earth elements (e.g., La) represents a severe environmental problem. Although the influence of AMF in the phytoremediation of contaminated soils is well documented, the underlying interactive mechanisms between AMF and rhizosphere microbes are still unclear. We conducted a greenhouse pot experiment to evaluate the effects of AMF (Claroideoglomus etunicatum) on maize growth, nutrient and metal uptake, rhizosphere microbial community, and functional genes in soils with separate and combined applications of Cd and La. The purpose of this experiment was to explore the mechanism of AMF affecting plant growth and metal uptake via interactions with rhizosphere microbes. We found that C. etunicatum (i) significantly enhanced plant nutritional level and biomass and decreased metal concentration in the co-contaminated soil; (ii) significantly altered the structure of maize rhizosphere bacterial and fungal communities; (iii) strongly enriched the abundance of carbohydrate metabolism genes, ammonia and nitrate production genes, IAA (indole-3-acetic acid) and ACC deaminase (1-aminocyclopropane-1-carboxylate) genes, and slightly altered the abundance of P-related functional genes; (iv) regulated the abundance of microbial quorum sensing system and metal membrane transporter genes, thereby improving the stability and adaptability of the rhizosphere microbial community. This study provides evidence of AMF improving plant growth and resistance to Cd and La stresses by regulating plant rhizosphere microbial communities and aids our understanding of the underlying mechanisms.

Exploring Microbial Resource of Different Rhizocompartments of Dominant Plants Along the Salinity Gradient Around the Hypersaline Lake Ejinur.

Lake littoral zones can also be regarded as another extremely hypersaline environment due to hypersaline properties of salt lakes. In this study, high-throughput sequencing technique was used to analyze bacteria and fungi from different rhizocompartments (rhizosphere and endosphere) of four dominant plants along the salinity gradient in the littoral zones of Ejinur Salt Lake. The study found that microbial α-diversity did not increase with the decrease of salinity, indicating that salinity was not the main factor on the effect of microbial diversity. Distance-based redundancy analysis and regression analysis were used to further reveal the relationship between microorganisms from different rhizocompartments and plant species and soil physicochemical properties. Bacteria and fungi in the rhizosphere and endosphere were the most significantly affected by SO4 2-, SOC, HCO3 -, and SOC, respectively. Correlation network analysis revealed the potential role of microorganisms in different root compartments on the regulation of salt stress through synergistic and antagonistic interactions. LEfSe analysis further indicated that dominant microbial taxa in different rhizocompartments had a positive response to plants, such as Marinobacter, Palleronia, Arthrobacter, and Penicillium. This study was of great significance and practical value for understanding salt environments around salt lakes to excavate the potential microbial resources.

Identifying the role of exogenous amino acids in catalyzing lignocellulosic biomass into humus during straw composting.

This study was aimed at exploring the mechanism of promoting humus formation by the addition of exogenous amino acids. Amino acids not only participated in the synthesis of humus directly as precursors, but also changed the functions of bacterial communities. The composition and diversity of bacterial community changed with the addition of amino acids. The ability of bacterial community to degrade lignocellulose was enhanced, which provided precursors for humus synthesis. The key bacteria for humus formation and organic matter transformation were identified using random forests. These bacteria showed growth advantage with the addition of amino acids. The results showed that exogenous amino acids tended to transform organic matter and synthesize humus. Variance partitioning analysis confirmed that the bacterial community was the driving force of humus synthesis. These results were further verified by the structural equation model. These findings provided new ideas and understanding for straw waste composting.

Two types nitrogen source supply adjusted interaction patterns of bacterial community to affect humifaction process of rice straw composting.

This study investigated effects of high-nitrogen source (urea) (R_UR) and protein-like nitrogen source (chicken manure) (R_CM) on humification process during lignocellulose biomass composting. It demonstrated that decreasing ratio of crude fiber (CF), polysaccharide (PS) and amino acids (AAs) in R_CM (29.75%, 53.93% and 73.73%, respectively) was higher than that in R_UR (14.73%, 28.74% and 51.92%, respectively). Humic substance (HS) concentration increased by 7.51% and 73.05% during R_UR and R_CM composting, respectively. The lower total links, more independent modularization and higher proportion of positive correlations between functional bacteria and organic components was observed with R_CM network than R_UR, indicating that protein-like nitrogen source supply may alleviate competition within bacterial community. Moreover, chicken manure supply favorably selects greater special functional bacterial taxa (Pusillimonas, Pedomicrobium, Romboustia and other 24 genus) related to AAs and stimulates the collaborative division of bacterial community. This is significance for strengthening effective transformation of organic components.

Evaluation of Microbial Assemblages in Various Saline-Alkaline Soils Driven by Soluble Salt Ion Components.

Land degraded by salinization and alkalization is widely distributed globally and involves a wide range of ecosystem types. However, the knowledge of the indigenous microbial assemblages and their roles in various saline-alkaline soils is limited. This study demonstrated microbial assemblages in various saline-alkaline soils from different regions of Inner Mongolia and revealed the key driving factors to influence microbiome. The correlation network analysis indicates the difference in adaptability of bacterial and fungal communities under stimulation by saline-alkaline stress: fungal community shows higher tolerance, stability, and resilience to various saline-alkaline soils than a bacterial community. The keystone bacteria and fungi that have potential adaptability to various saline-alkaline environments are further identified, and they may confer benefits in restoring saline-alkaline soils by their own effects or assisting plants. For salt-rich soils in different regions, the soluble salt ion components are the major determinant to drive microbial assemblages of different saline-alkaline soils, rather than salinity. Thus, these saline-alkaline soils are clustered into sulfated, chlorinated, and soda-type saline-alkaline soils. Multivariate analysis reveals unique, dominant, and common microbial taxa in three saline-alkaline soils. This result of the conceptual mode indicates that potential roles of unique and dominant microbial taxa on regulating saline-alkaline functions are more vital.

[Potential of Arbuscular Mycorrhizal Fungi, Biochar, and Combined Amendment on Sandy Soil Improvement Driven by Microbial Community].

Sandy soils are considered as a significant transition phase to desertification. The effective recovery of sandy soils is of great significance to mitigate the desertification process. Some studies have shown that arbuscular mycorrhizal (AM) fungi and biochar improved the sandy soil, but there have been very few studies regarding the combined effects of AM fungi and biochar amendments on sandy soil improvement. Additionally, the roles of the bacterial and fungal community during the process of sandy soil improvement remain unclear. A greenhouse pot experiment with four treatments, including a control (CK, no amendment), single AM fungi-assisted amendment (RI), single biochar amendment (BC), and combined amendment (BC_RI, biochar plus AM fungi), was set up. This study investigated the effects of different amendment methods on the Nitrariasi birica mycorrhizal colonization, biomass, nutrient (N, P, K, Ca, and Mg) content, soil organic carbon, soil nutrient (TN, TP, and TK) content, and soil water-stable aggregate composition. High throughput sequencing technology was used to investigate the roles of the bacterial and fungal communities during the process of sandy soil improvement. Combined with multiple analysis methods, the improvement mechanisms of different amendment methods were explored. The aim was to provide basic data and scientific basics for reasonably and effectively improving sandy soils. The results indicated that a significant mycorrhiza colonization was observed in the inoculation (RI and BC_RI) treatments, but there was no substantial difference in the mycorrhiza colonization with the RI and BC_RI. Compared with the CK, the shoot biomass and shoot element (N, K, Ca, and Mg) contents were significantly increased in the RI, and the shoot element (N, P, K, Ca, and Mg) contents were significantly increased in the BC and BC_RI; compared with the RI and BC, the root biomass and the root element (P, K, Ca, and Mg) contents were significantly increased in the BC_RI. Compared with the CK, the soil organic carbon contents were significantly increased in the BC and BC_RI, the soil TN contents were significantly increased by 152.54%, and the soil TP and TK contents were significantly decreased by 12.5% and 18.8%, respectively. The proportion of soil aggregates with particle sizes of 0.25-0.05 mm was the highest in each treatment, and the large particle size (>0.25 mm) soil aggregate was significantly increased in the BC_RI. Compared with the CK, the Sobs and Shannon indices of the bacterial/fungal community were significantly decreased in the RI and BC_RI. There was a difference in the microbial community compositions and abundance in the various treatments. The results of the RDA and network analysis were as follows:the effects of AM fungi, biochar, and combined amendment on the soil environment and microbial community structure were significant; in the different amendment treatments, the relationship of the microbial molecular ecological network was significantly changed, and the composition of the core species varied; compared with the RI, there was a higher network connection degree and a richer core species composition in the BC and BC_RI; moreover, the essential role of Rhizophagus intraradices was weaken and the core roles of the other microorganisms (especially bacterial species) were enhanced under the combined effects of biochar and AM fungi. The SEM results demonstrated that the application of AM fungi and biochar could directly affect the bacteria/fungi community structure, and further affect the plant growth and soil properties. The differences in the microbial community structure (especially the change in the microbial interaction) were the key driving factors that led to the difference in the soil improvement effectiveness. In summary, the effects of the different amendment methods on the improvement effectiveness of sandy soils varied. The microbial community played key roles in the process of sandy soil improvement, and there were potential advantages and applications in accelerating the ecological restoration of sandy soils under the combined AM fungi and biochar amendment.

Arbuscular mycorrhizal fungi alter microbiome structure of rhizosphere soil to enhance maize tolerance to La.

Rhizosphere microbes are essential partners for plant stress tolerance. Recent studies indicate that arbuscular mycorrhizal fungi (AMF) can facilitate the revegetation of soils contaminated by heavy metals though interacting with rhizosphere microbiome. However, it is unclear how AMF affect rhizosphere microbiome to improve the growth of plant under rare earth elements (REEs) stress. AMF (Claroideoglomus etunicatum) was inoculated to maize grown in soils spiked with Lanthanum (0 mg kg-1, La0; 10 mg kg-1, La10; 100 mg kg-1, La100; 500 mg kg-1, La500). Plant biomass, nutrient uptake, REE uptake and rhizosphere bacterial and fungal community were evaluated. The results indicated that La100 and La500 decreased significantly root colonization rates and nutrition uptake (K, P, Ca and Mg content). La500 decreased significantly α-diversity indexes of bacterial and fungal community. AMF enhanced significantly the shoot and root fresh and dry weight of maize in all La treatments (except for the root fresh and dry weight of La0 and La10 treatment). For La100 and La500 treatments, AMF increased significantly nutrition uptake (K, P, Ca and Mg content) in shoot of maize by 27.40-441.77%. For La500 treatment, AMF decreased significantly shoot La concentration by 51.53% in maize, but increased significantly root La concentration by 30.45%. In addition, AMF decreased bacterial and fungal Shannon index in La0 treatment, but increased bacterial Shannon index in La500 treatment. Both AMF and La500 affected significantly the bacterial and fungal community composition, and AMF led to more influence than La. AMF promoted the enrichment of bacteria, including Planomicrobium, Lysobacter, Saccharothrix, Agrococcus, Microbacterium, Streptomyces, Penicillium and other unclassified genus, and fungi (Penicillium) in La500, which showed the function for promoting plant growth and tolerance of heavy metal. The study revealed that AMF can regulate the rhizosphere bacterial and fungal composition and foster certain beneficial microbes to enhance the tolerance of maize under La stress. Phytoremediation assisted by AMF is an attractive approach to ameliorate REEs-contaminated soils.

Effect of arbuscular mycorrhizal symbiosis on ion homeostasis and salt tolerance-related gene expression in halophyte Suaeda salsa under salt treatments.

Halophytes can remove large quantities of salts from saline soils, so their importance in ecology has received increasing attention. Preliminary studies have shown that arbuscular mycorrhizal (AM) fungi can improve the salt tolerance of halophytes. However, few studies have focused on the molecular mechanisms and effects of AM fungi in halophytes under different salt conditions. A pot experiment was carried out to investigate the effects of Funneliformis mosseae inoculation on growth, nutrient uptake, ion homeostasis and the expression of salt tolerance-related genes in Suaeda salsa under 0, 100, 200 and 400 mM NaCl. The results showed that F. mosseae promoted the growth of S. salsa and increased the shoot Ca2+ and Mg2+ concentrations under no-salt condition and high-salt condition. In addition, AM fungi increased the K+ concentration and maintained a high K+/Na+ ratio at 400 mM NaCl, while AM fungi decreased the K+ concentration and reduced the K+/Na+ ratio at 0 mM NaCl. AM fungi downregulated the expression of SsNHX1 in shoots and the expression of SsSOS1 in roots at 400 mM NaCl. These effects may decrease the compartmentation of Na+ into leaf vacuoles and restrict Na+ transport from roots to shoots, leading to an increase in root Na+ concentration. AM symbiosis upregulated the expression of SsSOS1 in shoots and downregulated the expression of SsSOS1 and SsNHX1 in roots at 100 mM NaCl. However, regulation of the genes (SsNHX1, SsSOS, SsVHA-B and SsPIP) was not significantly different with AM symbiosis at 0 mM or 200 mM NaCl. The results revealed that AM symbiosis might induce diverse modulation strategies in S. salsa, depending on external Na+ concentrations. These findings suggest that AM fungi may play significant ecological roles in the phytoremediation of salinized ecosystems.

Rescuing Dicer expression in inflamed colon tissues alleviates colitis and prevents colitis-associated tumorigenesis.

Chronic inflammation is known to promote carcinogenesis; Dicer heterozygous mice are more likely to develop colitis-associated tumors. This study investigates whether Dicer is downregulated in inflamed colon tissues before malignancy occurs and whether increasing Dicer expression in inflamed colon tissues can alleviate colitis and prevent colitis-associated tumorigenesis. Methods: Gene expression in colon tissues was analyzed by immunohistochemistry, immunoblots, and real-time RT-PCR. Hydrogen peroxide or N-acetyl-L-cysteine was used to induce or alleviate oxidative stress, respectively. Mice were given azoxymethane followed by dextran sulfate sodium to induce colitis and colon tumors. Berberine, anastrozole, or pranoprofen was used to rescue Dicer expression in inflammatory colon tissues. Results: Oxidative stress repressed Dicer expression in inflamed colon tissues by inducing miR-215 expression. Decreased Dicer expression increased DNA damage and cytosolic DNA and promoted interleukin-6 expression upon hydrogen peroxide treatment. Dicer overexpression in inflamed colon tissues alleviated inflammation and repressed colitis-associated carcinogenesis. Furthermore, we found that anastrozole, berberine, and pranoprofen could promote Dicer expression and protect cells from hydrogen peroxide-induced DNA damage, thereby reducing cytosolic DNA and partially repressing interleukin-6 expression upon hydrogen peroxide treatment. Rescuing Dicer expression using anastrozole, berberine, or pranoprofen in inflamed colon tissues alleviated colitis and prevented colitis-associated tumorigenesis. Conclusions: Dicer was downregulated in inflamed colon tissues before malignancy occurred. Decreased Dicer expression further exaggerated inflammation, which may promote carcinogenesis. Anastrozole, berberine, and pranoprofen alleviated colitis and colitis-associated tumorigenesis by promoting Dicer expression. Our study provides insight into potential colitis treatment and colitis-associated colon cancer prevention strategies.

Effect of tricarboxylic acid cycle regulators on the formation of humic substance during composting: The performance in labile and refractory materials.

The aims of this study are to reveal the roles of tricarboxylic acid (TCA) cycle regulators in reducing CO2 emission and promoting humic substance (HS) formation during composting with different materials. The results showed that the addition of adenosine tri-phosphate (ATP) or malonic acid (MA) reduced CO2 emission during chicken manure composting. However, only the addition of MA reduced CO2 emission during lawn waste and garden waste composting. In addition, both of the two inhibitors promoted HS formation, especially for ATP. Structural equation models further confirmed that ATP and MA reduced CO2 emission by inhibiting the decomposition of amino acid by microorganisms. Meanwhile, ATP promoted the conversion of amino acid and soluble sugars to HS, while MA only promoted the conversion of soluble sugars to HS. In summary, this study provides a theoretical basis for the application of inhibitors to reduce CO2 emission and promote HS formation during composting.

Effects of exogenous protein-like precursors on humification process during lignocellulose-like biomass composting: Amino acids as the key linker to promote humification process.

The aim of this study is to assess the effectiveness of protein-like precursors addition on promoting humification process during lignocellulose-like biomass composting through adding amino acids to compost. The humification indexes of R1 and R2 was significantly higher than that of CK (P < 0.05). The decreasing ratio of Maillard precursor concentration of R2 and R1 was higher than CK. Amino acids addition affected the bacteria community and environmental factors during composting. Variance partitioning analysis showed that humification process was strengthened with environmental factors, bacteria community, Maillard precursors. Structural equation model (SEM) analysis showed that amino acids had substantial impact on promoting humic acid (HA) formation. The combined application of protein-like wastes and lignocellulose-like wastes was suggested to improve carbon sequestration. This study lays a foundation for economically and effectively managing different types of straws by composting.

Effect of the addition of exogenous precursors on humic substance formation during composting.

The aim of this work was to explore the effect of the addition of exogenous precursors on humic substance (HS) formation during composting. HS formation is a complex biochemical process that occurs during composting. In addition, HS precursors and bacterial communities were recognized as the key factors that affect HS formation. The addition of exogenous precursors can promote the humification process during composting, but few studies have explored the potential relationships between the proportion of additional exogenous precursors, the bacterial community and HS formation. Jointly adding benzoic acid (BA) and soybean residue after extracted oil (SR) treatment can promote HS formation, especially humic acid formation. In addition, the increase in the proportion of exogenous precursors added could strengthen the relationship among different precursors, thereby changing the bacterial community composition and further promoting the humification process during composting. In addition, a structural equation model (SEM) showed that precursors were the key factors to regulate HS formation and certain bacteria as the direct drivers to affect HS formation. This model provides more possibilities to regulate HS formation during composting and enhances its potential applicability under real conditions.

MicroRNA-34a promotes MICB expression in hepatocytes.

MicroRNA-34a (miR-34a) behaves as a tumor suppressor by decreasing the expression of oncogenes involved in multiple carcinogenic pathways. Intravenous delivery of miR-34a mimics has been investigated in clinical trials as a potential treatment for advanced cancers; however, the effect of miR-34a on cancer immune surveillance is controversial. In the current study, we found that miR-34a plays a dual role in the regulation of major histocompatibility complex class I-related sequence B (MICB) protein, a ligand of the NKG2D receptor. MiR-34a could both induce and reduce MICB expression by upregulating ataxia telangiectasia and Rad3-related (ATR) protein kinase and downregulating the transcription factor E2F1, respectively. The net effect of miR-34a on MICB expression depended on endogenous E2F1 levels. Overexpression of miR-34a promoted MICB expression in hepatocytes and hepatocellular carcinoma (HCC) cells that have low E2F1 levels but not in HCC cells that have high E2F1 levels. In HCC patients, the expression of miR-34a and MICB showed positive correlation in paratumor liver tissues, which have low E2F1 levels, but not in HCC tissues, which have high E2F1 levels. We showed that miR-34a overexpression in non-transformed liver cells enhanced cytolysis and interferon-γ production by NK-92MI cells. Furthermore, higher miR-34a expression in tumor and paratumor tissues was associated with positive and negative outcomes, respectively, in HCC patients. Our findings suggest that miR-34a induces MICB expression in paratumor liver tissues, which may cause liver damage and serious cytokine release syndrome, thus disclosing potential side effects of systemic administration of miR-34a in anticancer therapy.

Al2O3 nanoparticle impact on the toxic effect of Pb on the marine microalga Isochrysis galbana.

The rapid development and application of nanotechnology have led to increasing concern about the environmental implications of released nanomaterials and potential risks to public health and aquatic ecosystems. Information on the joint effect of nanomaterials and co-existing contaminants such as heavy metals is still inadequate. Our work investigated the effect of Al2O3 nanoparticles (NPs; nano-Al2O3) on the toxic effect of Pb in the unicellular marine phytoplankton Isochrysis galbana. Results showed that a dose-response effect of nano-Al2O3 was found. Significant enhancement of fluorescence in cell cytoplasm rather than cell membrane occurred in the presence of nano-Al2O3, indicating that nano-Al2O3 can penetrate cells and affect the fluorescence emitted from the chloropigments inside them. The presence of nano-Al2O3 has no impact on the toxic effect of Pb at an NP concentration of 1 mg/L but increased that at NP concentrations of 10 mg/L and 100 mg/L. A synergistic effect was also found for the toxic effect of Pb in the presence of 10 mg/L nano-Al2O3. The presence of 100 mg/L nano-Al2O3 significantly increased the bio-uptake of Pb in the range of 0.25 mg/L to 2.0 mg/L Pb, and the maximum accumulated Pb in algae can reach up to 18.22 ng/105 cells with 100 mg/L nano-Al2O3 compared with Pb alone at 2.0 mg/L(12.53 ng/105 cells). Inside cells, Pb loaded onto nano-Al2O3 can be more toxic than the same amount of free Pb species. The results of toxicity tests and accumulated Pb in algae imply that, in addition to the total Pb cell content, the bioavailability of Pb inside algae should be taken into consideration in evaluating the joint toxicity effect. Our work enhances understanding of the combined toxicity of NPs and co-existing heavy metals and is of practical significance in the natural environment.