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Although rice cultivation holds potential for restoring unproductive saline-alkali soils and increasing food production, the mechanisms underlying the relationship between microbial functions and soil element turnover remain unclear. To clarify this relationship, this study investigated the soil physicochemical properties and microbial functions during remediation in saline-alkali soil by rice cultivation over 2, 4, 6, 8, 11, 12, 20, and 23 years. The results indicated rice cultivation markedly improved soil nutrients, soil nutrient stoichiometry, and soil aggregate stability. Additionally, rice cultivation significantly increased the microbial functions involved in nutrient cycling, such as nitrogen fixation, carbon fixation, methanogenesis, dissimilatory sulfate reduction, and thiosulfate oxidation. However, these nitrogen (N), carbon (C), and sulfur (S) cycle-related functions exhibited a similar "increase-peak-decrease" successional pattern with the years of remediation, reaching optimal levels when rice was continuously grown for 11–16 years. Furthermore, correlation analysis demonstrated that the succession of soil microbial N, C, and S functions during saline-alkali soil restoration closely related to changes in soil properties, particularly the availability of phosphorus (P). Therefore, we propose to prioritize the management of P during saline-alkali soil remediation. In conclusion, this study provides a comprehensive understanding of the microbial N, C, and S functions and soil P in the remediation of saline-alkali soils mediated by rice crop. [Display omitted] • Microbial energy metabolism drives rice-mediated remediation of saline-alkali soil. • Microbial N, C, and S functions succession was mainly driven by soil phosphorus. • Rice cultivation for 11–16 years optimally restores saline-alkali soil. [ABSTRACT FROM AUTHOR]

Since Korean red ginseng (KRG) has been proven to protect against gentamicin-induced vestibular and hearing dysfunction, the effects of KRG on age-related inner ear disorder in C57BL/6 mice were investigated. While age-related hearing loss was detected at the age of 6 months (32 kHz) and 9 months (16 kHz) in the control group, it was significantly delayed ( p < 0.05) in the 150 mg/kg KRG-treated group. Vestibular dysfunction was observed in the tail-hanging and swimming tests, with significantly different severity scores and swimming times detected between the control and 150 mg/kg KRG-treated group at the age of 12 months ( p < 0.05). Mice treated with 500 mg/kg KRG exhibited irritability and aggravated inner ear dysfunction. Histological observation supported the findings of hearing and vestibular function defects. In conclusion, C57BL/6 mice showed early-onset hearing loss and progressive vestibular dysfunction with aging, which were delayed by treatment with 150 mg/kg KRG. However, 500 mg/kg KRG treatment may induce aggressive behavior. [ABSTRACT FROM AUTHOR]

The volatile composition of leaves from 14 populations of Hippophae rhamnoides ssp. yunnanensis and H. rhamnoides ssp. sinensis growing in China was analyzed by gas chromatograph–mass spectrometer (GC–MS). Of the 44 compounds represented, 40 were identified. Principal component analysis and cluster analysis were used to investigate the inter-population variability in the composition of volatile compounds. Two main chemotypes were identified, one rich in hexadecanoic acid and eicosanol and the other rich in tetracosane. The hexadecanoic acid and eicosanol-rich chemotype characterizes all seven populations of H. rhamnoides ssp. yunnanensis sampled and the tetracosane-rich chemotype all seven populations of H. rhamnoides ssp. sinensis. [Copyright &y& Elsevier]

Through biological inoculation technology, the joint symbiosis of Tibetan seabuckthorn (Hippophae tibetana) in pure culture was identified and the effects of dual inoculation with Frankia and mycorrhizal fungi on the host plants in pot cultures were investigated. The results obtained from the comparative study showed that H. tibetana could form nodules and VA mycorrhiza both in pot and pure cultures. VA mycorrhizae and Frankia can stimulate the growth and the nitrogen fixation ability of host plants, respectively, yet the stimulation of the dual inoculation on the growth and nitrogen fixation ability of the host plants was more significant (p<0.05): stronger nitrogen-fixing ability, higher VA mycorrhizal development and better growth of seedlings in VAH and HR16 dual inoculation. [Copyright &y& Elsevier]

[Display omitted] • Review of lignin dissociation to provide guidance for the use of lignocellulose. • The advantages and disadvantages of each depolymerization method are summarized. • The contribution made by lignin depolymerization to sugar biorefinery is discussed. The biorefining of sugar-based biomass has attracted increasing attention in response to the continuous depletion of fossil fuel reserves. The key to biorefinery is to choose a suitable way to pretreat lignocellulose to depolymerise lignin, thus releasing cellulose and hemicellulose, and the monosaccharides produced by subsequent enzymatic saccharification can be converted into high value-added compounds by biological or chemical methods, and lignin and its derivatives can also be used in the production of other biopolymers. Currently, numerous scholars have studied and developed processes for lignin depolymerisation. Still, the catalytic depolymerisation of lignin is complex, and the catalytic depolymerisation mechanism and the evolution of the chemical bonding still need to be determined. In this paper, we expect to classify the existing lignin depolymerisation methods and mechanisms reported in the literature and evaluate the advantages and disadvantages of each technique, as well as review the potential applications and challenges of lignin and its derivatives in the production of biopolymers, with the expectation of providing theoretical and technological support for the research and development of new efficient and stable lignin depolymerisation methods, and contributing to the development of biorefinery technology for lignocellulosic resources. [ABSTRACT FROM AUTHOR]

A recent study by Choi et al. provides evidence of the interaction between the karrikin (KAR) signaling and strigolactone (SL) biosynthetic pathways. Since SLs shape rhizomicrobiome composition, it is of interest to determine whether KAR signaling could affect rhizomicrobiome composition by improving the synthesis of root-derived SLs to support climate-smart agriculture. [ABSTRACT FROM AUTHOR]

• Strigolactone (SL) phytohormones determine the rhizomicrobiome in rice. • SL-mediated metabolic pathways are likely to be responsible for the regulation of rhizomicrobiome in rice. • Genetic modulation of rice SL biosynthesis and/or signaling may promote the abundance of specific beneficial bacterial taxa. The rhizomicrobiome helps the host plant to better adapt to environmental stresses. In contrast, plant-derived metabolic substances, including phytohormones, play an active role in structuring rhizomicrobiome. Although strigolactones (SLs), a group of phytohormones, serve as potential rhizosphere signaling molecules, their contributions in shaping the rice (Oryza sativa) rhizomicrobiome remain elusive. To address this issue, we compared the rhizomicrobiome of rice mutants defective in either SL biosynthesis or signaling and wild-type (WT) plants. To understand whether SL-regulated metabolic pathways shape the rhizomicrobiome, a correlation network analysis was conducted among the metabolic pathway-related genes and the rhizomicrobiome of rice. Compared to WT, higher bacterial richness (evidenced by the operational taxonomic unit richness) and lower fungal diversity (evidenced by the Shannon index) were observed in both SL deficient dwarf17 (d17) and signaling (d14) mutants. Additionally, remarkable differences were observed in the composition of a large number of bacterial communities than the fungal communities in the d17 and d14 mutants with respect to the WT. The abundance of certain beneficial bacterial taxa, including Nitrosomonadaceae and Rhodanobacter , were significantly decreased in both mutants relative to the WT. Correlation network analysis between SL-regulated metabolic pathway-associated genes and rhizomicrobiome proposed a role for SL-dependent metabolic pathways in shaping rhizomicrobiome composition. Taken together, our study suggests that SL biosynthesis and signaling play a key role in determining the rice rhizomicrobiome, directly or indirectly, through the mediation of distinct metabolic pathways. Based on our findings, the genetic modulation of rice SL biosynthesis and/or signaling pathways may help to recruit/increase the abundance of the desired rhizomicrobiome, which may assist in the stress resilience of rice. [ABSTRACT FROM AUTHOR]

This study presents evidence that strigolactones (SLs) promote defense against devastating rice blast fungal pathogen Magnaporthe oryzae. Impairment in either SL-biosynthetic dwarf17 (d17) or –signaling (d14) led to increased susceptibility towards M. oryzae. Comparative transcriptome profiling of the SL-signaling d14 mutant and WT plants revealed that a large number of defense-associated genes including hydrogen peroxide (H 2 O 2)-, ethylene- and cell wall-synthesis-related genes were remarkably suppressed in d14 with respect to that of WT plants, during M. oryzae infection. In addition, various KEGG metabolic pathways related to sugar metabolism were significantly suppressed in the d14 plants compared to WT, during M. oryzae infection. Accordingly, WT plants accumulated increased levels of H 2 O 2 and soluble sugar content compared to that of d17 and d14 in response to M. oryzae infection. Altogether, these results propose that SLs positively regulated rice defense against M. oryzae through involvement in the induction of various defense associated genes/pathways. • Strigolactone (SL) synthesis and signaling enhance resistance against rice blast infection. • RNA-sequencing revealed SL-mediated defense-related genes/pathways against blast infection. • SLs may serve as a novel target to improve rice defense against blast infection. [ABSTRACT FROM AUTHOR]

Asian cultivated rice (Oryza sativa L.) domesticated from common wild rice (Oryza rufipogon Griff.) is one of the most consumed staple foods in the world. The rhizomicrobiome plays a vital role in the growth and production of rice. However, the responses of rhizomicrobial community structures to rice cultivation (including agricultural management and rice breeding) and natural environmental shifts are largely unknown. In this study, the rhizomicrobiomes of cultivated rice grown in paddy fields and wild rice grown in natural ecosystems were compared on a regional scale using high-throughput sequencing. For the same location, the cultivated rice showed less selective pressure on the rhizomicrobiome than wild rice. Specifically, compared to the rhizomicrobiome of wild rice, that of cultivated rice had 1) more complicated networks with stronger connections among different groups and 2) higher diversity, as evidenced by the Shannon, Simpson, ACE and Chao1 indices. For different locations, the rhizomicrobiome of cultivated rice was more sensitive to environmental shifts than that of wild rice. Compared to natural ecosystems, in paddy fields, 1) the rhizomicrobial diversity changed more drastically; 2) the number of rhizomicrobial groups cooccurring in different regions was lower at almost all taxonomic levels; and 3) the differences among samples examined by ANOSIM and PERMANOVA tests were more significant. In addition, we observed that the effects of rice cultivation on the rhizomicrobiome were more significant than those of natural environmental shifts on a large scale. Taken together, our results indicate that rice cultivation has profound effects on the rice rhizomicrobiome and that the rhizomicrobiome of cultivated rice in agricultural ecosystems is more sensitive to environmental shifts than that of wild rice in natural ecosystems. [ABSTRACT FROM AUTHOR]

Highlights • Farm manure can increase soil enzymatic activities. • Farm manure can enhance the rhizospheric bacterial abundance and Shannon index. • Bacterial communities correlated with environmental factors and enzymatic activities. • Incorporation of organic manure can improve saline-alkaline soils fertility. Abstract Soil salinization is one of the key factors that threatens plant existence worldwide and is a major challenge to sustain crop production and soil quality. However, there has been limited research on the responses of microbial communities and enzyme activities under soil amendments application in saline alkaline soils. Here, we explored the response of microbial communities and enzyme activities to soil amendments based on 7-year field experiment. The five treatments included FA, amended with farm manure; DE, amended with desulfurization gypsum; SA, amended with sandy soil; M, amended with a mixture of FA, DE and SA; and CK, non-amended control. Relative to the CK treatment, the four amendments, particularly FA, DE and M, significantly decreased the soil pH. Enzyme activities (catalase, urease, alkaline phosphatase and cellulase) were increased in the FA, DE and M treatments, while no difference was observed between SA and CK, except in cellulase. A total of 439,575 effective sequences after filtering out of 1,017,148 raw reads were obtained resulting in 9096 OTUs. Six bacterial phyla of the highest relative abundance were detected including Proteobacteria , Chloroflexi , Bacteroidetes , Actinobacteria , Acidobacteria and Firmicutes across all soil samples (accounting for >85% of the reads). The bacterial community richness was increased in the FA, DE and M treatments, whereas it showed a similar pattern between the CK and SA treatments. Bacterial community diversity was remarkably higher in the M, FA and DE treatments compared to that of CK, while it was reduced in SA. There was a higher similarity in the bacterial communities among DE, FA and M, as well as between CK and SA. Our findings showed that organic manure is a better application approach for the restoration of saline-alkaline soil based on improving the bacterial community and enzyme activities. [ABSTRACT FROM AUTHOR]

Abstract The rhizomicrobiome plays a key role in suppressing soil-borne plant diseases. It remains unclear if crop domestication has altered the rhizomicrobiome and reduced the resistance of domesticated crops to pathogens. To investigate this question, the pathogenic fungus Magnaporthe oryzae was administered to the rhizosphere of plants of cultivated and wild rice to compare the impact of the fungal pathogen on their rhizomicrobiome. The analysis of the results indicated that the presence of M. oryzae affected the community structure and diversity of the rhizomicrobiome of both cultivated and wild rice species. Bacterial and fungal α- and β-diversity of the rhizosphere of cultivated rice were altered more significantly than in wild rice. Furthermore, the abundance of the introduced pathogen was significantly lower in the rhizosphere of wild rice, while the relative abundance of putatively beneficial bacterial and fungal taxa was higher, relative to cultivated rice. These results suggest that the rhizomicrobiome of cultivated rice was more sensitive to the introduction of the fungal pathogen and more easily disturbed than the rhizosphere community of its wild relative. Additionally, a correlation analysis of microbiome and root transcriptome data, obtained under pathogenic and non-pathogenic conditions, indicated that fungal members of the Glomeromycota are important for promoting phenylpropanoid and lignin syntheses in wild rice, which plays a role in resisting M. oryzae infection. The identified differences between the responses of the rhizomicrobiomes of cultivated and wild rice to M. oryzae may provide information that can be used in developing novel strategies to control soil-borne pathogens, which include reconstructing the rhizomicrobiome of domesticated crops to be similar to their wild relatives. Highlights • Rhizomicrobiomes of both cultivated and wild rice are affected by the pathogen Magnaporthe oryzae. • Rhizomicrobiome of cultivated rice is more sensitive to M. oryzae than that of wild rice. • Glomeromycota fungi might play an important role in the resistance of wild rice to M. oryzae. [ABSTRACT FROM AUTHOR]

Chemotaxis is a process that enables motile bacteria to move along nutrient gradients, thereby exploring nutrient hotspots, and potentially playing important biogeochemical roles in agricultural ecosystems. In this study, a 36-year field experiment of nitrogen (N) input was conducted, along with the use of a synthetic community (SynCom) inoculation, to confirm the role of chemotaxis in the cycling of N. The chemotaxis genes abundances of N+ treatments were 97.2% and 95.3% higher than that of N- treatments in bulk soil and rhizosphere, respectively, indicating a significant increase in chemotaxis genes under long-term N input. Positive correlations between chemotaxis genes and N metabolism genes in N+ treatments suggested an important role of chemotaxis in N cycling. The chemotaxis genes abundance was 3.6 times higher in rhizosphere than in bulk soil, and chemotaxis genes showed the most complex correlations with N metabolism genes in rhizosphere under N input, suggesting a key role of chemotaxis in plant N uptake. To assess the potential function of chemotactic bacteria, a SynCom consisting of 10 bacterial strains isolated from in situ N-input soils and capable of chemotaxis, was applied to the maize rhizosphere. The promotion of N acquisition in maize plants through inoculation was confirmed by about 30% greater N content in the shoots of SynCom inoculated soil than in the control. Long-term N input enhanced the functions related to metabolite transport and energy metabolism in the bacterial community, particularly in the rhizosphere. Thus, plants may provide bacteria that migrate to the rhizosphere via chemotaxis with more root metabolites as nutrients. In summary, this study provides novel ecological and molecular insights into chemotaxis-mediated biogeochemical cycling in agricultural ecosystems. • Chemotaxis genes were enriched in rhizosphere under long-term nitrogen input. • Chemotaxis genes were correlated with nitrogen cycling genes. • Specific chemotactic bacteria promoted nitrogen acquisition of maize. [ABSTRACT FROM AUTHOR]

Improving soil carbon sequestration and reducing greenhouse gas emissions in farmland require understanding how the microbial communities that control the agroecosystem function. Here, we surveyed the soil microbial communities in neighboring pairs of dryland and paddy fields in the black soils of northeastern China. Soil moisture, mean weight diameter of aggregates, fluorescence index and biological index of dissolvable organic matter, total anion concentration, and prokaryotic community α-diversity were higher in paddy soils than in dryland soils, while soil saturated hydraulic conductivity (SHC), dissolvable total nitrogen, and fungal community α-diversity were lower in paddy soils than in dryland soils. Moreover, soil moisture (P < 0.01) and SHC (P < 0.05) had significantly positive correlations with the α-diversity of prokaryotic and fungal communities, respectively. The co-occurrence network complexity of microbial communities was lower in paddy fields than in dryland fields, while the co-occurrence network tightness and cooperation of microbial communities were higher in paddy fields than in dryland fields, which may help paddy microbiome resist environmental disturbances. Taken together, both dryland and paddy fields had their own advantages in evaluating soil biological health from microbial community diversity and network stability. Additionally, the differential groups of CH 4 production, S cycle, and Fe cycle (e.g., Bathyarchaeota, Bacteroidetes, and Geobacter) increased, while those of environmental remediation and biological control (e.g., Blastococcus and Roseiflexus) decreased after the change from dryland to paddy fields. Further combined with metagenomic analysis, the functions of CH 4 production, CO 2 fixation, N fixation, and sulfur reduction were enhanced in paddy soils, while those of CH 4 oxidation, nitrification, and N 2 O production were reduced. In conclusion, the ecological functioning of the differential groups may lead to the increase of CH 4 emission and CO 2 fixation, and the decrease of N 2 O emission in paddy fields of black soil, even in non-flooding period. [Display omitted] • The microbial-mediated potential of soil CO 2 fixation was enhanced in paddy soils. • The microbial-mediated potential of soil N fixation was enhanced in paddy soils. • The microbial-mediated potential of soil nitrification was reduced in paddy soils. • The microbial-mediated potential of soil N 2 O production was reduced in paddy soils. • The microbial-mediated potential of soil CH 4 production was enhanced in paddy soils. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cellulose-degrading bacterial and fungal community constitute co-degradation system. • Keystone decomposing fungi are the foundation of co-degradation systems. • Cellulose co-degradation system is controlled by C/N and HA/FA of the composting. To excavate a complex co-degradation system for decomposing cellulose more efficiently, cellulose-degrading bacteria, including Bacillus subtilis WF-8, Bacillus licheniformis WF-11, Bacillus Cereus WS-1 and Streptomyces Nogalater WF-10 were added during maize straw and cattle manure aerobic composting. Bacillus and Streptomyces successfully colonized, which improve cellulose degrading ability. Continuous colonization of cellulose-degrading bacteria can promote the fungi to produce more precursors for humus and promote the negative correlation with Ascomycota. In the current study, the addition of cellulose-degrading bacteria has resulted in the rapid development of Mycothermus and Remersonia in the phylum Ascomycota as keystone fungal genera which constitute the foundation of the co-degradation system. Network analysis reveals the complex co-degradation system of efficient cellulose bacteria and mature fungi to treat cellulose in the process of straw aerobic composting mainly related to the influence of total carbon (TC) /total nitrogen (TN) and humic acid (HA)/fulvic acid (FA). This research offers a complex co-degradation system more efficiently to decompose cellulose aiming to maintain the long-term sustainability of agriculture. [ABSTRACT FROM AUTHOR]

Ethylene is involved in regulation of various aspects of plant growth and development. Physiological and genetic analyses have indicated the existence of crosstalk between ethylene and other phytohormones, including auxin, cytokinin (CK), abscisic acid (ABA), gibberellin (GA), salicylic acid (SA), jasmonic acid (JA), brassinosteroid (BR) and strigolactone (SL) in regulation of different developmental processes. However, the effects of ethylene on the biosynthesis and contents of these hormones are not fully understood. Here, we investigated how overproduction of ethylene may affect the contents of other plant hormones using the ethylene-overproducing mutant ethylene-overproducer 1 ( eto1-1 ). The contents of various hormones and transcript levels of the associated biosynthetic genes in the 10-day-old Arabidopsis eto1-1 mutant and wild-type (WT) plants were determined and compared. Higher levels of CK and ABA, while lower levels of auxin, SA and GA were observed in eto1-1 plants in comparison with WT, which was supported by the up- or down-regulation of their biosynthetic genes. Although we could not quantify the BR and SL contents in Arabidopsis , we observed that the transcript levels of the potential rate-limiting BR and SL biosynthetic genes were increased in the eto1-1 versus WT plants, suggesting that BR and SL levels might be enhanced by ethylene overproduction. JA level was not affected by overproduction of ethylene, which might be explained by unaltered expression level of the proposed rate-limiting JA biosynthetic gene allene oxide synthase . Taken together, our results suggest that ET affects the levels of auxin, CK, ABA, SA and GA, and potentially BR and SL, by influencing the expression of genes involved in the rate-limiting steps of their biosynthesis. [ABSTRACT FROM AUTHOR]

The plants and root-associated microbiomes are closely related. Plant metabolic substances can serve as a nutrient source for the microbiome, and in return, the microbiome can regulate the production of plant metabolic substances. Wild rice ( Oryza rufipogon ), as the ancestor of cultivated rice ( Oryza sativa ), has changed several metabolic pathways and root-associated microbiome during evolution. Thus, the study of the different associations between metabolic pathways and root-associated microbiomes in wild and cultivated rice varieties is important for rice breeding. In this article, the co-evolutionary association between metabolic pathways, which are based on transcriptome data, and root-associated microbiomes, which are based on 16S rRNA and internal transcribed spacer (ITS) amplicon data, in wild and cultivated rice was studied. The results showed that the enriched pathways were differentially correlated with the enriched microbiomes in wild and cultivated rice varieties. Pathways for ‘Glutathione metabolism’, ‘Plant-pathogen interaction’, ‘Protein processing in endoplasmic reticulum’ and ‘Tyrosine metabolism’ were positively associated with the improved relative abundance of bacterial and fungal operational taxonomic units (OTUs) in wild rice. On the other hand, ‘Glycolysis/Gluconeogenesis’, ‘Brassinosteroid biosynthesis’, ‘Carbon metabolism’, ‘Phenylpropanoid biosynthesis’ and ‘Caffeine metabolism’ were positively correlated with the improved relative abundance of bacterial and fungal OTUs in cultivated rice. Redundancy analysis showed that certain bacterial and fungal species could positively and significantly affect plant gene expression; for instance, Streptomyces , with 8.7% relative abundance in bacterial community, significantly affected plant gene expression in wild rice. This study can provide the theoretical basis for recognizing the associations between root-associated microbiomes and root transcriptomes in wild and cultivated rice varieties, and can provide practical significance for developing useful bacterial and fungal resources in wild rice. [ABSTRACT FROM AUTHOR]

Biochar addition to soil can change soil physicochemical properties, resulting in a shift of the soil microbial community. However, it is uncertain how long-term biochar application affects the soil microbial community and diversity in drylands. To determine the underlying mechanism, a 3.5-year spring maize ( Zea mays L.) field experiment with biochar applications was conducted to elucidate the effect of biochar on soil microbial abundance and community composition as well as its potential applications in drylands of the Loess Plateau in Northwest China. Soil samples from a 0–20 cm depth for four biochar treatments, including 0 (C0, as the control), 10 (C10), 30 (C30) and 50 (C50) t ha −1 , were examined using phospholipid fatty acid (PLFA) analysis. It was found that the proportion of arbuscular mycorrhizal fungi (AMF) and the ratio of AMF/saprotrophic fungi (SF) correlated with the biochar levels, for example, the C30 treatment significantly decreased the absolute SF but increased the ratio of AMF/SF. Especially, both the AMF/SF and Fungi/Bacteria ratios were significantly increased in the C50 treatment, suggesting that high amounts of biochar could increase fungal rather than bacterial diversity. In addition, soil organic C (SOC) ( P < 0.01), KMnO 4 -oxidizable C (KMnO 4 -C) ( P < 0.01), and the C management index (CMI) ( P < 0.01) were confirmed to play significant roles in shaping the soil microbial community composition. SOC and total N were significantly increased by biochar application, and total P was increased in the C30 treatment. However, compared with the C0 treatment, the C50 treatment significantly decreased KMnO 4 -C and the CMI, suggesting the proper level of biochar addition to soil should be considered for the improvement of soil organic materials. Accordingly, biochar application at 30 t ha −1 , which was connected with a decreased absolute SF and an increased AMF/SF ratio, could be a choice for improving soil quality and nutrient availability in semiarid farmland. [ABSTRACT FROM AUTHOR]

To understand the impact of wetland cultivation and restoration on soil microbes and the corresponding soil biogeochemical processes, an experiment was established that included three cultivated treatments (marshes with 5, 15, and 25 years (CU05, CU15 and CU25) of soybean cultivation), two restored treatments (with 6 and 12 years (RE06 and RE12) of agricultural abandonment), and a natural marsh (NAT) as a reference. Changes in soil properties and microbial communities across the different treatments were analyzed. The results showed that soil microbial biomass and almost all the measured nutrients decreased in the order of NAT, restored treatments and cultivated treatments. Soil microbial structures in restored treatments were more similar to those of NAT than those of cultivated treatments. Specifically, the soil microbial communities of NAT and restored treatments were distinguished by a higher relative abundance of fungi, which were positively influenced by soil organic carbon and total nitrogen. In contrast, cultivated treatments were characterized by a higher relative abundance of gram-positive bacteria, which were positively influenced by the C/N ratio. The results indicated that the degraded soil in cultivated treatments began to recover after agricultural abandonment. However, the differences in soil microbial structures between restored treatment and NAT soils indicated that 12 years of restoration was not sufficient to restore the cultivated marshes to their natural status. Among all the measured soil properties, soil organic carbon and available potassium were identified as the main drivers of soil microbial communities, while the effect of pH on soil microbes was insignificant in this study. As available phosphorus was significantly decreased in the soil of restored treatments, phosphorus addition might be an effective way to accelerate the restoration process. [ABSTRACT FROM AUTHOR]

[Display omitted] • Lignin with a relatively complete structure was obtained from corn stover. • Using Lac to start enzyme reactions can synergize with LiP and MnP to degrade lignin. • A combination of all three enzymes provided the best percentage degradation. • Acid compounds dominated the products of enzymatic lignin degradation. • Degradative enzymes break key bonds in lignin and open benzene rings. Lignin of high purity and structural integrity was isolated from the enzymatic residue of corn stover. Degradation of the lignin by laccase, lignin peroxidase, and manganese peroxidase was investigated. Structural changes in the lignin after degradation were characterized by scanning electron microscopy, nitrogen adsorption and Fourier transform infrared spectroscopy, and the enzymatic products were systematically analyzed by gas chromatography mass spectrometry. The highest percentage of lignin degradation was obtained with a mixture of three enzymes (25.79%): laccase (Lac), the starting enzyme of the mixed enzyme reaction, worked with lignin peroxidase (LiP), and manganese peroxidase (MnP) to further degrade lignin. This degradation destroyed the macromolecular structure of lignin, broke its key chemical bonds, and opened benzene rings, thus producing more acidic compounds. This study elucidated the concept of degrading lignin from corn stover using the Lac, LiP and MnP enzymes synergistically, thus providing a theoretical basis for the biodegradation of lignin. [ABSTRACT FROM AUTHOR]

[Display omitted] • Exogenous cellulose-degrading bacteria (ECDB) promoted degradation of organic matter. • ECDB increased the content of humus during composting. • ECDB changed bacterial communities and enhanced the interactions among them. • ECDB enhanced the driving force of humus synthesis in composting. This study aimed to reveal the potential mechanism of influence exogenous cellulose-degrading bacteria (ECDB) exerted on humus synthesis during the co-composting of corn straw and cattle manure. By measuring the changes in physicochemical factors and bacterial communities, it was revealed that inoculation with ECDB enhanced the driving force of cellulose degradation and humus synthesis. ECDB not only directly participated in cellulose degradation as degrading bacteria, but also changed the bacterial community succession, and increased the abundance of bacterial communities associated with cellulose degradation. The results showed that ECDB stimulated the potential functions and interactions of bacterial communities. Structural equation modeling confirmed that ECDB acted mainly as a bioactivator to promote humus formation in co-composting of corn straw and cattle manure. Taken together, these findings offered new strategies which can be effectively utilized to increase the efficiency and quality of corn straw composting. [ABSTRACT FROM AUTHOR]

Plastic film mulching (PF) can change soil properties and microbial community structure. However, the effect of PF on soil microbial interactions in different aggregate fractions is still unclear. We conducted a three-year field trial in black soil of northeastern China to evaluate the variation in soil microbial interactions and community structure in different aggregate fractions after PF. Compared with the control (CK), the PF treatment significantly decreased the humification index by 13.9% and chromophoric dissolved organic matter by 36.6% and significantly increased the fractal dimension by 4.8% and electrical conductivity by 22.8%. In addition, the PF treatment significantly decreased the relative abundances of Chloroflexi, Planctomycetes and Verrucomicrobia but significantly increased the relative abundance (RA) of Proteobacteria. Furthermore, the PF treatment significantly decreased the RA of Glomeromycota in megaaggregates (>2 mm, ME) and macroaggregates (0.25–2 mm) and the RA of Actinobacteria in microaggregates (<0.25 mm, MI), related to decreases in aggregate stability. Compared with the CK treatment, the PF treatment significantly decreased the bacterial Shannon index in ME but significantly increased the fungal Shannon index in MI. Moreover, β-1,4-glucosidase activity significantly influenced the community structure of soil bacteria and fungi. The PF treatment decreased soil microbial interactions, especially in ME. The keystone of the microbial network shifted from 0319-6A21 (Nitrospirae) to Gsoil-1167 (Actinobacteria) after PF. In short, PF decreased soil aggregate stability and microbial interactions in black soil in a subhumid area. [Display omitted] • Plastic film mulching (PF) decreased microbial interactions in black soil. • The keystone of microbial network was Gsoil-1167 (Actinobacteria) under PF. • PF significantly decreased the bacterial Shannon index in megaaggregates. • PF significantly increased the fungal Shannon index in microaggregates. • PF significantly decreased soil aggregate stability and the humification of DOM. [ABSTRACT FROM AUTHOR]

Soybean is considered as one of the most important food for both humans and animals; unfortunately, it faces soil-borne diseases caused by bacteria or fungi, leading to severe yield losses. Hybridization has helped the soybean to obtain beneficial genes from wild species that can resist some adverse conditions. However, the influences of hybridization on the rhizosphere microbiomes of wild and cultivated soybeans have not been much elucidated until now. In this article, we investigated the influences of hybridization of wild and cultivated soybeans on the rhizosphere microbiomes using four soybean genotypes: the cultivated soybean (C), the wild soybean (W), the first hybridization generation (F1) and the second hybridization generation (F2). Results indicated that there had significant differences in both the fungal and bacterial communities in all four groups. More specifically, bacterial and fungal communities were more similar between the F2 generation and wild soybean groups. The relative abundances of Glomeromycota in wild soybean and F2 generation were significantly higher than those in C and F1 groups. Furthermore, the network analysis showed that the wild soybean had more complicated bacterial and fungal connections than other genotypes, which might help wild soybean maintain the beneficial traits of resistance to adverse conditions. Results of this study can provide a theoretical basis for recognizing the different members of the rhizosphere bacterial and fungal communities of wild and cultivated soybeans, as well as their offspring. Additionally, our findings will hopefully provide a practical guide for screening useful microbial resources from the wild soybean rhizomicrobiome. • Hybridization of wild and cultivated soybeans influences the structure of rhizosphere microbiomes. • Wild soybean has more complicated bacterial and fungal connections. • The relative abundances of Glomeromycota in the wild soybean and F2 generation were significantly higher than those in the cultivated soybean and F1 generation. [ABSTRACT FROM AUTHOR]

Soil type and domestication are the main factors that contribute to the determination of root-associated bacterial communities in soybean; however, to what extent these factors influence root-associated fungal communities remains unclear. Here, we grew wild soybean (Glycine soja) and cultivated soybean (Glycine max) in three soil suspensions (black, red and saline-sodic soil) and analyzed the soybean rhizosphere fungal internal transcribed spacer 1 (ITS1) region by high-throughput sequencing technology. The results showed that the fungal communities had significantly different richness and alpha-diversity indexes in the three soil suspensions; however, there was no marked difference in the rhizosphere fungal communities between the two wild and cultivated soybean varieties. Furthermore, soil type was a main factor in determining the distribution of arbuscular mycorrhizal fungi (AMF; Paraglomus and Rhizophagus) and soybean pathogenic fungi (Fusarium and Rhizoctonia). In addition, the abundant rhizosphere fungi from wild soybean exhibited diverse potential functions, while the functions of rhizosphere fungi from cultivated soybean were mainly related to plant nutrient uptake. The diversity and structure of the soybean rhizosphere fungal communities were mainly affected by soil type rather than soybean variety, and domestication caused wild and cultivated soybeans to recruit different rhizosphere fungi. Accordingly, a thorough understanding of soybean fungal communities and their influencing factors is important for improving the health and harvest of soybean. • Soil type and wild and cultivated soybean varieties induced rhizosphere fungi shifts. • Soil type had a decisive influence on the distribution of pathogenic fungi and AMF. • More diverse potential functions in wild than cultivated soybean rhizosphere fungi [ABSTRACT FROM AUTHOR]

Continuous cropping of soybean often causes significant declines in yields of soybean because of the outbreaks of soil-borne fungal diseases. It has been reported that wild crops often harbour a unique microbiome to benefit the host plants. Thus, it is necessary to find the different community structures of the rhizomicrobiomes associated with cultivated and wild soybeans in their continuous cropping. In this study, we simulated monocropping of cultivated and wild soybeans under greenhouse conditions to investigate the rhizomicrobiomes of both soybeans. Results indicated that the bacterial community structure still maintained a changing trend after four continuous planting seasons, while fungal community structure showed a stable trend as indicated by the high similarity in the fungal community structure between the third and fourth planting rotations in both soybeans. In addition, by comparing the continuous cropping of the two soybeans, we found different fungal groups in their rhizospheres between the wild and cultivated soybeans following each passage. Spizellomycetaceae was more highly enriched in the rhizosphere following cultivation of the cultivated soybean, while Chaetomiaceae and Orbiliaceae were more highly enriched in the rhizosphere of wild soybean. Taken together, results of this study suggested that although there was the same trend of stabilized fungal development in the rhizospheres of both soybeans, wild soybean rhizosphere had different fungal groups compared with that of cultivated soybean following their continuous cropping. The findings of this study may provide useful information for the farmers with regard to planting soybean, especially when they consider growing soybean in monoculture. [ABSTRACT FROM AUTHOR]