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Soil organic carbon (SOC) persistence is predominantly governed by mineral protection, consequently, soil mineral-associated (MAOC) and particulate organic carbon (POC) turnovers have different impacts on the vulnerability of SOC to climate change. Here, we generate the global MAOC and POC maps using 8341 observations and then infer the turnover times of MAOC and POC by a data-model integration approach. Global MAOC and POC storages are 975 964 987 Pg C (mean with 5% and 95% quantiles) and 330 323 337 Pg C, while global mean MAOC and POC turnover times are 129 45 383 yr and 23 5 82 yr in the top meter, respectively. Climate warming-induced acceleration of MAOC and POC decomposition is greater in subsoil than that in topsoil. Overall, the global atlas of MAOC and POC turnover, together with the global distributions of MAOC and POC stocks, provide a benchmark for Earth system models to diagnose SOC-climate change feedback. Separating soil organic carbon into mineral-associated and particulate organic carbon enables a more accurate prediction of soil vulnerability to climate change. The authors generate the global atlas of stocks and turnover times of these two fractions. [ABSTRACT FROM AUTHOR]

Bacteria play an important role in regulating carbon (C), nitrogen (N), and sulfur (S) in estuarine intertidal wetlands. To gain insights into the ecological and metabolic modes possessed by bacteria in estuarine intertidal wetlands, a total of 78 surface soil samples were collected from China's coastal intertidal wetlands to examine the spatial and seasonal variations of bacterial taxonomic composition, assembly processes, and ecological system functions through shotgun metagenomic and 16S rRNA gene sequencing. Obvious spatiotemporal dynamic patterns in the bacterial community structure were identified, with more pronounced seasonal rather than spatial variations. Dispersion limitation was observed to act as a critical factor affecting community assembly, explaining approximately half of the total variation in the bacterial community. Functional bacterial community structure exhibited a more significant latitudinal change than seasonal variability, highlighting that functional stability of the bacterial communities differed with their taxonomic variability. Identification of biogeochemically related links between C, N, and S cycles in the soils showed the adaptive routed metabolism of the bacterial communities and the strong interactions between coupled metabolic pathways. Our study broadens the insights into the taxonomic and functional profiles of bacteria in China's estuarine intertidal soils and helps us understand the effects exerted by environmental factors on the ecological health and microbial diversity of estuarine intertidal flats. [ABSTRACT FROM AUTHOR]

Purpose: The root-associated microbiota is essential to plant health, fitness and productivity, but the effect of plant domestication on the ecological process of microbial community assembly is unclear. Methods: High-throughput sequencing of the 16S rRNA genes was employed to investigated the the diversity, ecological assembly process and cooccurrence relationship of the bacterial communities of multiple root compartment niches (root zone, rhizosphere, and root endosphere) between wild and landrace accessions grown in three soil types. Results: Our results showed that the domestication effect on bacterial community increased from the root zone to the rhizosphere and endosphere, while the soil type effect decreased. Compared with wild soybean, the root endosphere bacterial community of the landraces was more sensitive to soil environmental change. The deterministic process dominated the assembly of the bacterial community in the rhizosphere and root endosphere, and its relative contribution was higher in the landraces than in wild soybeans. In the two root compartments, the increased root system selection pressure in the landraces was indicated by a greater loss of bacteria at the same taxon level and lower bacterial diversity. Furthermore, the family Oxalobacteraceae and the class Actinobacteria were identified as important root-associated biomarker taxa for wild soybeans, while Enterobacteriaceae was such for the landraces. Conclusions: Our findings provide crucial empirical evidence for the host selection and enrichment process of the microbial community under local domestication and are of great significance in understanding the coevolution of hosts and microbiota, which will aid in manipulating microbiota for future crop breeding. [ABSTRACT FROM AUTHOR]

Background: Leguminous crops could fix atmospheric nitrogen through their symbiotic and non-symbiotic associations with different microbes to survive and maintain nutrient in soils that are deficient in nitrogen. Only limited number of lateral roots of the legume prefers to formulate nodules. So far, it is unclear whether microbial communities in lateral roots with/without nodules are different, and whether the selection of microbiome among different types of lateral roots of a plant is a random process or is strictly controlled by the host plant. Methods: We investigated the diversity and community structure of prokaryotic and eukaryotic microorganisms inhabiting in lateral roots with and without nodules of soybean via high-throughput 16S rDNA and 18S rDNA amplicon sequencing. In addition, quantitative microbial element cycling method was applied to estimate the functional genes that are related to carbon, nitrogen, phosphorus, sulfur cycling and methane metabolism. Results: Microbiome in rhizosphere of lateral roots with nodules had significantly lower α-diversity and higher co-occurrence network complexity, compared to those of lateral roots without nodules. The neutral model analysis demonstrated that microbial community of lateral roots with nodules in rhizosphere soil were less affected by neutral process than that of lateral roots without nodules. In addition, we identified a keystone ecological cluster (Module #1) of the rhizosphere cross-kingdom network that positively correlated with multiple functional gene copies, suggesting that the microbial taxa in Module #1 could play important roles in nutrient cycling of rhizosphere microenvironment. Conclusions: Overall, our study revealed the differences in microbial communities in the lateral roots with/without the nodule of root systems and identified a keystone ecological cluster positively linking with multiple functional cycling. [ABSTRACT FROM AUTHOR]

Aims: Licorice (Glycyrrhiza uralensis Fisch.) is a crucial medicinal herb as it accumulates glycyrrhizin and liquiritin in roots. Licorice root-associated bacterial communities shaped by soil characteristics are supposed to regulate the accumulation of root secondary metabolites. Methods: The soil characteristics, root secondary metabolites, and root-associated bacterial communities were analyzed in licorice plants of different ages to explore their temporal dynamics and interaction mechanisms. Results: Temporal variation in soil characteristics and root secondary metabolites was distinct. The alpha-diversity of root-associated bacterial communities decreased with root proximity, and the community composition was clustered in the rhizosphere. Different taxa that were core-enriched from the dominant taxa in the bulk soil, rhizosphere soil, and root endosphere displayed varied time–decay relationships. Soil total potassium (TK) as a key factor regulated the temporal variation in some individual taxa in the bulk and rhizosphere soils; these taxa were associated with the adjustment of root secondary metabolites across different TK levels. Conclusions: Licorice specifically selects root-associated core bacteria over the course of plant development, and TK is correlated with root secondary metabolites and individual core-enriched taxa in the bulk and rhizosphere soils, which may have implications for practical licorice cultivation. [ABSTRACT FROM AUTHOR]

Background: Menopausal hormone therapy (MHT) use has been consistently associated with a decreased risk of colorectal cancer (CRC) in women. Our aim was to use a genome-wide gene-environment interaction analysis to identify genetic modifiers of CRC risk associated with use of MHT.Methods: We included 10 835 postmenopausal women (5419 cases and 5416 controls) from 10 studies. We evaluated use of any MHT, oestrogen-only (E-only) and combined oestrogen-progestogen (E+P) hormone preparations. To test for multiplicative interactions, we applied the empirical Bayes (EB) test as well as the Wald test in conventional case-control logistic regression as primary tests. The Cocktail test was used as secondary test.Results: The EB test identified a significant interaction between rs964293 at 20q13.2/CYP24A1 and E+P (interaction OR (95% CIs)=0.61 (0.52-0.72), P=4.8 × 10(-9)). The secondary analysis also identified this interaction (Cocktail test OR=0.64 (0.52-0.78), P=1.2 × 10(-5) (alpha threshold=3.1 × 10(-4)). The ORs for association between E+P and CRC risk by rs964293 genotype were as follows: C/C, 0.96 (0.61-1.50); A/C, 0.61 (0.39-0.95) and A/A, 0.40 (0.22-0.73), respectively.Conclusions: Our results indicate that rs964293 modifies the association between E+P and CRC risk. The variant is located near CYP24A1, which encodes an enzyme involved in vitamin D metabolism. This novel finding offers additional insight into downstream pathways of CRC etiopathogenesis. [ABSTRACT FROM AUTHOR]

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper. [ABSTRACT FROM AUTHOR]

Agrilus mali (Coleoptera: Buprestidae) is an invasive wood borer pest that has caused considerable damage to the Xinjiang wild fruit forest. In this study, we investigated the bacterial and fungal intestinal microbial communities of A. mali during different developmental stages, including larvae, pupae and newly eclosed adults or fed different diets (leaves of Malus halliana and Malus pumila) using Illumina MiSeq high-throughput sequencing technology. The results showed that microbial alpha diversity first increased and then decreased during the developmental stages, with the most dominant bacteria and fungi exhibiting the dynamic patterns “Decrease”, “Increase” and “Fluctuation”. With respect to the different diets, the bacterial communities were similar between the newly eclosed adults and adults fed M. pumila leaves, while the structure of the fungal communities showed great differences between newly eclosed adults and adults fed different diets. Through a co-correlation network analysis, we observed complex microbial interactions among bacterial and fungal taxa that were associated with potential diverse functions and intricate biological processes in the intestinal microbiota of A. mali. Overall, the results of this study demonstrated that the invasive insect A. mali harbours diverse, dynamic, and presumably multifunctional microbial communities, an understanding of which could improve our ability to develop more effective management approaches to control A. mali. [ABSTRACT FROM AUTHOR]

Understanding interspecies interactions is essential to predict the response of microbial communities to exogenous perturbation. Herein, rhizospheric and bulk soils were collected from five developmental stages of soybean, which grew in soils receiving 16-year nitrogen inputs. Bacterial communities and functional profiles were examined using high-throughput sequencing and quantitative PCR, respectively. The objective of this study was to identify the key bacterial interactions that influenced community dynamics and functions. We found that the stages of soybean development outcompeted nitrogen fertilization management in shaping bacterial community structure, while fertilization treatments significantly shaped the abundance distribution of nitrogen functional genes. Temporal variations in bacterial abundances increased in bulk soils, especially at the stage of soybean branching, which helps to infer underlying negative interspecies interactions. Members of Cyanobacteria and Actinobacteria actively engaged in inter-phylum negative interactions in bulk soils and soybean rhizosphere, respectively. Furthermore, the negative interactions between nitrogen-fixing functional groups and the reduction of nifH gene abundance were coupled during soybean development, which may help to explain the linkages between population dynamics and functions. Overall, these findings highlight the importance of inter-phylum negative interactions in shaping the correlation patterns of bacterial communities and in determining soil functional potential., (© 2021. The Author(s).)