Rhizospheric bacterial communities against microplastics (MPs): Novel ecological strategies based on the niche differentiation.

Considerable amounts of microplastics (MPs) are stocked in plant rhizospheres, yielding adverse effects on rhizospheric microorganisms and threatening plant health. However, the adaptation of the rhizospheric microbiota for MPs remains largely unknown. Here, to evaluate the adaptive strategies of rhizospheric bacterial communities against MPs, we characterized the spatial dissimilarities in MPs properties and bacterial communities from mangrove non-rhizosphere to rhizosphere to root hair sediments. Consequently, two strategies were uncovered: (1) Bacterial communities showed significant niche differentiation induced by the increasingly enriched MPs evaluated by piecewise structural equation modeling (piecewise SEM), as increasing specialization (10.2 % to 19.4 % to 23.0 % of specialists) and decreasing generalization (10.4 % to 10.2 % to 8.7 % of generalists). (2) A self-remediation strategy of enhancing microbial plastic-degrading potentials was determined in bacterial communities, tightly coupled to the increase of specialists (linear regression analysis, R2 = 0.54, P < 0.001) and increasing MPs weathering degrees visualized by the scanning electron microscopy (SEM) from non-rhizosphere to rhizosphere to root hair regions. Our study provides a novel insight into the ecological strategies that rhizospheric microbes utilize against MPs, and broadens our knowledge of the interaction between soil microbes and global MPs pollution.

Fate and drivers of mariculture-derived microplastics from ponds to mangrove forests.

Due to the combined influences of marine and terrestrial disturbances, the sources of microplastics (MPs) in mangrove ecosystems are complex and diverse. Previous studies have inferred the possible involvement of mariculture activities as a potential source of mangrove MPs based on the characteristics of MPs. However, the direct contributions of mariculture-derived MPs to mangrove MPs remain largely unknown. In this study, we systematically investigated the fate of MPs in the discharge of mariculture wastewater by quantifying the source contributions of mariculture-derived MPs to rivers and mangroves. The majority of detected MPs were transparent fibers, with their composition primarily comprising materials commonly used in mariculture activities such as polyvinylpyrrolidone (PVP), polyethylene terephthalate (PET), and nylon. The partial least squares path model elucidated the relationships among the composition of MPs in ponds, rivers, and mangroves, indicating that ponds exert a substantial direct effect on mangroves, particularly significant in the sediments (63.68%). Water turbidity, sediment carbon content, and sediment particle size are key ecological factors influencing the abundance of mariculture-derived MPs. This study provides compelling evidence regarding the sources of mangrove MPs and novel insights into mitigating the dissemination of MPs.

Synergistic action and mechanism of scoparone, a key bioactive component of Artemisia capillaris, and spirodiclofen against spider mites.

BACKGROUND: Plants have numerous defensive secondary metabolites to withstand insect attacks. Scoparone, which is extracted from the medicinal plant Artemisia capillaris, has potent acaricidal effects on Tetranychus cinnabarinus. Spirodiclofen, derived from a tetronic acid derivative, is a potent commercial acaricide that is extensively used globally. However, whether scoparone has synergistic effects when used in conjunction with spirodiclofen and the underlying synergistic mechanism remains unclear. RESULTS: Scoparone exhibited a potent synergistic effect when it was combined with spirodiclofen at a 1:9 ratio. Subsequently, cytochrome P450 monooxygenase (P450) activity, RNA-Seq and qPCR assays indicated that the enzyme activity of P450 and the expression of one P450 gene from T. cinnabarinus, TcCYP388A1, were significantly inhibited by scoparone and spirodiclofen + scoparone; conversely, P450 was activated in spirodiclofen-exposed mites. Importantly, RNAi-mediated silencing of the TcCYP388A1 gene markedly increased the susceptibility of spider mites to spirodiclofen, scoparone and spirodiclofen + scoparone, and in vitro, the recombinant TcCYP388A1 protein could metabolize spirodiclofen. Molecular docking and functional analyses further indicated that R117, which is highly conserved in Arachnoidea species, may be a vital specific binding site for scoparone in the mite TcCYP388A1 protein. This binding site was subsequently confirmed using mutagenesis data, which revealed that this binding site was the sole site selected by scoparone in spider mites over mammalian or fly CYP388A1. CONCLUSIONS: These results indicate that the synergistic effects of scoparone and spirodiclofen on mites occurs through the inhibition of P450 activity, thus reducing spirodiclofen metabolism. The synergistic effect of this potent natural product on the detoxification enzyme-targeted activity of commercial acaricides may offer a sustainable strategy for pest mite resistance management. © 2024 Society of Chemical Industry.

Secreted salt and hydrodynamic factors combine to affect dynamic fluctuations of microplastics on mangrove leaves.

Mangrove leaves have been acknowledged as crucial sink for coastal microplastics (MPs). Whereas, the temporal dynamics of MPs intercepted by mangrove leaves have remained poorly understood. Here, we detected MPs intercepted by submerged and non-submerged mangrove leaves over time and the potential driving factors. Abundance and characteristics of MPs interception by mangrove leaves exhibited dynamic fluctuations, with the coefficient of variation (CV) of submerged mangrove leaves (CV = 0.604; 1.76 n/g to 15.45 n/g) being approximately twofold higher than non-submerged mangrove leaves (CV = 0.377; 0.74 n/g to 3.28 n/g). Partial least squares path model (PLS-PM) analysis further illustrated that MPs abundance on submerged mangrove leaves were negative correlated to hydrodynamic factors (i.e., current velocity and tidal range). Intriguingly, secreted salt as a significantly driver of MPs intercepted by mangrove leaves. Results of this work highlights that MPs intercepted by mangrove leaves is characterized by dynamic fluctuations and reveals the importance of hydrodynamic factors and secreted salt. Overall, this work identifies the pivotal buffering role played by mangrove leaves in intercepting MPs, which provides basic knowledge for better understanding of microplastic pollution status and control from mangrove plants.

Selective enrichments for color microplastics loading of marine lipophilic phycotoxins.

Microplastics (MPs) and marine lipophilic phycotoxins (MLPs) are two classes of emerging contaminants. Together, they may exacerbate the negative impacts on nearshore marine ecosystems. Herein, the loading of 14 representative MLPs, closely related to toxin-producing algae, on MPs and their relations with colorful MPs have been explored for the first time based on both field and lab data. The objectives of our study are to explore the roles of multiple factors (waterborne MLPs and MP characteristics) in the loading of MLPs by MPs with the applications of various statistical means, and to further explore the role of the color of MP in the loading of specific MLPs through lab simulation experiments. Our results demonstrated that MPs color determined the loading of some specific MLPs on MPs and green MPs can load much more than other colorful fractions (p < 0.05). These interesting phenomena illustrated that the color effects on the loading processes of MLPs on MPs are a dynamic process, and it can be well explained by the shading effect of MP color, which may affect the growth and metabolism of the attached toxic-producing algae on MPs and hence the production of specific MLPs. Furthermore, loading of MLPs on MPs can be considered as the comprehensive physicochemical and biological processes. Our results caution us that special attention should be paid to explore the real-time dynamic color shading effects on all kinds of bio-secreted contaminants loading on MPs, and highlight the necessary to comprehensive investigate the interaction between biota, organic contaminants and MPs.

Development and validation of a nomogram for predicting overall survival in cirrhotic patients with acute kidney injury.

BACKGROUND: Acute kidney injury (AKI) is a common and severe complication in patients with cirrhosis, and is associated with poor prognosis. Therefore, identifying cirrhotic patients with AKI who are at high risk of mortality is very important and may be helpful for providing timely medical interventions to improve the prognosis of these patients. However, studies focused on investigating the risk factors for the mortality of cirrhotic patients with AKI were scarce. AIM: To identify risk factors for mortality and establish a nomogram for predicting the prognosis of these patients. METHODS: Two hundred fifty consecutive patients with cirrhosis and AKI were recruited and randomly divided into training cohort (n = 173) and validation cohort (n = 77). In the training cohort, potential risk factors for death were identified by performing a Cox regression analysis, and a nomogram was established. The predictive performance of the nomogram was internally and externally validated by calculating the area under the receiver operating characteristic curve (AUROC), constructing a calibration curve and performing decision curve analysis. RESULTS: The serum sodium level, international normalized ratio, peak serum creatinine level > 1.5 mg/dL, the presence of hepatic encephalopathy and diabetes were potential risk factors for mortality of cirrhotic patients with AKI in the training dataset. A prognostic nomogram incorporating these variables was established for predicting the overall survival of these patients. Compared with Child-Turcotte-Pugh, the model for end-stage liver disease (MELD) and the MELD-Na scores, the nomogram in predicting 90- and 180-d mortality exhibited better discriminatory power with AUROCs of 0.792 and 0.801 for the training dataset and 0.817 and 0.862 for the validation dataset, respectively. With a nomogram score of 98, patients were divided into low- and high-risk groups, and high-risk patients had a higher mortality rate. CONCLUSION: A prognostic nomogram displayed good performance for predicting the overall survival of cirrhotic patients with AKI, and will assist clinicians in evaluating the prognosis of these patients.

Genetic analysis and identification of candidate genes for two spotted-leaf mutants (spl101 and spl102) in rice.

Spotted-leaf mutants form spots in leaves or leaf sheaths under normal condition. The spotted-leaf phenotypes are similar to hypersensitive reaction of plants attacked by pathogen. Identification and characterization of the spotted-leaf mutants are helpful for understanding the mechanisms of resistance to plant diseases. Here, we identify two spotted-leaf mutants spl101 and spl102 from an EMS-treated elite japonica cultivar KYJ (Kuanyejing). spl101 and spl102 form serious spots at the late heading stage. Genetic analyses show that the spotted-leaf phenotypes of both spl101 and spl102 are caused by a single recessive mutation, respectively. By employing the Mutmap method, we reveal that both spl101 and spl102 contain mutations in the OsEDR1 gene. The spl101 mutation occurs in the 5°-splicing site of the 6th intron of OsEDR1, which causes abnormal recognition of the 6th intron and leads to the frameshift mutation. The spl102 mutant contains a mutation in the tenth exon of OsEDR1, resulting in an amino acid change from the phenylalanine (F) to the cysteine (C). OsEDR1 has been reported to regulate pathogen-resistant reaction, and loss of OsEDR1 function produces similar phenotypes to those of spl101 and spl102. Here, two newly identified alleles of OsEDR1 will be benefit for further understanding the molecular mechanisms of the OsEDR1 gene in disease resistance, and will be helpful for enriching the rice germplasm resources. In addition, our results also validate the effectiveness of the Mutmap method in cloning the candidate mutations.

[Genetic analysis and identification of candidate genes for a narrow leaf mutant (zy17) in rice].

Control of organ size by cell proliferation and cell expansion is a fundamental process in plant development, but little is known about the genetic and molecular mechanisms that determine organ size in plants. To understand the genetic and molecular mechanisms of organ growth control, we isolate a set of mutants with altered leaf size and identify the narrow leaf mutant, zhaiye 17 (zy17) (zhaiye means narrow leaf in Chinese). zy17 exhibits narrow leaves, slightly short plants, small panicles, reduced panicle branches and decreased grain numbers per panicle compared with the wild type. Our cytological analyses show that the narrow leaf phenotype of zy17 is caused by the reduced number of cells, indicating that ZY17 regulates cell proliferation. Genetic analyses show that the zy17 mutant phenotypes are controlled by a single gene. Using the whole genome resequencing approach and linkage analysis, we identify Os02g22390, Os02g28280 and Os02g29530 as candidate genes. Os02g22390 encodes a retrotransposon protein with the mutation occurring in the intronic region; Os02g28280 encodes a protein with unknown function with a base substitution resulting in non-synonymous mutation; Os02g29530 encodes a protein containing the PFAM domain related to glycosyltransferase, with a 2 bp deletion mutation causing a premature termination. Further studies on these three candidate genes will be helpful for understanding the molecular mechanism of organ size control in rice.

[Dynamic contrast-enhanced MSCT findings of intraductal papillary neoplasm of the bile ducts].

OBJECTIVE: To investigate the findings of contrast-enhanced multislice computed tomography (MSCT) that characterize intraductal papillary neoplasms of bile ducts (IPNB). METHODS: The MSCT findings and clinical data of 16 cases of IPNB proven by surgical pathology were reviewed retrospectively. RESULTS: Among the 16 cases, nine were adenoma (multi-lesions, n = 5; single lesions, n = 4) and seven were adenocarcinoma (multi-lesions, n = 4; single lesions, n = 3). Among the nine adenoma cases, seven showed nodules or masses in the expanding intrahepatic bile ducts with asymmetrical low density on plain scan, and two showed obvious expansion of biliary ducts and the inner wall of bile ducts was rough. All seven of the adenocarcinoma cases showed nodules or masses in the expanding intrahepatic bile ducts with asymmetrical low density-like adenoma. When contrast enhancement was applied, the nine adenoma cases manifested slight-to-moderate degrees of asymmetrical enhancement. For the seven adenocarcinoma cases, two showed asymmetrical enhancement similar to that of the adenoma cases and five showed continued enhancement; one case showed malignant infiltration of the bile duct and evident damage in the adjacent hepatic tissue. The CT plain scan findings for the two groups (adenoma and adenocarcinoma) were not significantly different (t = -1.17, P = 0.2632). Significantly different findings were obtained with the MSCT imaging analysis for the arterial phase (t = 6.53, P less than 0.01) and the portal vein phase (t = 5.63, P less than 0.01). All cases showed asymmetrical expansion of intrahepatic biliary ducts, diffuse or local, and four cases showed moderate expansion of the common bile duct. One adenocarcinoma case showed intumescence in the celiac lymph node by moderate asymmetrical enhancement. CONCLUSION: MSCT is helpful for the differential diagnosis of IPNB from other hepatic lesions.

miR-495 and miR-551a inhibit the migration and invasion of human gastric cancer cells by directly interacting with PRL-3.

The phosphatase of regenerating liver-3 (PRL-3) gene is associated with metastasis in gastric cancer, and is believed to play a causative role by promoting tumor cell motility, invasion, and metastasis, but little is known of the mechanisms involved. We previously reported that PRL-3 expression is significantly higher in the tissues of primary gastric carcinomas with peritoneal metastasis. In the present study, we found that two microRNAs (miRNAs), miR-495 and miR-551a, predicted to target PRL-3, are downregulated in gastric carcinoma samples. The validation of this interaction between those two miRNAs and PRL-3 was confirmed by western blotting and quantitative real-time PCR (qPCR) in GC cell lines transfected with miR-495 and miR-551a mimics. Furthermore, the migration and invasion of GC cells were significantly inhibited by transfection with miR-495 or -551a mimics, and the mRNA and protein levels of PRL-3 were reduced in cells overexpressing miR-495 or -551a. Collectively, our findings suggest that miR-495 and miR-551a both act as tumor suppressors by targeting the PRL-3 oncogene and inhibiting gastric cancer cell migration and invasion. The findings of this study contribute to current understanding of the functions of miRNA mimics in GC gene therapy.

[Necessity of No.13 lymph node dissection in advanced gastric carcinoma].

OBJECTIVE: To investigate the feasibility and necessity of No.13 lymph node dissection for advanced gastric carcinoma. METHODS: Clinical data of 144 cases who were diagnosed as TNMII-III stage gastric carcinoma were collected from January 2007 to December 2009 in the Department of General Surgery at the First Affiliated Hospital of Nanchang University. Seventy-two cases who received D2 radical gastrectomy plus No.13 lymph node dissection were selected as the study group, and they were matched 1:1 to 72 cases who received D2 Radical gastrectomy (the control group) for TNMII-III stage gastric carcinoma. The differences in the intraoperative and postoperative parameters and survival time were compared, and the factors associated with No.13 lymph node metastasis were analyzed. RESULTS: There were no significant differences between the two groups in operative time [(2.8 ± 0.4) h vs. (2.7 ± 0.4) h], blood loss [(191.9 ± 81.5) ml vs. (186.0 ± 81.7) ml], the incidence of postoperative complications (18.1% vs. 15.3%), length of hospital stay [(12.3 ± 4.2) d vs. (11.9 ± 3.2) d] and 3-year survival rate (63% vs. 57%) (all P>0.05). In the study group, there were 15 patients (20.8%) with positive No.13 lymph nodes, and the 3-year survival rate was 13%, significantly lower compared to those with negative No.13 lymph node (73%, n=57) (P<0.05). Multivariate analysis showed that N stage (P<0.01) and histological type (P<0.05) were independently associated with No.13 lymph node metastasis. CONCLUSION: No.13 lymph node dissection for TNMII-III stage gastric cancer is feasible and necessary.