DNA Damage Promotes TMPRSS2-ERG Oncoprotein Destruction and Prostate Cancer Suppression via Signaling Converged by GSK3ß and WEE1.

TMPRSS2-ERG gene fusion occurs in approximately 50% of cases of prostate cancer (PCa), and the fusion product is a key driver of prostate oncogenesis. However, how to leverage cellular signaling to ablate TMPRSS2-ERG oncoprotein for PCa treatment remains elusive. Here, we demonstrate that DNA damage induces proteasomal degradation of wild-type ERG and TMPRSS2-ERG oncoprotein through ERG threonine-187 and tyrosine-190 phosphorylation mediated by GSK3ß and WEE1, respectively. The dual phosphorylation triggers ERG recognition and degradation by the E3 ubiquitin ligase FBW7 in a manner independent of a canonical degron. DNA damage-induced TMPRSS2-ERG degradation was abolished by cancer-associated PTEN deletion or GSK3ß inactivation. Blockade of DNA damage-induced TMPRSS2-ERG oncoprotein degradation causes chemotherapy-resistant growth of fusion-positive PCa cells in culture and in mice. Our findings uncover a previously unrecognized TMPRSS2-ERG protein destruction mechanism and demonstrate that intact PTEN and GSK3ß signaling are essential for effective targeting of ERG protein by genotoxic therapeutics in fusion-positive PCa.

Active antibiotic resistome in soils unraveled by single-cell isotope probing and targeted metagenomics.

Antimicrobial resistance (AMR) in soils represents a serious risk to human health through the food chain and human-nature contact. However, the active antibiotic-resistant bacteria (ARB) residing in soils that primarily drive AMR dissemination are poorly explored. Here, single-cell Raman-D2O coupled with targeted metagenomics is developed as a culture-independent approach to phenotypically and genotypically profiling active ARB against clinical antibiotics in a wide range of soils. This method quantifies the prevalence (contamination degree) and activity (spread potential) of soil ARB and reveals a clear elevation with increasing anthropogenic activities such as farming and the creation of pollution, thereby constituting a factor that is critical for the assessment of AMR risks. Further targeted sorting and metagenomic sequencing of the most active soil ARB uncover several uncultured genera and a pathogenic strain. Furthermore, the underlying resistance genes, virulence factor genes, and associated mobile genetic elements (including plasmids, insertion sequences, and prophages) are fully deciphered at the single-cell level. This study advances our understanding of the soil active AMR repertoire by linking the resistant phenome to the genome. It will aid in the risk assessment of environmental AMR and guide the combat under the One Health framework.

Integrating Multiple Bacterial Phenotypes and Bayesian Network for Analyzing Health Risks of Pathogens in Plastisphere.

Plastic pollution represents a critical threat to soil ecosystems and even humans, as plastics can serve as a habitat for breeding and refuging pathogenic microorganisms against stresses. However, evaluating the health risk of plastispheres is difficult due to the lack of risk factors and quantification model. Here, DNA sequencing, single-cell Raman-D2O labeling, and transformation assay were used to quantify key risk factors of plastisphere, including pathogen abundance, phenotypic resistance to various stresses (antibiotic and pesticide), and ability to acquire antibiotic resistance genes. A Bayesian network model was newly introduced to integrate these three factors and infer their causal relationships. Using this model, the risk of pathogen in the plastisphere is found to be nearly 3 magnitudes higher than that in free-living state. Furthermore, this model exhibits robustness for risk prediction, even in the absence of one factor. Our framework offers a novel and practical approach to assessing the health risk of plastispheres, contributing to the management of plastic-related threats to human health.

Serum IgA as a Prognostic Beacon: Anticipating Systemic Therapy Efficacy in Metastatic Clear Cell Renal Cell Carcinoma.

OBJECTIVE: Immunotherapy-tyrosine kinase inhibitor (IO-TKI) therapy has revolutionized the treatment landscape for metastatic clear cell renal cell carcinoma (mccRCC); however, the absence of effective biomarkers poses a challenge in predicting the efficacy of these regimens. This study aims to explore the predictive and prognostic value of serum immunoglobulin A (IgA) in mccRCC patients undergoing IO-TKI therapy. METHODS: Ninety-six mccRCC patients treated with IO-TKI therapy from 2019 to 2023 were enrolled and serum IgA levels were assessed at the pretreatment baseline and after 3 months of treatment. RESULTS: Notably, baseline levels of IgA showed no correlation with the objective response rate. However, patients achieving complete or partial responses exhibited a remarkable decrease in IgA levels, while those with stable or progressive disease displayed an increase in IgA levels after 3 months of treatment. Furthermore, the dynamic alteration in IgA levels after 3 months of treatment demonstrated predictive value for both progression-free survival (PFS) and overall survival (OS). The time-dependent receiver operating characteristic curves exhibited outstanding performance in predicting PFS (AUC 0.793) and OS (AUC 0.738). CONCLUSION: Taken together, this study demonstrates that dynamic alteration of serum IgA after 3 months of treatment was significantly correlated with prognosis and therapeutic efficacy in mccRCC patients.

Shape-Selective Alkylation of Toluene with Ethanol over a Twin Intergrowth Structured ZSM-5: Modulation of Acidity and Diffusivity via Interface Engineering.

ZSM-5 zeolites with modified acidity and diffusivity are employed as catalysts for the shape-selective alkylation of toluene with ethanol to para-ethyltoluene (p-ET). To avoid pore blocking and loss of active sites caused by traditional methods of enhancing para-selectivity using modifiers, here, we constructed twin intergrowth structured ZSM-5 (Z5-T), achieving modulation of the inherent acidity and diffusivity through interface engineering. The characterization results demonstrate that due to the intergrowth interface, the Z5-T catalyst forms more inherent Lewis acid sites and also renders more sinusoidal channels opened to the surface. Z5-T with an appropriate acidity and enhanced shape-selectivity inhibits side reactions such as isomerization and coke formation, demonstrating improved p-ET selectivity (>90%) and catalytic stability (>200 h) in the alkylation of toluene with ethanol.

Restructuring Surface Lewis Pairs of FAU Zeolite through N Doping for Boosting the Toluene Side-Chain Alkylation Performance.

Toluene side-chain alkylation with methanol for the styrene monomer formation remains a great challenge. An optimal synergy between acidic and basic sites on zeolites is required for an efficient catalysis process. It is important to modulate the surface Lewis acid-base pairs precisely. Herein, we report a strategy to restructure the surface Lewis acid-base pairs in cesium-modified X zeolite (CsX) by N doping. In the process of toluene side-chain alkylation, the CsX-BN-600 catalyst, where N species is doped into the framework of the X zeolite, exhibits 2.7 times the styrene formation rate and a much better selectivity of 85.7% in comparison to the parent CsX of 70.1% selectivity to styrene at the same reaction conditions. The introduction of N species into zeolites acts as a new Lewis base site and optimizes the Lewis sites due to its ability of electron donation. Meanwhile, the frustrated Lewis pair (FLP) between the deprotonated framework nitrogen in X zeolite and positively polarized C species in the side-chain alkylation reaction is created. Furthermore, the N doping contributes to the generation of the active intermediates of HCOO* and H3CO*. These reasons favor the superiority of the catalyst through N doping.

Sewage Sludge Promotes the Accumulation of Antibiotic Resistance Genes in Tomato Xylem.

Xylem serves as a conduit linking soil to the aboveground plant parts and facilitating the upward movement of microbes into leaves and fruits. Despite this potential, the composition of the xylem microbiome and its associated risks, including antibiotic resistance, are understudied. Here, we cultivated tomatoes and analyzed their xylem sap to assess the microbiome and antibiotic resistance profiles following treatment with sewage sludge. Our findings show that xylem microbes primarily originate from soil, albeit with reduced diversity in comparison to those of their soil microbiomes. Using single-cell Raman spectroscopy coupled with D2O labeling, we detected significantly higher metabolic activity in xylem microbes than in rhizosphere soil, with 87% of xylem microbes active compared to just 36% in the soil. Additionally, xylem was pinpointed as a reservoir for antibiotic resistance genes (ARGs), with their abundance being 2.4-6.9 times higher than in rhizosphere soil. Sludge addition dramatically increased the abundance of ARGs in xylem and also increased their mobility and host pathogenicity. Xylem represents a distinct ecological niche for microbes and is a significant reservoir for ARGs. These results could be used to manage the resistome in crops and improve food safety.

Aerobic Anoxygenic Phototrophic Bacteria in the Marine Environments Revealed by Raman/Fluorescence-Guided Single-Cell Sorting and Targeted Metagenomics.

Aerobic anoxygenic phototrophic bacteria (AAPB) contribute profoundly to the global carbon cycle. However, most AAPB in marine environments are uncultured and at low abundance, hampering the recognition of their functions and molecular mechanisms. In this study, we developed a new culture-independent method to identify and sort AAPB using single-cell Raman/fluorescence spectroscopy. Characteristic Raman and fluorescent bands specific to bacteriochlorophyll a (Bchl a) in AAPB were determined by comparing multiple known AAPB with non-AAPB isolates. Using these spectroscopic biomarkers, AAPB in coastal seawater, pelagic seawater, and hydrothermal sediment samples were screened, sorted, and sequenced. 16S rRNA gene analysis and functional gene annotations of sorted cells revealed novel AAPB members and functional genes, including one species belonging to the genus Sphingomonas, two genera affiliated to classes Betaproteobacteria and Gammaproteobacteria, and function genes bchCDIX, pucC2, and pufL related to Bchl a biosynthesis and photosynthetic reaction center assembly. Metagenome-assembled genomes (MAGs) of sorted cells from pelagic seawater and deep-sea hydrothermal sediment belonged to Erythrobacter sanguineus that was considered as an AAPB and genus Sphingomonas, respectively. Moreover, multiple photosynthesis-related genes were annotated in both MAGs, and comparative genomic analysis revealed several exclusive genes involved in amino acid and inorganic ion metabolism and transport. This study employed a new single-cell spectroscopy method to detect AAPB, not only broadening the taxonomic and genetic contents of AAPB in marine environments but also revealing their genetic mechanisms at the single-genomic level.

Long-term seawall barriers lead to the formation of an urban coastal lagoon with increased antibiotic resistome.

Urbanization has increased the spread of antibiotic resistance genes (ARGs) impacting urban aquatic ecosystems and threatening human health. However, an overview of the antibiotic resistome in artificial coastal lagoons formed by coastal seawall construction is unclear. This study investigated the resistome of sediment in a coastal lagoon, established for over 60 years and found that the composition of the resistome in the lagoon sediments associated with the seawall significantly differed from that of marine sediment external to the seawall. Moreover, the diversity, number, relative abundance, and absolute abundance of the antibiotic resistome in the lagoon sediments were significantly higher compared to marine sediment. Network analyses revealed that more co-occurrences were found in lagoon sediment between bacterial communities, ARGs and mobile genetic elements (MGEs) than in marine sediments, suggesting that bacteria in lagoon sediments may be associated with multiple antibiotic resistances. Random forest and structural equation models showed that an increase in the absolute abundance of MGEs had a concomitant effect on the absolute abundance and diversity of ARGs, whereas increasing salinity decreased the absolute abundance of ARGs. This study provides a basis to assess the risk of resistome diffusion and persistence in an artificial coastal lagoon.

P and Se Binary Vacancies and Heterostructures Modulated MoP/MoSe2 Electrocatalysts for Improving Hydrogen Evolution and Coupling Electricity Generation.

It is not enough to develop an ideal hydrogen evolution reaction (HER) electrocatalysts by single strategy. Here, the HER performances are significantly improved by the combined strategies of P and Se binary vacancies and heterostructure engineering, which is rarely explored and remain unclear. As a result, the overpotentials of MoP/MoSe2 -H heterostructures rich in P and Se binary vacancies are 47 and 110 mV at 10 mA cm-2 in 1 m KOH and 0.5 m H2 SO4 electrolytes, respectively. Especially, in 1 m KOH, the overpotential of MoP/MoSe2 -H is very close to commercial Pt/C at the beginning and even better than Pt/C when current density is over 70 mA cm-2 . The strong interactions between MoSe2 and MoP facilitate electrons transfer from P to Se. Thus, MoP/MoSe2 -H possesses more electrochemically active sites and faster charge transfer capability, which are all in favor of high HER activities. Additionally, Zn-H2 O battery with MoP/MoSe2 -H as cathode is fabricated for simultaneous generation of hydrogen and electricity, which displays the maximum power density of up to 28.1 mW cm-2 and stable discharging performance for 125 h. Overall, this work validates a vigorous strategy and provides guidance for the development of efficient HER electrocatalysts.

Targeting SMYD2 inhibits prostate cancer cell growth by regulating c-Myc signaling.

SMYD2 is a lysine histone methyl transferase involved in various cancers epigenetically via methylating histone H3K4, and H3K36. c-Myc is one of the major drivers of prostate cancer (PCa) initiation and progression. The roles of SMYD2 in PCa and the regulators of c-Myc activity in PCa are still under-researched. SMYD2 expression and survival outcomes in PCa cohorts were analyzed by bioinformatics analysis. SMYD2 protein levels were detected in PCa tissues by immunohistochemistry. SMYD2 knockdown cells were established to identify the effects of SMYD2 on cell growth in vitro and in vivo. GSEA and RNA sequencing were adopted to reconnoiter the signaling regulated by SMYD2 in PCa. The relationship between SMYD2 and c-Myc was examined by western blot analysis, qPCR, and immunohistochemistry. SMYD2 specific inhibitor-AZ505 was used to pharmacologically inhibit SMYD2 function in vitro and in vivo. SMYD2 expression increased in PCa tissues compared with benign prostate tissues and higher SMYD2 expression was associated with a higher risk of biochemical relapse after radical prostatectomy. SMYD2 knockdown inhibited the growth of PCa cells both in vitro and in vivo. Furthermore, high SMYD2 levels conduced to activated c-Myc signaling in PCa cells. Importantly, the pharmacological intervention of SMYD2 by AZ505 significantly repressed PCa cell growth both in vitro and in vivo. Our findings indicate that SMYD2 inhibition restrains PCa cell proliferation by regulating c-Myc signaling and provide evidence for the potential practice of SMYD2 targeting in the treatment of PCa.

Increasing Antimicrobial Resistance and Potential Human Bacterial Pathogens in an Invasive Land Snail Driven by Urbanization.

Our understanding of the role urbanization has in augmenting invasive species that carry human bacterial pathogens and antimicrobial resistance (AMR) remains poorly understood. Here, we investigated the gut bacterial communities, antibiotic resistance genes (ARGs) and potential antibiotic-resistant pathogens in giant African snails (Achatina fulica) collected across an urbanization gradient in Xiamen, China (n = 108). There was a lack of correlation between the microbial profiles of giant African snails and the soils of their habitats, and the resistome and human-associated bacteria were significantly higher than those of native snails as well as soils. We observed high diversity (601 ARG subtypes) and abundance (1.5 copies per 16S rRNA gene) of giant African snail gut resistome. Moreover, giant African snails in more urban areas had greater diversity and abundance of high-risk ARGs and potential human bacterial pathogens (e.g., ESKAPE pathogens). We highlight that urbanization significantly impacted the gut microbiomes and resistomes of these invasive snails, indicating that they harbor greater biological contaminants such as ARGs and potential human bacterial pathogens than native snails and soils. This study advances our understanding of the effect of urbanization on human bacterial pathogens and AMR in a problematic invasive snail and should help combat risks associated with invasive species under the One Health framework.

SDF-1-edited human amniotic mesenchymal stem cells stimulate angiogenesis in treating hindlimb ischaemia.

Although stem cells have extensively been studied as a novel vehicle for tissue repair, their sustained efficacy remains controversial. In this study, we aimed to investigate the angiogenic potency over time of stromal cell-derived factor-1 (SDF-1) gene-edited amniotic mesenchymal stem cells (AMM/S) in a hindlimb ischaemia model. An SDF-1 transgene was inserted into the AMM cell genome via transcription activator-like effector nuclease (TALEN) mediated knock-in, and cell migration, Matrigel tube formation, and in vivo Matrigel plug assays were performed. AMM/S were also transplanted into hindlimb ischaemia model mice. Blood perfusion, therapeutic potential, histology, capillary density and in vivo angiogenic assays were performed. AMM/S exhibited high expression of the SDF-1 gene, and robustly promoted migration, proliferation and microvascular formation. AMM/S transplantation significantly increased blood perfusion and limb loss prevention compared with AMM. AMM/S also significantly inhibited increased capillary density and expression of angiogenic factors in the ischaemic hindlimb. Our study demonstrated that AMM/S provides a significant therapeutic effect in ischaemic hindlimbs by enhancing angiogenesis.

Long-Term Fertilization History Alters Effects of Microplastics on Soil Properties, Microbial Communities, and Functions in Diverse Farmland Ecosystem.

Microplastics (MPs) pollution has caused a threat to soil ecosystem diversity and functioning globally. Recently, an increasing number of studies have reported effects of MPs on soil ecosystems. However, these studies mainly focused on soil bacterial communities and a few limited functional genes, which is why MPs effects on soil ecosystems are still not fully understood. Fertilization treatment often coinsides with MPs exposure in practice. Here, we studied effects of an environmentally relevant concentration of polyethylene on soil properties, microbial communities, and functions under different soil types and fertilization history. Our results showed that 0.2% PE MPs exposure could affect soil pH, but this effect varied according to soil type and fertilization history. Long-term fertilization history could alter effects of MPs on soil bacterial and fungal communities in diverse farmland ecosystems (P < 0.05). Soil fungal communities are more sensitive to MPs than bacterial communities under 0.2% PE MPs exposure. MPs exposure has a greater impact on the soil ecosystem with a lower microbial diversity and functional genes abundance and increases the abundance of pathogenic microorganisms. These findings provided an integrated picture to aid our understanding of the impact of MPs on diverse farmland ecosystems with different fertilization histories.

CARD14-associated papulosquamous eruption (CAPE) in a toddler responding to treatment with acitretin.

CARD14-associated papulosquamous eruption (CAPE) is a rare autosomal dominant dermatosis that presents classically in early childhood with clinical features of both psoriasis and pityriasis rubra pilaris (PRP). The disease is known to be refractory to topical and systemic therapies classically used for psoriasis, with the majority of reported cases requiring treatment with biologics, such as ustekinumab and secukinumab. We present a toddler with a clinical presentation consistent with CAPE and found to have a novel heterozygous variant of the CARD14 gene. She was refractory to treatment with topical emollients and topical corticosteroids, but responsive to oral acitretin.

ASC and SVF Cells Synergistically Induce Neovascularization in Ischemic Hindlimb Following Cotransplantation.

Previously, we reported the angio-vasculogenic properties of human stromal vascular fraction (SVF) and adipose tissue-derived mesenchymal stem cells (ASCs). In this study, we investigated whether the combination of ASCs and SVF cells exhibited synergistic angiogenic properties. We conducted quantitative (q)RT-PCR, Matrigel plug, tube formation assays, and in vivo therapeutic assays using an ischemic hind limb mouse model. Immunohistochemical analysis was also conducted. qRT-PCR results revealed that FGF-2 was highly upregulated in ASCs compared with SVF, while PDGF-b and VEGF-A were highly upregulated in SVF. Conditioned medium from mixed cultures of ASCs and SVF (A+S) cells showed higher Matrigel tube formation and endothelial cell proliferation in vitro. A+S cell transplantation into ischemic mouse hind limbs strongly prevented limb loss and augmented blood perfusion compared with SVF cell transplantation. Transplanted A+S cells also showed high capillary density, cell proliferation, angiogenic cytokines, and anti-apoptotic potential in vivo compared with transplanted SVF. Our data indicate that A+S cell transplantation results in synergistic angiogenic therapeutic effects. Accordingly, A+S cell injection could be an alternative therapeutic strategy for treating ischemic diseases.

Phenotypic Tracking of Antibiotic Resistance Spread via Transformation from Environment to Clinic by Reverse D2O Single-Cell Raman Probing.

The rapid spread of antibiotic resistance threatens our fight against bacterial infections. Environments are an abundant reservoir of potentially transferable resistance to pathogens. However, the trajectory of antibiotic resistance genes (ARGs) spreading from environment to clinic and the associated risk remain poorly understood. Here, single-cell Raman spectroscopy combined with reverse D2O labeling (Raman-rD2O) was developed as a sensitive and rapid phenotypic tool to track the spread of plasmid-borne ARGs from soil to clinical bacteria via transformation. Based on the activity of bacteria in assimilating H to substitute prelabeled D under antibiotic treatment, Raman-rD2O sensitively discerned a small minority of phenotypically resistant transformants from a large pool of recipient cells. Its single-cell level detection greatly facilitated the direct calculation of spread efficiency. Raman-rD2O was further employed to study the transfer of complex soil resistant plasmids to pathogenic bacteria. Soil plasmid ARG-dependent transformability against five clinically relevant antibiotics was revealed and used to assess the spreading risk of different soil ARGs, i.e., ampicillin > cefradine and ciprofloxacin > meropenem and vancomycin. The developed single-cell phenotypic method can track the fate and risk of environmental ARGs to pathogenic bacteria and may guide developing new strategies to prevent the spread of high-risk ARGs.

Temporal Dynamics of Antibiotic Resistome in the Plastisphere during Microbial Colonization.

The increasing and simultaneous pollution of plastic debris and antibiotic resistance in aquatic environments makes plastisphere a great health concern. However, the development process of antibiotic resistome in the plastisphere is largely unknown, impeding risk assessment associated with plastics. Here, we profiled the temporal dynamics of antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and microbial composition in the plastisphere from initial microbial colonization to biofilm formation in urban water. A total of 82 ARGs, 12 MGEs, and 63 bacterial pathogens were detected in the plastisphere and categorized as the pioneering, intermediate, and persistent ones. The high number of five MGEs and six ARGs persistently detected in the whole microbial colonization process was regarded as a major concern because of their potential role in disseminating antibiotic resistance. In addition to genomic analysis, D2O-labeled single-cell Raman spectroscopy was employed to interrogate the ecophysiology of plastisphere in a culture-independent way and demonstrated that the plastisphere was inherently more tolerant to antibiotics than bacterioplankton. Finally, by combining persistent MGEs, intensified colonization of pathogenic bacteria, increased tolerance to antibiotic, and potential trophic transfer into a holistic risk analysis, the plastisphere was indicated to constitute a hot spot to acquire and spread antibiotic resistance and impose a long-term risk to ecosystems and human health. These findings provide important insights into the antibiotic resistome and ecological risk of the plastisphere and highlight the necessity for comprehensive surveillance of plastisphere.

Antimicrobial Furancarboxylic Acids from a Penicillium sp.

Ten novel (1, 2, 3a, 3b, 4a, 4b, 5a, 5b, 6a, and 6b) furancarboxylic acids including four pairs of epimers (3a, 3b; 4a, 4b; 5a, 5b; 6a, 6b), together with seven known analogues (7a, 7b, 8a, 8b, 9a, 9b, and 10), were isolated from the fermentation of the soil-derived fungus Penicillium sp. sb62. Their structures were established on the basis of spectroscopic data analysis, and the absolute configurations were determined by time-dependent density functional theory electronic circular dichroism calculations, comparison of the specific optical rotation values, and modified Mosher's method. Compounds 1-4 represent the first class of natural furancarboxylic acids featuring a thiophene moiety. Compounds 1-7 showed antimicrobial inhibitory activities against Escherichia coli, Staphylococcus aureus, and Candida albicans with MIC values ranging from 0.9 to 7.0 µg/mL, from 1.7 to 3.5 µg/mL, and from 3.3 to 7.0 µg/mL, respectively.

D2O-Isotope-Labeling Approach to Probing Phosphate-Solubilizing Bacteria in Complex Soil Communities by Single-Cell Raman Spectroscopy.

Increasing the bioavailability of immobilized phosphorus (P) in soil by phosphate-solubilizing bacteria (PSB) is an effective strategy for sustainable agronomic use of P and for mitigating the P crisis. Here, D2O isotope labeling combined with single-cell Raman spectroscopy (Raman-D2O) was developed as an efficient activity-based approach to characterizing the presence and activity of PSB in a culture-independent way. On the basis of the finding that PSB were significantly more active than non-PSB in the presence of insoluble P, a C-D Raman band from active assimilation of D2O-derived D was established as a biomarker for both inorganic-phosphate-solubilizing bacteria and organic-phosphate-solubilizing bacteria. C-D ratios (intensities of C-D bands as percentages of the intensities of both the C-D and C-H bands) were further established as semiquantitative indicators of P-releasing activities because of the consistency between the C-D ratio and the concentration of solubilized phosphate or acid phosphatase activity as measured by conventional bulk assays. By applying Raman imaging, single-cell Raman-D2O clearly discerned PSB in a mixed-soil bacterial culture and even in complex soil communities. Remarkable heterogeneity of microbial activity, ranging from 2 to 30% (close to that in medium without P and that in medium with sufficient soluble P, respectively), was revealed at the single-cell level and clearly illustrated the subpopulation of soil bacteria active in solubilizing P. This work not only enables probing PSB and their P-releasing activities but also opens a window to explore more diverse microbial resources when obtaining related isotope-labeled substrates is prohibitive.