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The defects, micropores, and microcracks on the plasma electrolytic oxidation (PEO) coating severely affect the long-term anti-corrosion feature. Inclusion of additives in the electrolyte is a feasible and effective strategy to attain the more intact PEO coating. The PEO coatings are fabricated on AZ31B Mg alloys in an silicon-based electrolyte with Na 3 VO 4 (OPEO), NaVO 3 (MPEO), and V 2 O 3 (VPEO), respectively, to explore the influence of additives on the corrosion resistance. MPEO sample has the smallest poriness and pore size unfolding the best anti-corrosion resistance, which is also consistent with the electrochemical analysis. Even after 336 h salt spray test, the MPEO coating exhibits the least corrosion. The excellent anti-corrosion performance of MPEO sample is the synergistic effect of inorganic salts and multiple metal oxides generated in the formation of PEO coating. Inclusion of inorganic salt with valence change metal is a feasible pathway to achieve the compact PEO coating since multiple metal oxides could be produced and deposited in the PEO coating during the fabrication. • Inorganic salt with valence change metal is taken as the additive. • PEO coating with NaVO 3 additive is not corroded after 14 days salt spray test. • Multiple species generated in the PEO process prompts the improved feature. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ionic liquid is firstly utilized as the electrolyte additive for Mg-air battery. • Discharge potential and utilization efficiency are both boosted. • Working mechanism of [Ch][DHB] as electrolyte additive is clarified. • [Ch][DHB] is also suitable for other commercial Mg anodes, AM50, AZ31, and ZK61. A novel ionic liquid, choline 2,6-dihydroxytbenzoate ([Ch][DHB]), is firstly synthesized and utilized as the electrolyte additive for aqueous Mg-air cell based on the high purity Mg (Hp-Mg) with the aim to enhance the discharge performance. The half-cell discharge test, electrochemical measurement, and real-time hydrogen evolution are carried out to evaluate the influence of [Ch][DHB] and clarify the working mechanism. The [DHB]- anion could bind the Mg2+ ions to form the complex, which is beneficial to prompt the discharge of Mg matrix; while the [Ch]+ cation is effective to inhibit the self-corrosion of Mg anode. With the addition of 0.2 M [Ch][DHB] in the 3.5 wt% NaCl, both discharge potential and utilization efficiency are enhanced to −1.64 V SCE and 68.0 % under 5 mA cm−2. Based on the above Mg-air cell, 66 of LED bulbs (0.04 W/per bulb) would be maintained for 132 h with 0.2 M [Ch][DHB] in the electrolyte, while they are only kept for 65 h in the reference electrolyte. The 0.2 M [Ch][DHB] is also suitable electrolyte additives for Mg-air battery based on other commercial Mg anodes (AM50, AZ31, and ZK61). The specific energy of Mg-air batteries based on Hp-Mg, AM50, AZ31, and ZK61 in 0.2 M [Ch][DHB] electrolyte are 2093 Wh kg−1, 1788 Wh kg−1, 1896 Wh kg−1, and 713 Wh kg−1 at 5 mA cm−2, respectively. This work exhibits a promising pathway to enhance the discharge performance of Mg-air primary battery, including both discharge potential and utilization efficiency, with ionic liquids as electrolyte additives. [ABSTRACT FROM AUTHOR]

Enterococcus faecalis and Staphylococcus aureus are frequently co-isolated from biofilm-associated infections. A new study by Ch'ng et al. revealed that S. aureus -released heme feeds E. faecalis respiration, augmenting E. faecalis growth and overall biofilm biomass. Their finding further supports the theory that metabolite cross-feeding is a critical aspect shaping polymicrobial biofilm interactions. [ABSTRACT FROM AUTHOR]

Two Cu(II) metal complexes, {[Cu(bmem)(CH 3 OH)(CH 3 O)](ClO 4)} n (1) and {[Cu(bmem)(CH 3 O)(SCN)](CH 3 OH) 0.75 } n (2) based on 1-(benzotriazole-1-methyl) -1-(2-ethylimidazole) (bmem) were synthesized. The X-ray single crystal diffraction analysis reveals that complexes 1 and 2 both display 1D chain structure containing binuclear copper units. Then the ligand and complexes 1 and 2 were examined for hypoglycemic activity against α-amylase and antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and found that two Cu(II) complexes showed more activity than the ligand bmem. Both complexes 1 and 2 have strong inhibitory effects on α-amylase, and the IC 50 values of complexes 1 (1.97 mg/mL) and 2 (1.83 mg/mL) are lower than that of acarbose (2.3 mg/mL) and ligand (10.89 mg/mL). The scavenging rates on DPPH radical of complexes 1 (80.46%, 150 μg/mL) and 2 (63.08%, 150 μg/mL) are significantly higher than that of ligand (6.92%, 150 μg/mL). In addition, the fluorescence properties and thermal stability of metal complexes were determined. Image 1 • Two new benzotriazole-based Cu(II) complexes 1 and 2 were synthesized. • Complexes 1 and 2 display 1D chain structure containing binuclear copper units. • The hypoglycemic activities against α-amylase of complexes 1 and 2 were investigated in vitro. • The antioxidant activities of complexes 1 and 2 were evaluated by the DPPH free radical scavenging assay. [ABSTRACT FROM AUTHOR]

Three new complexes formulated as [Cu(mbmb) 2 Cl 2 ] (1), [Cu(mbmb) 2 (NO 3) 2 ] (2), and [Zn(mbmb) 2 Cl 2 ] (3) (mbmb = 1-[(2-methyl-1H-benzoimidazol-1-yl)methyl]-1H-benzotriazole) have been synthesized and characterized. Complexes 1 – 3 showed mononuclear structures and the central metal ions of complexes 1 – 3 exhibited a four-coordinated environment. We evaluated the antioxidant activity against DPPH and antidiabetic activity against α-amylase of complexes 1 – 3 and ligand (mbmb) in vitro. The results of DPPH free radical scavenging assay showed that complexes 1 and 2 exhibited higher antioxidant activity among the synthesized compounds and their IC 50 values were 43.72 μg/mL and 43.76 μg/mL, respectively. The IC 50 values in vitro antidiabetic studies of complex 1 (0.74 mg/mL) and complex 2 (1.00 mg/mL) were much smaller than those of standard acarbose (2.34 mg/mL) and the ligand mbmb (39.87 mg/mL), which showed effective inhibition on α-amylase. Additionally, the solid-state fluorescent properties of these three complexes and ligand mbmb were investigated at room temperature. Unlabelled Image • Three new benzimidazole-based Cu(II)/Zn(II) complexes 1 – 3 were synthesized. • The structure of complexes 1 – 3 was characterized adequately by X-ray study. • The antioxidant activities of complexes 1 – 3 were evaluated by the DPPH free radical scavenging assay. • The antidiabetic activities against α-amylase of complexes 1 – 3 were investigated in vitro. [ABSTRACT FROM AUTHOR]

Plasma electrolytic oxidation (PEO) coating has been widely applied for the magnesium alloys to resist the corrosion. However, the defaults on the PEO surface greatly weaken its long-term anti-corrosion performance. To fill the micropores is an efficient and feasible strategy to refine the compactness and anti-corrosion of PEO coating and achieve the additional function. Although various sealing pathways are reported in past decades, the leakage of filler and long-term anti-corrosion performance are still the perplexing issues. The corrosion inhibitor 1-methyl-3-(carboxyundecyl)imidazolium bis(trifluoromethylsulfonyl)imide ([MCIM][NTf 2 ], MN), is grafted on the clinochrysotile-like magnesium silicate nanotubes (MSNTs) by the post-synthesis method, then, the MSNTs@MN is filled into the micropores on the PEO surface by the post-sealing process to form PEO/MSNTs@MN. According to the electrochemical results in 3.5 wt% NaCl solution, the log |Z| 0.01Hz is increased by 1.26 times after the sealing. After immersion in 3.5 wt% NaCl solution for 120 h, the log |Z| 0.01Hz of PEO/MSNTs@MN is still the 1.56 times larger than that of PEO. The PEO coating filled by the MSNTs@MN offers the consistently superior corrosion resistance up to 336 h of salt spray tests with 5.0 wt% NaCl solution. The superior anti-corrosion performance of PEO/MSNTs@MN is associated with the cooperation of physical barrier of PEO coating and protection from MSNTs@MN. The grafted corrosion inhibitor would not leak easily, which is favorable to achieve the long-term anti-corrosion performance. The immobilized MN provides the active anti-corrosion in the initial corrosion stage achieving the self-healing function. Moreover, the release of corrosion inhibitor, MN, does not rely on the smart trigger, which broadens the scope of immobilized materials. This work introduces a facile and one-step strategy to seal the pores on the PEO surface with the self-healing function and improved anti-corrosion capability. [Display omitted] • Novel hybrid coating PEO/MSNTs@MN with self-healing and long-term anti-corrosion • A simple one-step strategy is introduced to seal the pores on the PEO surface. • The immobilized MSNTs@MN provides the active anti-corrosion functionalization. • Anti-corrosion feature is kept after 336 h salt spray tests in 5 wt% NaCl. [ABSTRACT FROM AUTHOR]

• Fertilization regimes affected straw-C incorporation into amino sugars. • Higher 13C-fungal residues accumulated in NPK plus manure supplied soil. • Higher straw-13C transformed into bacterial C in NPK-treated soil. • NPKM soil sustained greater recovery of 13C in total amino sugars by the end. • Straw-13C amino sugars contributed differentially to 13C-SOC in different soils. Emerging evidences have emphasized the primacy of microorganisms as executor in soil organic C (SOC) formation. Yet, whether and how microbial transformation of crop residue-derived C into necromass is affected by fertilization regimes remains poorly understood. To address this, soils subjected to 3-year applications of chemical fertilizer (NPK) vs manure plus chemical fertilizer (NPKM) were incubated with or without addition of 13C-labelled rice straw for 60 days. The 13C incorporation into amino sugars (microbial necromass biomarker) was identified by using an amino sugar-based stable isotope probing approach. The straw-C were transformed more rapidly into total amino sugars (13C-AS s) in NPK-treated soil, while more pronounced 13C-AS s accumulation occurred in NPKM soil at later stage, indicating temporal microbial C uptake to generate necromass varied depending on fertilization regimes. Moreover, straw-derived fungal C was significantly higher in NPKM over NPK while bacterial counterpart reversed during the incubation. Our results reinforced changes in microbial communities and their C utilization capacities for efficient residue production in different fertilized soils. Additionally, NPKM-treated soil sustained a prolonged but likely more efficient utilization of straw-C with increasing time as evidenced by significantly higher percentage of straw-dervied C enrichment in 13C amino sugar pools by the end of incubation. These findings reveal that fertilization regimes can alter response strategies of microbial transformation of plant C into microbial-derived C. Together with differential contributions of these newly-formed microbial C to SOC pool, our work highlights the key role of microbial anabolisms in building up SOC following crop residue return to soils under different fertilization regimes. [ABSTRACT FROM AUTHOR]

Biodiversity can effectively actuate ecosystem multifunctionality, and the relationships primarily depend on the circumstances. However, the relative functional importance of particular components in complex biocoenosis, such as abundant and rare taxa, influencing soil multifunctionality changes across environmental gradients and remains limited understanding. Here, 152 independent soil samples from aridity (from 0.47 to 0.97) and elevation (from 142 to 2766 m a.s.l.) gradients across steppes of northern China were collected and analyzed to obtain information of soil bacterial community and soil functional properties, which were further utilized to evaluate how the relationships between the diversities of abundant and rare species and soil multifunctionality respond to changes in aridity and elevation. At aridity and elevation levels of ~0.85 and ~1100 m a.s.l., respectively, abrupt variations of the connections between soil multifunctionality and diversities of abundant or rare taxa occurred. Moreover, the results revealed a significantly positive effect of richness of abundant taxa on soil multifunctionality in the less arid and higher elevation areas, whereas a strongly positive relationship was exhibited between diversity of rare species and soil multifunctionality in the more arid and higher elevation regions. Specially, regardless of higher or lower aridity levels, both contributions of abundant and rare taxa to soil multifunctionality were extremely weak in the lower elevation regions. Our study highlights the importance of aridity and elevation impacting the contributions of abundant and rare taxa in regard to soil multifunctionality, which can positively provide some theoretical bases for promoting ecosystem sustainability and productivity under global climate change. • Abrupt shifts occurred at aridity and elevation levels of about 0.85 and 1100 m a.s.l., respectively. • Abundant taxa showed a positive effect in the less arid and higher elevation areas. • Rare taxa exhibited a positive effect in the more arid and higher elevation areas. • Both abundant and rare taxa showed weak effects in the lower elevation regions. [ABSTRACT FROM AUTHOR]

Highlights • Richness and phylogenetic diversity indexes were similar in the different treatments and soil type. • Bacterial abundance and phylogenetic diversity decreased significantly following N enrichment. • N fertilization and soil type individually or jointly mediated the bacterial community structure. • Soil microbial parameters coupled with abiotic factors contributed directly and indirectly to maize yields. Abstract Although the effects of nitrogen (N) fertilization on soil microflora have been well studied, the effects should be verified across soil types and N-added levels. To understand the impacts of N fertilization on shifts in soil biological traits and bacterial communities and to further explore the coupling mediation of these parameters with respect to crop yields, we sampled soils from three experimental sites (each site received three levels of N fertilization (0, 168 and 312 kg N ha−1)) that share the same climatic conditions but have different soil types (clay, alluvial and sandy soils). In clay and sandy soils, total microbial biomass with N fertilization treatments was lower than that with no treatment, and the N and carbon (C) contents of microbial biomass with N fertilization treatments were higher than those without treatment. In alluvial soils, these properties were higher with N fertilization treatment than with no treatment. Together with N addition, bacterial abundance and phylogenetic diversity significantly decreased in alluvial and sandy soils. Soil type had a higher (38.82%, p < 0.001) individual impact on bacterial community structure than did N fertilization (18.92%, p < 0.001). Interactions between soil type and N fertilization also notably explained 11.08% of the altered community structure. Overall, N fertilization significantly affected soil physicochemical (such as pH, organic C and NO 3 --N) and biological properties (microbial biomass C and N), which can affect maize yield directly and indirectly by further mediating soil bacterial abundance, diversity and community structure, with consequences for crop production. Bacterial community structure (path coefficient = 0.64) had the most positive and direct impact on maize yield, followed by organic C (0.37) and available N (0.33). Altogether, these findings suggest that N fertilization affects soil biological traits and bacterial communities across different soil types. Further understanding these soil microbial parameters can contribute to crop yield and may provide deeper insight into predicting the coupling of soil functionality and crop productivity. [ABSTRACT FROM AUTHOR]

Ammonia oxidation, the primary and rate-limiting step of nitrification, is mediated by both ammonia-oxidizing archaea (AOA) and bacteria (AOB). However, the dominant environmental driver of the activity, abundance, diversity and composition of ammonia-oxidizers has not been well understood enough, and the relative contribution of AOA and AOB to nitrification is still under debate. Soils treated with different fertilization regimes in an over 35-year field experiment were collected to explore the variation in function and structure of ammonia-oxidizer communities and corresponding driver. The highest nitrification activity (44.49 mg N kg −1 soil d −1 ) was found in only organic fertilizer (O) treated soil, whereas the lowest activity (2.81 mg N kg −1 soil d −1 ) was observed in only mineral fertilizer (NPK) treated soil. Moreover, as 1-octyne was employed to discriminate AOA- and AOB-supported nitrification, AOA dominated (93.53%) the nitrification in the Control soil, while AOB contributed dominantly (84.73–89.10%) in all of the organic amended soils, and NPK-treated soil showed an almost equal contribution to AOA (45.79%) and AOB (54.21%). Compared with the Control soil, AOA abundance increased in soils with organic and low chemical fertilizer but decreased in only chemically treated soil, whereas the AOB abundance in all fertilized soils was greatly enhanced. The AOA activity was linearly dependent on AOA abundance, whereas the AOB activity was exponentially correlated with AOB abundance. The sequences of AOA and AOB in the Control soil were mostly affiliated with group I.1b thaumarchaeota and genus Nitrosospira clusters 3a.1. Soil treated with NPK increased the abundance of AOA that belonged to group I.1a-associated lineage, whereas more abundant AOB was related to Nitrosospira clusters 3a.2 and 8b. In contrast, the O-treated soil showed more abundant AOB that belonged to Nitrosospira clusters 3b and 8b. As revealed by aggregated boosted tree analysis, the soil ammonium (NH 4 + ) content was identified as the dominant driver of activity and diversity of AOA, and soil pH was considered to be the major influencing factor in abundance and composition of AOA; the AOB composition was mainly affected by soil NH 4 + content, the relative activity and diversity by soil pH, and the relative abundance by soil electrical conductivity (EC). Collectively, different fertilization regimes will result in variations in activity, abundance, diversity and composition of ammonia-oxidizers with distinct drivers. Our research could be helpful to identify better strategies for the mitigation of nitrate production in agricultural soils. [ABSTRACT FROM AUTHOR]

We introduce a facile and robust strategy for bonding a poly(methylmethacrylate) (PMMA) thermoplastic microdevice via ethanol treatment followed by thermal bonding at relatively low temperature and low pressure. Organic solvents can speed up bonding without sacrificing the optical properties of the PMMA substrate, but microchannels are often clogged by the solvent during the bonding process. To prevent channel clogging while achieving robust sealing, a microchannel was selectively treated hydrophobically, and then the entire surface of the PMMA was treated with ethanol at 80 °C for 30 min. Two pieces of PMMA were thermally pressed together at 60 °C for 20 min to obtain a permanent seal. Tensile strength measurement, high-throughput leakage test, and burst test were performed. The highest bonding strength was approximately 12.4 MPa, and the bonding was robust enough to endure intense liquid flow that was almost 450 times higher than the total internal volume of the microchannel. [ABSTRACT FROM AUTHOR]

Anti-corrosion inorganic-organic hybrid coating with the self-healing feature is still scare for the Mg alloys. The adhesion between various compositions is one troublesome problem. On the other hand, the incorporation of corrosion inhibitor would destroy the feature of organic film leading to the inferior anti-corrosion performance. The hybrid coating, PEO/IN/QSE, with the self-healing feature is firstly fabricated on Mg alloys, in which the corrosion inhibitor of imidazolium-based ionic liquid (IN) is embedded in the plasma electrolytic oxidation (PEO) pores and the superhydrophobic film (QSE) is covered on the top. The IN embedded in the pores of PEO layer does not destroy the feature of QSE film and improve the anti-corrosion performance of PEO layer. And it affords the self-healing function, which is determined by the anti-corrosion test with the scratched samples. More important, it strengthens the adhesion between QSE and PEO coating as a bridge. This work provides a feasible strategy to prepare the inorganic-organic composite film with the promising applications for the anti-corrosion of the Mg alloys. [Display omitted] • Composite coating PEO/IN/QSE with self-healing and superhydrophobic feature • Adhesion between PEO and QSE layer is strengthened by IN. • The pores of PEO are taken as the container for IN corrosion inhibitor. [ABSTRACT FROM AUTHOR]

Both nitrogen (N) and phosphorus (P) may limit plant production in steppes and affect plant community structure. However, few studies have explored in detail the differences and similarities in the responses of belowground microbial communities to long-term N and P inputs. Using a high-throughput Illumina Miseq sequencing platform, we characterized the bacterial communities in a semi-arid steppe subjected to long-term N or P additions. Our results showed that both the Chao richness and Shannon's diversity were negatively correlated to N input rate, while only Chao richness was significantly and negatively correlated to P input rate. Also, both N and P additions altered the bacterial community structure. The bacterial community between plots of the same N or P input rate was much more dissimilar with the higher input level, indicating more severe niche differentiation in pots with higher N or P input. N Inputs significantly increased the relative abundance of the predicted copiotrophic groups ( Proteobacteria and Firmicutes ) but reduced the predicted oligotrophic groups ( Acidobacteria , Nitrospirae , Chloroflexi ), with the order Rhizobiales being most affected. P additions significantly affected only two phyla (Armatimonadetes and Chlorobi ), which were positively correlated with P source. Results from the structural equation modelling (SEM) showed that N additions affected the bacterial community primarily by changing the pH, while P additions did so mainly by improving P availability. Our results suggest that the below-ground bacterial communities are more sensitive to N inputs, but P inputs can also play an important role in bacterial niche differentiation. These findings improve our understanding of bacterial responses to N and P inputs, and their impacts on bacterial-mediated processes, especially in the context of increasing anthropogenic nutrient inputs. [ABSTRACT FROM AUTHOR]

The volatile organic compounds (VOCs) produced by soil microbes have a significant role in the control of plant diseases and plant growth promotion. In this study, we examined the effect of VOCs produced by Pseudomonas fluorescens strain WR-1 on the growth and virulence traits of tomato wilt pathogen Ralstonia solanacearum . The VOCs produced by P. fluorescens WR-1 exhibited concentration dependent bacteriostatic effect on the growth of R. solanacearum on agar medium and in infested soil. The VOCs of P. fluorescens WR-1 also significantly inhibited the virulence traits of R. solanacearum . The proteomics analysis showed that the VOCs of P. fluorescens WR-1 downregulated cellular proteins of R. solanacearum related to the antioxidant activity, virulence, inclusion body proteins, carbohydrate and amino acid synthesis and metabolism, protein folding and translation, methylation and energy transfer, while the proteins involved in the ABC transporter system, detoxification of aldehydes and ketones, protein folding and translation were upregulated. This study revealed the significance of VOCs of P. fluorescens WR-1 to control the tomato wilt pathogen R. solanacearum . Investigation of the modes of action of biocontrol agents is important to better comprehend the interactions mediated by VOCs in nature to design better control strategies for plant pathogens. [ABSTRACT FROM AUTHOR]

Significant differences in the microbial biomass and diversity in soil have been observed following long-term fertilization, but little research has explored the co-occurrence patterns among microbial taxa or functions. Soil samples from four long-term experiments in China were collected, and an Illumina amplicon sequencing of 16S rDNA amplicon was performed to decipher the differences in interactions and network organization arising from fertilization with organic amendment (OA) or chemical fertilizer (CF) across the sampling sites. We thus aimed to extend the analysis beyond the basic inventory descriptions of the composition and diversity of the microbiome and toward an assessment of relationships and effects. Nonmetric multidimensional scaling analysis revealed a clear difference between the soil microbiomes associated with the OA and CF treatments. Fertilization can interact with the soil chemical properties and sampling site, thereby significantly impacting the associated soil microbiome. Distinct network structures indicated that the OA network was characterized by more functionally interrelated operational taxonomic units (OTUs) than the CF network. The topological roles of individual OTUs and key microbial populations were distinctly different, although the generalists mainly belonging to Actinobacteria and Proteobacteria were observed in both networks. The different fertilization treatments had distinct effects on the soil pH, which represented a key variable to impact the associated microbial community modularity. Most functional groups involving carbon-, nitrogen- and phosphorus-related metabolism and recycling and antibiotic biosynthesis were present at significantly high abundance in the organic-amended soils. All of the functions with statistical significance could be traced to corresponding responsible major modules in the CF network, but it was not the case in OA soil. These results suggested that the soil functions were decentralized and assigned to small groups in OA soil. Overall, we demonstrated that long-term organic amendment supports stronger functional potentials and more interactions within soil community relative to long-term chemical-only fertilization, which may be related to OA benefits to soil stability and buffering capacity. These results explore the correlations, inter-taxa and between major groups and functional traits, to gain a more integrated understanding of microbiome and ecological rules guiding soil community fostered by fertilization regimes. [ABSTRACT FROM AUTHOR]

Abstract: The application method for a novel bioorganic fertilizer (BIO) was developed to improve its biocontrol efficacy of Fusarium wilt (Ling et al. 2010). However, its efficacy on controlling Fusarium wilt and the variations of microbial community after long-term application for watermelon production had not been elucidated. To clarify, a 4-years pot experiment of mono-cropping watermelon was conducted. The results revealed that though the disease incidences were increased in all treatments with the increase of continuous cropping years, the treatment of BIO application both in nursery and pot soil always maintained the lowest disease incidence. The real-time PCR results showed that the population of Paenibacillus polymyxa was decreased with continuous cropping years, but in all seasons, the treatment with BIO application both in nursery and pot soil had a highest population of P. polymyxa than the other treatments. On the other hand, the abundance of the pathogen FON was increased with the increase of continuous cropping years and the lowest rate of increase was found by BIO application in both nursery and pot soil. DGGE patterns showed that the bacterial diversity was weakened after mono-cropping of watermelon for 4 years, but the consecutive applications of BIO at nursery and transplanting stage resulted in the minimal change of bacterial diversity. More detailed differences on bacterial diversity between control and double application of BIO treatment after 4-years monoculture were analyzed by 454 pyrosequencing, which showed the dominant phyla found in both samples were Firmicutes, Proteobacteria and Actinobacteria, and the consecutive applications of BIO recruited more beneficial bacteria than control, such as Bacillus, Paenibacillus, Haliangium, Streptomyces. Overall, these results, to a certain extent, approved that the consecutive applications of BIO at nursery and transplanting stage could effectively suppress watermelon Fusarium wilt by regulating the rhizosphere bacterial diversity. These results could give some clues that how to regulate the soil microbial community to an appropriate level which can keep the plant healthy and thus control the soil-borne diseases. [Copyright &y& Elsevier]

Abstract: Infection with the soil-borne pathogen Fusarium oxysporum f. sp. cucumerinum (FOC), which causes Fusarium wilt of cucumber plants, might result in changes in plant transpiration and water status within leaves. To monitor leaf response in cucumber infected with FOC, digital infrared thermography (DIT) was employed to detect changes in leaf temperature. During the early stages of FOC infection, stomata closure was induced by ABA in leaves, resulting in a decreased transpiration rate and increased leaf temperature. Subsequently, cell death occurred, accompanied by water loss, resulting in a little decrease in leaf temperature. A negative correlation between transpiration rate and leaf temperature was existed. But leaf temperature exhibited a special pattern with different disease severity on light–dark cycle. Lightly wilted leaves had a higher temperature in light and a lower temperature in dark than did in healthy leaves. We identified that the water loss from wilted leaves was regulated not by stomata but rather by cells damage caused by pathogen infection. Finally, water balance in infected plants became disordered and dead tissue was dehydrated, so leaf temperature increased again. These data suggest that membrane injury caused by FOC infection induces uncontrolled water loss from damaged cells and an imbalance in leaf water status, and ultimately accelerate plant wilting. Combining detection of the temperature response of leaves to light–dark conditions, DIT not only permits noninvasive detection and indirect visualization of the development of the soil-borne disease Fusarium wilt, but also demonstrates certain internal metabolic processes correlative with water status. [Copyright &y& Elsevier]

Abstract: Fusarium wilt of banana is caused by Fusarium oxysporum f. sp. cubense infection. The initial chlorosis symptoms occur progressively from lower to upper leaves, with wilt symptoms subsequently occurring in the whole plant. To determine the effect of the pathogen infection on the gas exchange characteristics and water content in banana leaves, hydroponic experiments with pathogen inoculation were conducted in a greenhouse. Compared with control plants, infected banana seedlings showed a higher leaf temperature as determined by thermal imaging. Reduced stomatal conductance (gs) and transpiration rate (E) in infected plants resulted in lower levels of water loss than in control plants. Water potential in heavily diseased plants (II) was significantly reduced and the E/gs ratio was higher than in noninfected plants, indicating the occurrence of uncontrolled water loss not regulated by stomata in diseased plants. As no pathogen colonies were detected from the infected plant leaves, the crude toxin was extracted from the pathogen culture and evaluated about the effect on banana plant to further investigate the probable reason of these physiological changes in Fusarium-infected banana leaf. The phytotoxin fusaric acid (FA) was found in the crude toxin, and both crude toxin and pure FA had similar effects as the pathogen infection on the physiological changes in banana leaf. Additionally, FA was present at all positions in diseased plants and its concentration was positively correlated with the incidence of disease symptoms. Taken together, these observations indicated that FA secreted by the pathogen is an important factor involved in the disturbance of leaf temperature, resulting in uncontrolled leaf water loss and electrolyte leakage due to damaging the cell membrane. In conclusion, FA plays a critical role in accelerating the development of Fusarium wilt in banana plants by acting as a phytotoxin. [Copyright &y& Elsevier]

Abstract: We previously developed a method for the application of bioorganic fertilizer to improve the biocontrol efficacy of Fusarium wilt (). However, the detailed behavior of Fusarium oxysporum f. sp. niveum (FON) and its antagonistic bacterium, Paenibacillus polymyxa SQR-21 (SQR-21), in the rhizosphere of watermelon after application of the bioorganic fertilizer had not been elucidated. A rhizobox experiment was carried out to investigate the distribution of FON and its antagonistic bacterium, SQR-21, in the soil at different distances from the watermelon rhizoplane by real-time PCR. The results confirmed that the bioorganic fertilizer (BIO) significantly suppressed Fusarium wilt and promoted the growth of the watermelon plants. Furthermore, we found that the application of BIO significantly enhanced the abundance of SQR-21 and reduced the population of FON in the soil near the rhizoplane as compared to the control. A maximal quantity (7.14log10copies/g soil) of P. polymyxa SQR-21 was obtained in the rhizosphere under the BIO treatment, and this number was decreased with increasing distance from the rhizoplane. The population of FON in the rhizosphere of the control was 2 orders of magnitude higher than under the BIO treatment, and with increasing distance from the rhizoplane, the FON abundance increased in the SQR-21 inoculated treatments and decreased in the treatments without SQR-21. In the soil far from the rhizoplane (bulk soil), both FON and SQR-21 reached a level that was not statistically different between the treatments, which might be attributed to the background level of the infested soil. The localization and pattern of colonization of SQR-21 on the root surface was examined in an in vitro experiment by following green fluorescent protein (gfp)-labeled SQR-21. The colonization of P. polymyxa SQR-21 was found to occur at any site on the roots, yet it was preferentially found in defined regions of the root tip and root bend. These results revealed that the BIO applied with the developed method suppressed Fusarium wilt by the promotion of SQR-21 colonization in the rhizosphere, which largely reduced the population of the pathogen. The findings also indicated that the method of nursery application of BIO satisfies the ecological requirements of the biocontrol products. [Copyright &y& Elsevier]

Abstract: Paenibacillus polymyxa can serve as a biocontrol agent with a broad host range, but knowledge of the possible contribution of root exudates to its colonization of the rhizosphere remains limited. In this experiment, we identified several organic acids in the root exudates of watermelon. Chemotaxis and swarming assays were performed to investigate the ability of these organic acids to induce the motility of P. polymyxa SQR-21. Oxalic acid, malic acid and citric acid were present in the root exudates but only the intermediate products in tricarboxylic acid cycle, i.e., malic acid and citric acid, could significantly induce motility in P. polymyxa SQR-21. The maximal inducing ability was obtained with malic acid. Values for malic acid were 3.9 and 1.5 times higher than the control in the chemotaxis assay and the swarming assay, respectively. An in vitro experiment further confirmed that these intermediate products in tricarboxylic acid cycle could promote recruitment to P. polymyxa SQR-21, thereby increasing the population in the rhizosphere. In conclusion, some of the organic acids secreted by roots could play an important role in root colonization of SQR-21. This finding contributes to our understanding of the interactions of bacteria and plants under natural conditions. [Copyright &y& Elsevier]

Abstract: The asymmetric traveling salesman problem (ATSP) appears in various applications. Although there are several heuristic approaches to its solution, the problem is still a difficult combinatorial optimization problem. This work proposes a novel hybrid approach specialized for the ATSP. The proposed method incorporates an improved genetic algorithm (IGA) and some optimization strategies that contribute to its effectiveness. In the IGA, both the crossover operation and the mutation operation are improved by selecting the optimum from a set of solutions. Three strategies: immigration, local optimization and global optimization are established based on several empirical optimization strategies to improve the evolution of the IGA. Computational experiments are conducted on 16 ATSP instances available in the TSPLIB (traveling salesman problem library). The comparative study shows that our proposed approach outperforms several other published algorithms. [Copyright &y& Elsevier]

• The application of animal manures significantly increased the abundance and diversity of ARGs. • Composted pig, chicken and cattle manures had similar influence on the level of soil ARGs. • Repeated manure addition led to the enrichment and accumulation of ARGs in soil over time. • Bacterial population and MGEs were the major drivers for shaping the antibiotic resistome in soil. The application of animal manure is generally considered an important transmission pathway for antibiotic resistance genes (ARGs) in soil. Nevertheless, the fate of ARGs in soil where manure from different sources has been repeatedly implemented is not fully understood. Thus, the succession of ARGs and bacterial communities following the repeated application of three types of animal manures (pig, chicken, and cow manure) to agricultural soil were investigated using Illumina sequencing analysis and high-throughput qPCR. Results showed that manure application remarkably increased the abundance of soil ARGs by increasing the enrichment of indigenous ARGs and introducing extrinsic ARGs. There were no prominent differences in the abundance or diversity of ARGs among the three different manured soils. The abundance and diversity of ARGs in manured soils increased over three consecutive years. Additionally, the abundance of mobile gene elements (MGEs) and bacteria were positively correlated with ARGs, while the changes in the ARG profiles were dramatically associated with the MGEs and bacterial communities. These findings imply that repeated manure application may facilitate to the accumulation and persistence of the soil resistome by regulation of the bacterial community and horizontal gene transfer, providing better insights into the temporal dynamics of soil ARGs in agro-ecosystems. [ABSTRACT FROM AUTHOR]

PhoD -harboring microorganisms are crucial for the regulation of soil phosphorus (P) cycling through the secretion of alkaline phosphomonoesterases and are also known to be sensitive to fertilizer inputs. However, the impacts of long-term mineral and organic fertilizer inputs on active phoD -harboring functional communities in soils remain largely unknown. In the present study, 18O-DNA-stable isotope probing coupled with high-throughput sequencing was utilized in order to characterize active phoD -harboring functional bacterial communities in soils subjected to long-term no-fertilizer (Control), mineral-only fertilizer (NPK), organic-only fertilizer (M), and the combination of mineral and organic fertilizer (NPKM) amendments. Total and active phoD gene abundance decreased in soils amended with long-term mineral fertilizer, but increased in soils under organic fertilizer amendment, compared with the non-fertilized soils. A total of 51 active phoD -harboring bacterial OTUs, mainly belonging to Actinobacteria, were identified in this study. Organically amended soils harbored a higher diversity of active bacterial community. In the active phoD -harboring functional community, Rhodococcus comprised approximately 99% of the total relative abundance in the unfertilized soil, whereas Nocardiopsis and Bacillus accounted for approximately 62% and 24%, respectively, in mineral-only fertilized soils. Active phoD -harboring communities were dominated by members of the genera Streptomyces (26–60%), Nocardia (5–9%) and Gordonia (23–41%) in all organically fertilized soils, including M and NPKM. Overall, these long-term fertilization regimes altered the abundance, richness and composition of the active phoD -harboring functional microbial community. This study provides novel insights into the responses of the active functional bacterial community that is responsible for soil P mineralization to differing long-term fertilization regimes. • The active phoD -harboring bacteria was identified by 18O-DNA-SIP technique. • Organic amendment increased the abundance and diversity of active phoD bacteria. • Different fertilization regimes shaped distinctive active phoD bacterial community. • The active phoD bacterial OTUs in fertilized soils was dominated by Actinobacteria. • In unfertilized soil, ~99% active phoD -harboring OTUs belonged to the Rhodococcus. [ABSTRACT FROM AUTHOR]

Three new Zn(II) complexes, namely [Zn(emimb) 2 Cl 2 (1), [Zn(dmimb) 2 Cl 2 (2) and [Zn(bmem) 2 (SCN) 2 (3), have been synthesized using the benzotriazole-based ligands, 1-((2-ethyl-4-methyl-1H-imidazol-1-yl)methyl)-1H-benzotriazole (emimb), 1-((2,4-dimethyl-1H-imidazol-1-yl)methyl)-1H-benzotriazole (dmimb) and 1-((2-ethyl-1H-imidazol-1-yl)methyl)-1H-benzotriazole (bmem). All the complexes were fully characterized by elemental analysis, IR spectroscopy, 1H NMR spectroscopy and single-crystal X-ray diffraction analysis. Complexes 1–3 show mononuclear structures and the central Zn(II) ion of 1 – 3 is four-coordinated in a distorted tetrahedral coordination geometry. Complex 2 presents an interesting 3-D network through two different intermolecular π-π stacking interactions. The antidiabetic activities against α-amylase of ligands and complexes 1–3 are investigated in vitro. The results indicate that the three Zn(II) complexes inhibit α-amylase more strongly than free ligands. Antioxidant tests in vitro show that the complex 3 possesses a mild antioxidant activity against 1,1-diphenyl-picrylhydrazyl (DPPH). In addition, the solid-state photoluminescence properties of ligands and their Zn(II) complexes have been investigated. Image 1 • Three new benzotriazole-based Zn(II) complexes 1–3 were synthesized. • The structure of complexes 1–3 was characterized adequately by X-ray study. • The antidiabetic activities of complexes 1–3 were investigated against α-amylase in vitro. • The antioxidant activities of complexes 1–3 were evaluated by the DPPH free radical scavenging assay. [ABSTRACT FROM AUTHOR]

• A novel Co(II) complex (1) was synthesized and characterized adequately by X-ray study. • The Co(II) complex exhibits a interesting 3-D framework with the Schläfli symbol of (4·82) 2 (84·122)(42·84) 2. • The antidiabetic activity against α-amylase of complex 1 was investigated in vitro. • The antioxidant activity of complex 1 was evaluated by the DPPH free radical scavenging assay. A novel 3D Co(II) complex {[Co 3 (TTTMB) 4 (SCN) 6 ]·3.5H 2 O} n (1) has been synthesized through the reaction of a flexible tripodal ligand 1,3,5-tris(triazol-1-ylmethyl)- 2,4,6-trimethylbenzene (TTTMB) with Co(NO 3) 2 and KSCN. Single crystal X-ray diffraction determination shows that complex 1 crystallizes in the monoclinic space group C2/c and exhibits three crystallographically independent Co(II) ions with the similar coordination environment but different bond lengths and angles. The overall structure of complex 1 can be described as a (3,4)-connected network with the topological notation of (4·82) 2 (84·122)(42·84) 2. The antidiabetic activity against α-amylase and antioxidant activity against 1,1-diphenyl-2-picrylhydrazil (DPPH) of complex 1 are evaluated in vitro. The IC 50 values of the complex 1 on α-amylase and DPPH are 1.27 mg/mL and 1.53 mg/mL, respectively, which are lower than those of corresponding standard acarbose (2.89 mg/mL) and vitamin E (2.39 mg/mL), indicating that the complex 1 is a new potential antidiabetic and antioxidant drug. Additionally, the solid-state fluorescent properties and thermal stability of the complex are investigated at room temperature. [ABSTRACT FROM AUTHOR]

• Hydrochar derived from food waste was reused as a soil amendment. • Saturated hydraulic conductivity was increased by hydrochar. • Unsaturated hydraulic conductivity and sorptivity were decreased by hydrochar. • Infiltration was limited due to the soil water repellency induced by hydrochar. Hydrothermal carbonization of food waste (FW) and application of the solid product (hydrochar, HC) in agriculture, is expected to be an effective way to promote the circulation in food-energy-water nexus. However, little is known on the effects of applying FW-derived HC as a soil amendment on soil properties and functions. The current study investigated the effects of FW-derived HC on soil hydraulic properties and infiltration process. Two types of FW-derived HC were mixed into the top 0–20 cm soil layer at a rate of 1 % and 2 % (w/w) in a soil column experiment with grass growth. In-situ infiltration experiment was conducted within the soil column using a disc infiltrometer at different negative pressure (−20 cm, −6 cm, and −2 cm water head). Unsaturated hydraulic conductivity (K 0) and sorptivity (S 0) at each negative pressure head was estimated by fitting experimental cumulative infiltration data to a 4-terms infiltration model. Saturated hydraulic conductivity (K s) and soil water retention curve (SWRC) were measured using undisturbed soil cores taken from the soil column. Soil pore size distribution and soil water constants were estimated from the SWRCs. The results indicate that application of FW-derived HC significantly (p < 0.05) affected soil structure by increasing meso (0.03–0.0002 mm) and macro (> 0.03 mm) pores, which can be attributed to the promoted soil aggregation. Saturated hydraulic conductivity was significantly increased and water retention characteristics were changed with significantly (p < 0.05) increased soil water holding capacity and plant available water content. Besides, FW-derived HCs were found hydrophobic and can render wettable sandy soil water repellent. The K 0 and S 0 were significantly (p < 0.05) decreased and cumulative infiltration was reduced when soil was wetted from an initial dry condition. Negative effect was found on grass growth with significantly (p < 0.05) decreased aboveground biomass after HCs application. Our study indicates that agriculture application of FW-derived HC as a soil amendment could effectively improve soil fertility by recycling nutrient elements and improving soil structure. However, attention should be paid to the hydrophobicity and phototoxicity of FW-derived HC to avoid the related detrimental influences on plant growth and environment. [ABSTRACT FROM AUTHOR]

Cotton production in a long-term, consecutive, mono-cropping cotton field has greatly suffered from soil-borne diseases. In this study, a 4-year field experiment was conducted to investigate the effects of organic fertilizer (OF) or bio-fertilizer (BF) combined with a reduced chemical fertilizer (CF) on soil physicochemical properties, biological activities, antagonistic bacteria ( Bacillus, Trichoderma and Pseudomonas ) and pathogen( Fusarium and Verticillium dahliae ). Soil physicochemical and biological properties were significantly affected by different fertilization scenarios. Soil bulk density (BD) decreased by 4.69% more with 60% CF + BF treatment than with 60% CF + OF treatment. Compared with CF treatment, 60% CF + BF treatment significantly increased soil chemical properties of total nitrogen (TN), available phosphorus (AP), available potassium (AK), soil organic carbon (SOC) and dissolved organic carbon (DOC). The resistant enzymatic activities of catalase (CAT), peroxidase (POD), polyphenoloxidase (PPO) and fluorescein diacetate (FDA) were improved by the bio-fertilizer addition. The abundances of Bacillus , Trichoderma and Pseudomonas followed the order of BF > OF > CF > control. The gene copy numbers of Fusarium and Verticillium dahliae were 3.18 and 2.25 cfu × 10 3 · (g · soil) −1 with CF treatment; these decreased by 47% and 32% with 80% CF + OF treatment, respectively, and they further decreased by 86% and 46% with 80% CF + BF treatment, respectively. Together, our results demonstrated that both OF and BF significantly strengthened the enzyme activities, and the antagonistic bacterial abundance but suppressed pathogens, BF was superior to OF in regulating soil microbial abundance, particularly at a high application rate, and highlighted that SOC and AP ( P < 0.05) were positively correlated with antagonistic bacteria, whereas soil BD and pH were the dominant environment factors impacting soil pathogens. Therefore, ameliorating soil TN, AP and SOC statuses using organic or bio-fertilizer combined with chemical fertilizer is a promising approach to maintaining soil microbiota balance in a continuous, mono-cropping cotton field. [ABSTRACT FROM AUTHOR]

Photosynthesis-related factors play a crucial role in plant metabolism and could be involved in defense against pathogens. To investigate the interaction between photosynthesis and defense response, hydroponic experiments with Fusarium oxysporum f. sp. cubense (FOC) infection or without the pathogen were conducted in greenhouse. During the early stage of disease development (after 8 days infection), Fusarium -infected banana seedlings exhibited decreases in photosynthesis rate and stomatal conductance without damage to Photosystem II (PSII). As disease progressed (after 10 days infection), the maximum quantum efficiency of PSII photochemistry decreased. Simultaneously, decreases in the maximum carboxylation efficiency and the chlorophyll content of infected plants were observed. In addition, an increased photorespiration rate and defense reactions were detected in banana plants at the same infection stage. Also, the activity of defense enzymes increased notably, which was associated with the accumulation of phenolic acid and lignin. H 2 O 2 and malate, peaked following FOC infection. A decreased photorespiration rate following exposure to weak light was probably related to the earlier chlorosis of infected plants. Our results demonstrate that early FOC infection induced a decrease in net photosynthetic rate, which mainly resulted from stomatal limitation, and the damage to chloroplasts also contributed to the reduction in the photosynthetic capacity of banana plants in the later stages of infection. The increased photorespiration rate was possibly involved in the resistance of banana plants in the later stages of infection, suggesting an interaction between host plant resistance and the pathogen associated with photosynthesis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel hybrid coating is fabricated with superhydrophobic and self-healing features. • Anti-corrosion feature is maintained for 80 days immersion in 3.5 wt% NaCl. • Incorporation of [OTP][NTf 2 ] offers the self-healing as well as anti-corrosion. • Synergistic cooperation of various constituents results in the outstanding feature. Although Magnesium (Mg) alloys have many distinct advantages, they are vulnerable to the corrosion even in the neutral environment. Effective and feasible anti-corrosion strategies are desirable for the wide application of Mg alloys. A novel anti-corrosion composite coating, MAO (micro-arc oxidation)/[OTP][NTf 2 ] (octadecyl triphenyl phosphonium bis(trifluoromethylsulfonyl)amide)/PSE (superhydrophobic silica/epoxy resin), is fabricated for Mg alloys by combination of MAO, ionic liquid, and superhydrophobic coating. The employed [OTP][NTf 2 ] is incorporated into the pores of MAO coating rather than doped in the PSE coating. The successful preparation of composite coating is characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDXS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The anti-corrosion feature is measured by potentiodynamic polarization curves (PDP) and electrochemical impedance spectroscopy (EIS) in 3.5 wt% NaCl solution. The composite coatings maintain excellent corrosive resistance after 80 days immersion in 3.5 wt% NaCl solution. It is attributed to the synergistic effect of the superhydrophobic feature, the corrosion inhibition of [OTP][NTf 2 ], and the physical barrier of the MAO coating. Even if the coating is scratched, it still exhibits the excellent anti-corrosion performance after immersion in 3.5 wt% NaCl solution for 25 days due to the repair ability of [OTP][NTf 2 ]. The incorporation of [OTP][NTf 2 ] not only offers the self-healing feature but also seals the pores on the MAO surface, which is favorable to enhance the overall anti-corrosion performance of composite coating. [ABSTRACT FROM AUTHOR]

[Display omitted] • Microbial generalists and specialists were investigated at the global scale. • Generalists and specialists simultaneously contributed to species interactions. • Generalists had higher diversification and transition rates than specialists. • Generalists were more characterized by stochastic processes than specialists. • Generalists dampened microbial biogeographical patterns. Microbial generalists and specialists are thought to have distinct impacts on community dynamics, while there have been limited efforts to estimate their contribution to microbial diversity. We aimed to resolve this research gap in microbial ecology to strengthen our understanding of the biogeography of microbial diversity, with implications for global-scale biodiversity mapping. Herein, we identified the ecological characteristics of microbial generalists and specialists across over 3,000 farmland soil samples from eleven countries that encompassed seven climate types. Considering the distinct distributions of generalists and specialists in degree of connexions, betweenness and as key species in network topology, both generalists and specialists contributed to species interactions, though through different modalities. A stronger signature of deterministic processes in specialists indicated their lower tolerance to environment fluctuations. Generalists, in contrast, were more characterized by stochastic processes with higher diversification and transition rates that suggested more important roles in maintaining community stability when exposed to environmental disturbances. The relationship between latitude and diversity combining with distance-decay effects showed that generalists dampened microbial biogeographical patterns, with contrasting impacts by specialists. By demonstrating the ecological characteristics of microbial generalists and specialists, this study deepens our understanding of microbial diversity and highlights the need to impart systematic distinctions among different categories of species when modelling and predicting the fate of ecosystems in the face of global climate change, rather than assuming that species are functionally equivalent. [ABSTRACT FROM AUTHOR]

Hydrochar aging may mitigate the adverse effects of direct hydrochar application on plant growth. However, little is known about the strategies for accelerating aging process and the microbiological mechanisms involved. This study explored the effects of three aging strategies, including the addition of straw and efficient-degrading microorganisms, on the aging processes of food waste-derived hydrochar, and identified the key microbial drivers. The bacterial and fungal sequencing was performed to estimate the species composition in hydrochar at different aging periods (i.e., day 1, 7, 14 and 35). The results showed that the addition of straw and microbial inoculum improved the maximum reaction temperature by 13%, and shortened the aging time by ∼30%. Three bacterial guilds, mainly including Bacillus -like species, were identified that showed significant correlations with the nitrogen and phosphorus dynamics during aging. This study demonstrates the feasibility of manipulating key microbial guilds artificially to achieve efficient harmless-treatment of hydrochar. [Display omitted] • Straw and microbial inoculum addition reduced aging duration by 30%. • Microbial inoculum addition increases the aging reaction temperature by 13%. • Bacteria, rather than fungi, play the critical role in hydrochar aging. • Bacillus and related species drive nitrogen and phosphorus cycles of aging. [ABSTRACT FROM AUTHOR]

Three organic fertilizers made of different animal and plant waste materials (BOFs) were evaluated for their effects on the production of antibacterial volatile organic compounds (VOCs) by two Bacillus amyloliquefaciens strains SQR-9 and T-5 against the tomato wilt pathogen Ralstonia solanacearum (RS). Both strains could produce VOCs that inhibited the growth and virulence traits of RS; however, in the presence of BOFs, the production of antibacterial VOCs was significantly increased. The maximum inhibition of growth and virulence traits of RS by VOCs of T-5 and SQR-9 was determined at 1.5% BOF2 and 2% BOF3, respectively. In case of strain T-5, 2-nonanone, nonanal, xylene, benzothiazole, and butylated hydroxy toluene and in case of strain SQR-9, 2-nonanone, nonanal, xylene and 2-undecanone were the main antibacterial VOCs whose production was increased in the presence of BOFs. The results of this study reveal another significance of using organic fertilizers to improve the antagonistic activity of biocontrol agents against phytopathogens. [ABSTRACT FROM AUTHOR]

Organic-inorganic fertilization has been proven to maintain sustainable rice production. However, the chemical nitrogen (N) fertilizer reduction and its underlying mechanisms have not been revealed under organic-inorganic fertilization. The objective of this study was to quantify how organic-inorganic fertilization affected rice yield and the source-sink relationship during grain filling. A two-year field experiment was conducted during the rice growing seasons of 2021 and 2022, with two organic fertilizer levels (-M, 0 kg ha−1 and +M, 3000 kg ha−1), and five N rates (N0: 0 kg ha−1, N90: 90 kg ha−1, N180: 180 kg ha−1, N270: 270 kg ha−1, N360: 360 kg ha−1). Rice yield and yield components, agronomic N use efficiency (AE), leaf area index (LAI), chlorophyll content, and source-sink traits were examined. Compared with -M treatment, organic-inorganic fertilization increased rice yield. Rice yield for N180 + M was comparable to that for N270 and N360 in two years, while AE total N significantly increased 22.29% compared to N360. LAI and SPAD value were also increased under organic-inorganic fertilization. The rice sink growth and source activity increased with the increase of N rate and organic fertilization. Compared with -M treatment, organic-inorganic fertilization showed higher sink growth and source capacity. Rice yield was source-limited under -M and +M treatments, while organic fertilizer application could increase the source/sink ratio. Meanwhile, we found that the source/sink ratio was significantly positively correlated with rice grain yield. Partial least squares path modeling (PLS-PM) showed that organic-inorganic fertilization optimized source-sink balance by increasing source capacity and sink growth, thereby increasing the rice yield. The high rice yield of organic-inorganic fertilizer over N fertilizer could be explained by its higher sink growth and source capacity. Considering comprehensively yield, AE, and source-sink balance, a combination of N rate of 180 kg ha−1 and organic fertilization of 3000 kg ha−1 was the optimal organic-inorganic fertilization management practice. The study provides a scientific basis for chemical N reduction in rice production and contributes to the promotion of agriculture sustainable development. • Source-sink traits were quantified under organic-inorganic (N + M) fertilization. • The key to increasing rice yield is to optimize the source-sink balance. • Sink growth, source capacity and source/sink ratio under N + M were higher. • LAI and SPAD value were also increased under N + M. • N (180 kg ha−1) + M (3000 kg ha−1) was the optimal practice to improve rice yield. [ABSTRACT FROM AUTHOR]

Soil microbial communities mix and interact, a widespread phenomenon known as community coalescence. However, in the context of different coalescence degrees, the effects and potential applicability of soil mixing on plant disease resistance have not been studied. Here, we mixed soils from two habitats (healthy and diseased soils) at different mixing ratios for watermelon planting. Rhizosphere soils were collected for amplicon sequencing to study the effects of different degrees of bacterial community coalescence on plant growth and disease resistance, as well as on the characteristics, network complexity and stability of rhizosphere microbial communities. Combined with network and cohesion analyses, we found that mixing in more healthy soil reduced the plant disease index and increased biomass by improving the stability and complexity of the network; positive cohesion, reflecting degree of cooperation, was also negatively correlated with the plant disease index. The rhizosphere from healthy soils enriched the core taxa, Nitrospirillum and Singulisphaera. These core taxa were significantly associated with disease suppression and important for regulating the positive cohesion and modularity of the networks. Overall, these findings revealed that the soil bacterial community coalescence enhanced the stability and complexity of the rhizobacterial network, simultaneously core taxa enhanced microbial potential cooperation and network complexity, ultimately enhancing plant health and biomass. Our results provide insights into the understanding of microbial community coalescence as a potentially effective mechanism for improving plant microbial community function and suggest promising new tools for improving plant fitness via mixing soil microbiota. • Community coalescence by soil mixing had positive effects on plant growth and disease-suppression. • More healthy soils resulted in higher positive cohesion and network stability and complexity. • Cooperative behaviours among taxa improved plant resistance to disease. • Core bacterial species strengthen microbial cooperation and network complexity. [ABSTRACT FROM AUTHOR]

Soil plays a crucial role as a significant reservoir for antibiotic resistance genes (ARGs). Despite the extensive research conducted in this area, there remains a need for further investigation, particularly concerning diverse types of agricultural soil. This comprehensive study examined Fusarium wilt diseased and healthy soil samples to investigate the spectrum of ARGs and identify bacteria potentially harboring these genes. The level of antibiotic resistance (AR) in the two soil types was detected by using culture plate counts (PC). We quantified and identified antibiotic resistant bacteria (ARB) against nine antibiotics. From the PC results, the relative number of ARB (number of ARB/total number culturable bacteria) resistant to erythromycin, lincomycin, sulfonamides, streptomycin sulfate, kanamycin, and enrofloxacin in the diseased soil was significantly higher than that in the healthy soil (One-way ANOVA, p < 0.01). The GeoChip (version 5.0) was employed to identify ARGs and antibiotic biosynthetic genes (ABGs). Interestingly, despite the presence of similar ARGs in both soil types, the Fusarium wilt diseased soil demonstrated a significantly elevated abundance of the tetracycline (tetX) resistance gene compared to the healthy soil. A robust correlation (r ≥ 0.8) between multidrug efflux pumps and ARGs indicates that natural antibiotics as selective pressures for transportation mechanisms. Our analysis identified diverse ARB phylotypes and multiple ARGs in both soil types. Incorporating these soil types into ARGs risk assessments and relevant monitoring is essential for a comprehensive understanding of AR dynamics in various environments. [Display omitted] • Fusarium wilt diseased soil had more ARB with antibiotics than healthy soil. • A high abundance of the tetX gene in diseased soil indicates tetracycline resistance. • Efflux pump & ARG show a strong link (r ≥ 0.8), implying antibiotic driven transport. [ABSTRACT FROM AUTHOR]

Abstract: Fusarium wilt is a major disease that causes severe losses in crop yield. Fusaric acid (FA), a non-specific fungal toxin produced by many Fusarium species, can accelerate the wilting of many crops. Unraveling the role of FA in the wilt process can enrich the understanding of the mechanism of pathogenesis. To investigate the dynamic process of the cucumber''s response to FA, we used digital infrared thermography (DIT) to detect leaf temperature during the alternation of light and dark conditions in greenhouse hydroponic experiments. During FA treatment, we found that the leaf temperature of cucumber plants increased when stomata closure was induced by FA. Under the alternation of light and dark, FA-treated plants had a higher leaf temperature in the light and a lower temperature in the dark, when compared to untreated plants. To confirm the uncontrolled water loss was from damaged leaf cells, as a result of FA treatment, and not from the stomata, an experiment was conducted using a split-root system in which spatially separated cucumber roots were each supplied 0 ppm or 100 ppm of FA. In the split-root system, the low temperature areas of the leaves in the dark had a higher FA concentration and more severe membrane injury than the high temperature areas, demonstrating that FA is primary xylem transported. We concluded that membrane injury caused by FA led to non-stomata water loss and, ultimately, to wilting. Combining the response of the leaves under the light and dark conditions with the DIT employed in the present study permitted noninvasive monitoring and direct visualization of wilting development. [Copyright &y& Elsevier]

Abstract: Fusarium wilt is one of the major constraints on cucumber production worldwide. The introduction of beneficial microorganisms into soil has been widely adopted for suppression of the causative soilborne pathogen Fusarium oxysporum f. sp. cucumerinum J. H. Owen. The goal of this study was to investigate the effects of the new bio-organic fertilizer (BIO A) made from organic fertilizer and Bacillus subtilis SQR 9 on Fusarium wilt control in pot experiments. The results showed that application of BIOs significantly decreased the Fusarium wilt disease incidence and promoted plant biomass. The average disease incidence in BIO-treated plants was reduced by 68%, compared with the control treatment. Application of BIO A strongly reduced the number of the pathogen. The copy number of F. oxysporum DNA in BIO-treated soil declined to 105/g fresh root 60 days after pathogen attack, while those in the control treatment remained high (107/g fresh root). To determine the mechanisms of the antagonistic strain, polymerase chain reaction was used to screen SQR 9 for genes involved in biosynthesis of antibiotics. Amplicons of the expected sizes were detected as yndJ involved in the biosynthesis of Yndj protein, qk involved in subtilisin, sboA involved in subtilosin, bamC involved in bacillomycin, ituA, ituB, ituC and ituD involved in iturin, fenB and fenD involved in fengycin, and srfAB involved in surfactin synthesis. Fengycin and bacillomycin production in its culture filtrate were detected by liquid chromatography coupled with mass spectroscopy. The antifungal compounds significantly inhibited mycelial growth of F. oxysporum and caused a 13.4–83.6% reduction in the number of germinated spores compared with the control treatment. We speculate that the antibiotic production can be linked to the mechanism of protection of plants from pathogen attack by SQR 9. [Copyright &y& Elsevier]

Abstract: Aim of the study: Wei-Chang-An-Wan (WCAW), a traditional pharmaceutical preparation, has been used for treating various gastrointestinal (GI) diseases for several decades, but it is still poorly understood how it works on those disorders. This study was to investigate the effects of WCAW extract on GI tract. Materials and methods: The activities of the methanol extract (ME) of WCAW on castor oil-induced diarrhoea, gastrointestinal transit (GIT) in mice, and contractions of isolated rabbit jejunum were investigated. We further assessed the safety of ME in vivo. Additionally, a HPLC fingerprint of ME was appraised to ensure its chemical consistency. Results: Ten peaks were identified in the HPLC fingerprint of ME. At the doses of 400 and 800mg/kg, ME significantly protected mice against castor oil-induced diarrhoea as well as the number of faeces and wet faeces. Interestingly, administration of ME significantly accelerated GIT in normal mice and reduced stimulated GIT induced by neostigmine. ME also dose-dependently attenuated spontaneous contractions of the isolated rabbit jejunum, and those induced by acetylcholine (Ach) and neostigmine. Moreover, oral administration of ME up to 5g/kg did not produce any toxic effects. Taken together, ME is able to inhibit diarrhoea, increase normal GIT, and decrease GIT induced by neostigmine, which indicate that ME might play a bidirectional role in GI tract. Conclusions: Our study provides a scientific basis for the clinical use of WCAW. [Copyright &y& Elsevier]

Abstract: Immunogenic peptide-based vaccines can raise significant cellular immune responses. Although cytotoxic T lymphocytes (CTL) peptide epitopes are generally poor immunogens, heat shock protein 70 from Mycobacterium tuberculosis (TBhsp70) can overcome this problem since it is a potent adjuvant that links innate and adaptive immune responses. Our goal is to use TBhsp70 as an adjuvant for development of therapeutic vaccines for chronic Hepatitis B virus infection (HBV). To this end, we genetically fused the HBV core 18–27 peptide (HBcAg(18–27)) as a CTL epitope to the C-terminus of TBhsp70 and expressed the resulting protein in methylotropic yeast Pichia pastoris GS115. At the same time, the TBhsp70-HBcAg(18–27) peptide complex was reconstituted in vitro. We investigated whether TBhsp70–peptide complex and TBhsp70–peptide fusion protein could generate antigen specific CTL responses in vitro. Dendritic cells (DC) from HLA-A2+ chronic HBV infection and healthy control pulsed with two vaccines were studied phenotypically by FACS analyses and functionally by cytokine release, and HBV-specific CTL response. Our results demonstrate that two vaccines can activate DC of chronic HBV infection and healthy control by upregulation CD40 and CD86, high production of IL-12p70 and TNF-α. Furthermore, autologous T cells with DC stimulated by two vaccines can produce IFN-γ and generate HBV-specific CTL response. However, capacity for CTL response and cytokines production from HBV infections remained inferior to that of healthy controls. Thus, the strategy of utilizing TBhsp70 may provide a novel design for the development of prophylactic and therapeutic vaccines. [Copyright &y& Elsevier]

We studied the effectiveness of two algorithms, of cross-correlation coefficient and of absolute difference in the case of extended, low-contrast objects, such as solar granulation and sunspots. Wave-front overall tilt signals, acquired via post-processing of sampled solar granulation and sunspot images, are presented. Furthermore, long-exposure images of solar granulation before and after the tilt elimination are compared as regards rms contrast. [Copyright &y& Elsevier]

Candida albicans has the ability to switch reversibly between budding yeast, filamentous, pseudohypha, and hyphal forms, a process in which the transcription factor Flo8 plays an important role. This ability is important for the virulence and pathogenicity of C. albicans. To determine whether Flo8 plays a role in the regulation of drug sensitivity, we constructed a FLO8 null mutant flo8/flo8 from the parental strain SN152 and a Flo8-overexpressing strain, flo8/flo8 :: FLO8. The susceptibility of the isolates to antifungal agents was then evaluated using the agar dilution and broth microdilution methods. Expression of drug resistance-related genes by the isolates was investigated by real-time PCR. The flo8/flo8 mutation isolates exhibited increased resistance to fluconazole, voriconazole, and itraconazole compared with the wild-type and drug sensitivity was restored by FLO8 overexpression (flo8/flo8∷FLO8). Of seven drug resistance-related genes, the FLO8 null mutation resulted in increased CDR1 and CDR2 expression (1.60-fold and 5.27-fold, respectively) compared with SN152, while FLO8 overexpression resulted in decreased CDR1 expression (0.63-fold). These results suggest that Flo8 is involved in the susceptibility of C. albicans to antifungal azoles, with FLO8 deletion leading to constitutive overexpression of CDR1 and CDR2 and resistance to antifungal azoles. [ABSTRACT FROM AUTHOR]

Although numerous studies suggest that organic amendments are better at maintaining soil fertility and crop production than mineral-only fertilization, it is unclear if this occurs in different agricultural systems on a global scale. Here we report a comprehensive meta-analysis of 690 independent experiments comparing the performance of organic amendments and mineral-only fertilization on crop yields, the soil organic carbon (SOC) and total nitrogen (TN) contents, soil nutrient dynamics and biological properties. Our analysis shows that organic amendments increased crop yields on average of 27% than mineral-only fertilization. Farmyard manure (FYM) had the highest effect (49% increase) and this was especially clear in wheat croplands (40% increase). Organic amendment increased the amount of SOC (38%), TN (20%), microbial biomass carbon (MBC; 51%) and microbial biomass nitrogen (MBN; 24%) than mineral-only fertilization. Organic amendments also increased the soil microbiome enzyme activity in terms of soil hydrolytic C acquisition (C-acq; 39%), N acquisition (N-acq; 22%), P acquisition (P-acq; 48%) and oxidative decomposition (OX; 58%). Increased nutrient acquisition and oxidative decomposition could explain the positive effects of organic amendment on crop yields. These observed patterns were consistent for most organic amendments and cropping systems in diverse regions of the world. In summary, our analysis suggests that organic amendments can improve microbe-mediated soil ecosystem functioning, long-term soil fertility and crop productivity, relative to mineral fertilization, on a global scale. [ABSTRACT FROM AUTHOR]

Redox-associated events are important in plant development and responses to environmental stresses. In this study, we investigated spatial redox responses of cucumber ( Cucumis sativus L.) leaves to biotic stress ( Fusarium infection) or abiotic stress (water stress). Plants were grown under hydroponic conditions and either treated with polyethylene glycol to simulate drought or infected with Fusarium oxysporum f. sp. cucumerinum. Both water stress and Fusarium infection restricted cucumber growth and were associated with cellular plasma-membrane damage, reactive oxygen species accumulation, and changes in antioxidants; however, the responses to each stress were distinctive. Under water stress, H 2 O 2 generation at the leaf edge increased 29.7% compared with that at the centre but with Fusarium infection there was a relative 10.4% decrease at the edge. These changes correlated with changes in antioxidants and linked enzyme activities. The key sources of variation in oxidative events were defined by principal component analysis of all of the data and redox balance evaluations. We suggest that these spatial differences under water stress and Fusarium infection arise from discrete regulatory mechanisms, reflecting either developmental effect over the leaf regions or systemic anti-oxidative events occurred following infection. [ABSTRACT FROM AUTHOR]

Soil fungi play key roles in agricultural ecosystem. Yet, little is currently known about the dynamic pattern and driving factors of the rare and abundant fungal subcommunities in response to the short- and long-term continuous cropping. Here, we comparatively investigated the diversity and structure of rare and abundant fungal subcommunities with varying histories of continuous chrysanthemum (Chrysanthemum morifolium Ramat.) cropping, that is, cropping for 1 year (CP1), 6 years (CP6) and 12 years (CP12). The alpha diversity (estimated as Shannon index) of abundant and especially rare fungal subcommunities increased with continuous cropping years. The structure of both rare and abundant subcommunities varied notably with the increasing of continuous cropping years, but the value of dissimilarity for rare taxa (average of 0.988) was significantly higher than for abundant taxa (average of 0.243). The abundant taxon Mortierellomycota and rare taxa Nitrospirae and Elusimicrobia were significantly enriched in the CP12 treatment. Soil rare fungal taxa were mainly affected by the available nutrients (i.e., carbon, nitrogen and phosphorus) and pH, while the abundant fungal taxa were majorly influenced by soil total nutrients. The growth indicators (e.g., plant biomass, plant height, and flower diameter) of cut chrysanthemum significantly decreased under 12-year continuous cropping system. Random forest models showed that abundant rather than rare fungi played key roles in the chrysanthemum growth even though the rare fungi were more significantly affected during continuous cropping. [ABSTRACT FROM AUTHOR]

In continuously cropped fields, residues from decomposing watermelon plants are a primary source of autotoxins, which can inhibit watermelon growth and facilitate invasion of soil-borne pathogens. The composition of the autotoxins produced and the primary microbial decomposers remain unknown. Therefore, a microcosm experiment was conducted to identify the produced volatile organic compounds (VOCs, majority of which are believed to act as autotoxins) as well as the bacteria decomposers of watermelon residue decomposition in Fusarium -infested soil at 7, 14, 30 and 45 days post-inoculation (dpi) by gas chromatography–mass spectrometry (GC–MS) and 13 C-DNA stable isotope probing-denaturing gradient gel electrophoresis ( 13 C-DNA-SIP-DGGE), respectively. Our results indicate that at the beginning of decomposition, there was an increase in the formation of complex phenolic, alcoholic and ester compounds (e.g., 2,6-Bis(1,1-dimethylethyl)-4-(1-oxopropyl)phenol), whereas at 45 dpi, the VOCs were alkenes and alkanes (e.g., dodecane, caryophyllene, pentadecane) with simple structures. The residue-C assimilating community was dominated by the Phyla Alphaproteobacteria , Betaproteobacteria and Firmicutes at 7 dpi. From 14 to 45 dpi, Gammaproteobacteria together with Alphaproteobacteria became dominant. In total, there were 27 bacterial species from 9 phyla that utilized the 13 C-residues in the microcosms. Although the VOC profiles and bacterial decomposers might vary from soils and conditions, these results increase our understanding of residue decomposition of autotoxins and may contribute to mitigate soil-borne disease via crop residue management in field practice. [ABSTRACT FROM AUTHOR]

Nitrogen is a macronutrient which plays an important role in the net primary productivity of terrestrial ecosystems, and is critical to understand how nitrogen addition affects above- and below-ground organisms. However, direct and indirect interactions between microbial species response to nitrogen addition for wheat growth are still unclear. In this study, arbuscular mycorrhizal fungi (AMF) and diazotrophs ( nifH gene) were selected as two groups of key functional microbes in wheat soil to investigate the comprehensive impact of diversity and community structures between them on wheat yield under a nitrogen gradient. Nitrogen addition resulted in a significant shift in AMF and nifH phylogenetic diversity and community structure. The interactions among AMF and nifH species were diminished in high N-treated soils compared to those in low N-treated soils. Structural equation model analysis showed that AMF community structure affected wheat yield directly, however, which was influenced by AMF diversity, diazotrophic diversity and community structure indirectly. The comprehensive effects of AMF and diazotrophs on wheat productivity indicated the importance of soil functional microbes as drivers for farmland ecosystem and plant growth. These results could be useful in understanding soil nutrient cycling and may help improve the mechanistic understanding of the tripartite interaction among nitrogen addition, microbes and wheat productivity. [ABSTRACT FROM AUTHOR]

Even though organic fertilization is known to promote soil nitrogen cycling ( N -cycling), it is unclear how this effect is mediated. Here we studied the potential roles of soil physiochemical properties and soil particle-size fraction (PSF) in relation to the diversity and abundance of N -cycling-related prokaryotes by sampling field sites that had been subjected to either mineral or organic fertilization for over 30 years (two independent fields subjected to both fertilization treatments). We found that organic fertilization increased the 63–200 μm sized soil fraction and the abundance of various N -cycling-related prokaryotes including diazotrophs, ammonia-oxidizers and denitrifiers. Moreover, increase in the abundance of different N -cycling-related prokaryotes varied between different size fractions: the abundance of ammonia-oxidizers and nitrate-reducers was the highest in the 63–200 μm size fraction, while the abundance of diazotrophs, ammonifiers and denitrifiers was the highest in the 200–2000 μm, 2–63 μm and 0.1–2 μm size fractions, respectively. According to structural equation modelling (SEM), soil PSF, physiochemical properties and the community structure of N -cycling-related prokaryotes within different PSFs were associated with the abundance of N -cycling-related prokaryotes in non-fractionated bulk soils. In conclusion, these results suggest that organic, but not mineral, fertilization can support the abundance of N -cycling-related prokaryotes and that the strength of the effects depends on their association with specific particle-size fractions. [ABSTRACT FROM AUTHOR]

The complexity of soil processes involved in the production, consumption and accumulation of volatile organic compounds (VOCs) makes hard to access the overall dynamics of VOCs in the soil. In this study, the field soil, applied with inorganic (CF), organic (OF) and inorganic-organic mixed (CFOF) fertilizers for ten years was evaluated for the emission of VOCs at different temperature and moisture levels. We identified 30–50 soil emitted VOCs representing the most common soil VOCs groups by using the solid-phase microextraction (SPME) fiber and gas chromatography-mass spectroscopy. The highest total emission of VOCs was found in OF treatment, but it was non-significantly different with CF treatment. The emission of VOCs was significantly increased with the decrease in moisture contents and increase in the temperature of the soil. Among different fertilizer treatments, the emission of VOCs was significantly higher in OF treatment at 5% moisture, and in CF and OF treatments at 35 °C. Further, the VOCs emitted from soil treated with CFOF showed the highest increase in plant growth while CF and OF treatments showed similar results. The VOCs were also extracted from the soil using methanol to better understand the dynamics of VOCs. The abundance of VOCs extracted from the soil was 44–61%, while the richness was 65–70% higher than the VOCs emitted from the soil in different treatments. Taken together the results of emitted and extracted VOCs from the soil, we conclude that the fertilizers are able to discriminate among the VOC patterns of soil. In addition, most of the VOCs are retained in the soil and the emission of VOCs from soil depends on the type of VOCs, soil properties and environmental conditions; however, more research is required to find out better soil VOCs analysis methods. [ABSTRACT FROM AUTHOR]

Nitrogen (N) supply significantly influences plant growth and crop yields. To investigate the dynamic process of wheat plant responses to nitrogen management, digital infrared thermography was used to detect canopy average temperature (CAT) during different wheat growth stages in three field management experiments, including N applied rates, N application methods and cultivation approaches, which were conducted in 2013–2014 in southeast China. The CAT was reduced with increased N rates, compared to the control (0 N), applications of 300 kg N ha −1 reduced CAT by 14.0%, 10.7% and 9.2% at the tillering, heading and milking stages, respectively. The CAT was also sensitive to N application methods, in which the CAT of the farmers’ fertilizer practice (FFP) was lower and higher than that of the optimal N management (OPT) before the heading stage and after the heading stage, respectively. Considering the cultivation approaches, the effects of deep tillage (NC-DP) on the CAT was more efficient than normal cultivation (NC) in wheat production. Lower CAT was observed for higher wheat biomass and yield, as a result of the CAT being somewhat negatively correlated with leaf N content. The wheat yield could be estimated by monitoring the CAT based on the response curves of the grain yield and CAT to the N addition rate, which was associated with stomatal conductance and transpiration rate. In conclusion, our results indicated that canopy temperature may provide an effective tool for dynamical monitoring of wheat growth and yields. [ABSTRACT FROM AUTHOR]