Flexible Data Rate Allocation Using Non-Orthogonal Multiple Access (NOMA) in a Mode Division Multiplexing (MDM) Optical Power Splitter for System-on-Chip Networks.

We put forward and demonstrate a silicon photonics (SiPh)-based mode division multiplexed (MDM) optical power splitter that supports transverse-electric (TE) single-mode, dual-mode, and triple-mode (i.e., TE0, TE1, and TE2). An optical power splitter is needed for optical signal distribution and routing in optical interconnects. However, a traditional optical splitter only divides the power of the input optical signal. This means the same data information is received at all the output ports of the optical splitter. The powers at different output ports may change depending on the splitting ratio of the optical splitter. The main contributions of our proposed optical splitter are: (i) Different data information is received at different output ports of the optical splitter via the utilization of NOMA. By adjusting the power ratios of different channels in the digital domain (i.e., via software control) at the Tx, different channel data information can be received at different output ports of the splitter. It can increase the flexibility of optical signal distribution and routing. (ii) Besides, the proposed optical splitter can support the fundamental TE0 mode and the higher modes TE1, TE2, etc. Supporting mode-division multiplexing and multi-mode operation are important for future optical interconnects since the number of port counts is limited by the chip size. This can significantly increase the capacity besides wavelength division multiplexing (WDM) and spatial division multiplexing (SDM). The integrated SiPh MDM optical power splitter consists of a mode up-conversion section implemented by asymmetric directional couplers (ADCs) and a Y-branch structure for MDM power distribution. Here, we also propose and discuss the use of the Genetic algorithm (GA) for the MDM optical power splitter parameter optimization. Finally, to provide adjustable data rates at different output ports after the MDM optical power splitter, non-orthogonal multiple access-orthogonal frequency division multiplexing (NOMA-OFDM) is also employed. Experimental results validate that, in three modes (TE0, TE1, and TE2), user-1 and user-2 achieve data rates of (user-1: greater than 22 Gbit/s; user-2: greater than 12 Gbit/s) and (user-1: greater than 12 Gbit/s; user-2: 24 Gbit/s), respectively, at power-ratio (PR) = 2.0 or 3.0. Each channel meets the hard-decision forward-error-correction (HD-FEC, i.e., BER = 3.8 × 10-3) threshold. The proposed method allows flexible data rate allocation for multiple users for optical interconnects and system-on-chip networks.

Corrigendum: No safe renal warm ischemia time-The molecular network characteristics and pathological features of mild to severe ischemia reperfusion kidney injury.

[This corrects the article DOI: 10.3389/fmolb.2022.1006917.].

Targeted VEGFA therapy in regulating early acute kidney injury and late fibrosis.

Damage to peritubular capillaries is a key process that contributes to acute kidney injury (AKI) progression. Vascular endothelial growth factor A (VEGFA) plays a critical role in maintaining the renal microvasculature. However, the physiological role of VEGFA in various AKI durations remains unclear. A severe unilateral ischemia‒reperfusion injury model was established to provide an overview of VEGFA expression and the peritubular microvascular density from acute to chronic injury in mouse kidneys. Therapeutic strategies involving early VEGFA supplementation protecting against acute injury and late anti-VEGFA treatment for fibrosis alleviation were analyzed. A proteomic analysis was conducted to determine the potential mechanism of renal fibrosis alleviation by anti-VEGFA. The results showed that two peaks of extraglomerular VEGFA expression were observed during AKI progression: one occurred at the early phase of AKI, and the other occurred during the transition to chronic kidney disease (CKD). Capillary rarefaction progressed despite the high expression of VEGFA at the CKD stage, and VEGFA was associated with interstitial fibrosis. Early VEGFA supplementation protected against renal injury by preserving microvessel structures and counteracting secondary tubular hypoxic insults, whereas late anti-VEGFA treatment attenuated renal fibrosis progression. The proteomic analysis highlighted an array of biological processes related to fibrosis alleviation by anti-VEGFA, which included regulation of supramolecular fiber organization, cell-matrix adhesion, fibroblast migration, and vasculogenesis. These findings establish the landscape of VEGFA expression and its dual roles during AKI progression, which provides the possibility for the orderly regulation of VEGFA to alleviate early acute injury and late fibrosis.

[Structure and Distribution Characteristics of Bacterial Community in Boqing River Water].

The structure and distribution of bacterial communities should be influenced by urban and industrial activities. The Boqing River, which flows through towns and a copper tailing reservoir, is an important tributary of Xiaolangdi Reservoir in South Shanxi. In order to clarify the structure and distribution characteristics of the bacterial community in the Boqing River, we collected water samples along the Boqing River. The diversity characteristics of bacterial communities were analyzed, and their relationships with environmental factors were also explored. The results showed that the abundance and diversity of the bacterial community were higher in the downstream than that in the upstream of the river. Both of the parameters first decreased and then increased along the river. The lowest and highest bacterial abundance and diversity existed in the copper tailing reservoir and the site adjacent to the Xiaolangdi Reservoir, respectively. Proteobacteria, Actinobacteriota, Bacteroidota, and Firmicutes were dominant taxa at the bacterial phylum level in the river, and Acinetobacter, Limnohabitans, Pseudoarthrobacter, and Flavobacterium were dominant taxa at the genus level. Acinetobacter had the highest relative abundance in urban water of the river, which was significantly positively correlated with TC. Flavobacterium was significantly correlated with As. Considering its co-occurrence with As, we speculated that As might contribute to the spread of pathogenic bacteria in the study area. The results of this study were of great importance for the assessment of aquatic health under a complex environment.

No safe renal warm ischemia time-The molecular network characteristics and pathological features of mild to severe ischemia reperfusion kidney injury.

Ischemic acute kidney injury (AKI) has always been a hot and difficult research topic in the field of renal diseases. This study aims to illustrate the safe warm ischemia time of kidney and the molecular network characteristics and pathological features of mild to severe ischemia reperfusion kidney injury. We established varying degrees of renal injury due to different ischemia time (0 min, 16 min, 18 min, 20 min, 22 min, 24 min, 26 min, 28 min, and 30 min) on unilateral (left kidney) ischemia-reperfusion injury and contralateral (right kidney) resection (uIRIx) mouse model. Mice were sacrificed 24 h after uIRIx, blood samples were harvested to detect serum creatinine (Scr), and kidney tissue samples were harvested to perform Periodic Acid-Schiff (PAS) staining and RNA-Seq. Differentially expressed genes (DEGs) were identificated, time-dependent gene expression patterns and functional enrichment analysis were further performed. Finally, qPCR was performed to validated RNA-Seq results. Our results indicated that there was no absolute safe renal warm ischemia time, and every minute of ischemia increases kidney damage. Warm ischemia 26min or above in mice makes severe kidney injury, renal pathology and SCr were both significantly changed. Warm ischemia between 18 and 26 min makes mild kidney injury, with changes in pathology and renal molecular expression, while SCr did not change. No obvious pathological changes but significant differences in molecular expression were found less than 16min warm ischemia. There are two key time intervals in the process of renal ischemia injury, 0 min-16 min (short-term) and 26 min-28 min (long-term). Gene expression of immune-related pathways were most significantly down-regulated in short-term ischemia, while metabolism-related pathways were the mainly enriched pathway in long-term ischemia. Taken together, this study provides novel insights into safe renal artery occlusion time in partial nephrectomy, and is of great value for elucidating molecular network characteristics and pathological features of mild to severe ischemia reperfusion kidney injury, and key genes related to metabolism and immune found in this study also provide potential diagnostic and therapeutic biomarkers for AKI.

Transient upregulation of EGR1 signaling enhances kidney repair by activating SOX9+ renal tubular cells.

Background: Acute kidney injury (AKI) is associated with damage to the nephrons and tubular epithelial cells (TECs), which can lead to chronic kidney disease and end-stage renal disease. Identifying new biomarkers before kidney dysfunction will offer crucial insight into preventive and therapeutic options for the treatment of AKI. Early growth response 1 (EGR1) has been found to be a pioneer transcription factor that can sequentially turn on/off key downstream genes to regulate whole-body regeneration processes in the leopard worm. Whether EGR1 modulates renal regeneration processes in AKI remains to be elucidated. Methods: AKI models of ischemia-reperfusion injury (IRI) and folic acid (FA) were developed to investigate the roles of EGR1 in kidney injury and regeneration. To further determine the function of EGR1, Egr1-/- mice were applied. Furthermore, RNA sequencing of renal TECs, Chromatin Immunoprecipitation (ChIP) assay, and Dual-luciferase reporter assay were carried out to investigate whether EGR1 affects the expression of SOX9. Results: EGR1 is highly expressed in the kidney after AKI both in humans and mice through analysis of the Gene Expression Omnibus (GEO) database. Furthermore, we verified that EGR1 rapidly up-regulates in the very early stage of IRI and nephrotoxic models of AKI, and validation studies confirmed the essential roles of EGR1 in renal tubular cell regeneration. Further experiments affirmed that genetic inhibition of Egr1 aggravates the severity of AKI in mouse models. Furthermore, our results revealed that EGR1 could increase SOX9 expression in renal TECs by directly binding to the promoter of the Sox9 gene, thus promoting SOX9+ cell proliferation by activating the Wnt/ß-catenin pathway. Conclusions: Together, our results demonstrated that rapid and transient induction of EGR1 plays a renoprotective role in AKI, which highlights the prospects of using EGR1 as a potential therapeutic target for the treatment of AKI.

A novel phosphodiesterase 9A inhibitor LW33 protects against ischemic stroke through the cGMP/PKG/CREB pathway.

BACKGROUND: Ischemic stroke is one of the leading causes of mortality worldwide. The available treatments are not effective. Phosphodiesterase 9A (PDE9A) is an intracellular cyclic guanosine monophosphate (cGMP) hydrolase considered to be a promising therapeutic target for brain diseases. This study explored neuroprotective effects and the underlying mechanism of LW33, a novel PDE9A inhibitor, on ischemic stroke in vitro and in vivo. METHODS: A middle cerebral artery occlusion (MCAO) model was established in adult male Sprague-Dawley rats and an oxygen-glucose deprivation/reoxygenation (OGD/R) model was established in human SH-SY5Y cells to mimic ischemia-reperfusion injury in vitro. RESULTS: LW33 increased cell viability, reduced lactate dehydrogenase activity, and OGD/R-induced apoptosis of SH-SY5Y cells. The protective effects of LW33 against stroke occurred in the recovery phase. LW33 administration significantly reduced cerebral infarction volume in MCAO rats, without causing significant deformation or necrosis of neurons in the cortex. LW33 also improved learning and cognitive dysfunction and reduced other pathological changes in MCAO rats in the recovery period. Moreover, LW33 stimulated the cGMP/PKG/CREB pathway and up-regulated the expression of the apoptosis-related proteins, and this effect was reversed by KT5823 treatment. CONCLUSION: LW33 inhibited cell apoptosis and promoted neuronal repair to alleviate OGD/R and MCAO induced pathological alterations via the cGMP/PKG/CREB pathway, indicating that LW33 may be a promising therapeutic target for ischemic stroke.

Effects of Chinese medicine herbal residues on antibiotic resistance genes and the bacterial community in chicken manure composting.

The use of livestock manure is an important way for antibiotic resistance genes (ARGs) to enter the environment, and composting is an effective method for removing ARGs from livestock manure. In this study, different volume ratios of Chinese medicinal herbal residues (CMHRs) were added to laboratory-scale chicken manure composting to evaluate their effects, if any, on the behavior of ARGs, mobile genetic elements (MGEs), and the bacterial community. At the end of the composting period, the composition of the microbial community changed. Firmicutes decreased and Bacteroidetes increased. The most striking effect was that the relative abundance of the 21 ARGs and 5 MGEs detected decreased by varying degrees in the different treatments (except for sulI and intI1). The removal rate of the ARGs increased with the increased addition of CMHRs. The correlations between transferase genes (tnpA and tnpA-02) and ARGs were significant (p < 0.05); therefore, transposons play an important role in the horizontal gene transfer of ARGs in chicken manure. The results imply that CMHRs would be an effective bulking agent for the removal of ARGs from chicken manure composting.

Integrating object detection and image segmentation for detecting the tool wear area on stitched image.

Flank wear is the most common wear that happens in the end milling process. However, the process of detecting the flank wear is cumbersome. To achieve comprehensively automatic detecting the flank wear area of the spiral end milling cutter, this study proposed a novel flank wear detection method of combining the template matching and deep learning techniques to expand the curved surface images into panorama images, which is more available to detect the flank wear areas without choosing a specific position of cutting tool image. You Only Look Once v4 model was employed to automatically detect the range of cutting tips. Then, popular segmentation models, namely, U-Net, Segnet and Autoencoder were used to extract the areas of the tool flank wear. To evaluate the segmenting performance among these models, U-Net model obtained the best maximum dice coefficient score with 0.93. Moreover, the predicting wear areas of the U-Net model is presented in the trend figure, which can determine the times of the tool change depend on the curve of the tool wear. Overall, the experiments have shown that the proposed methods can effectively extract the tool wear regions of the spiral cutting tool. With the developed system, users can obtain detailed information about the cutting tool before being worn severely to change the cutting tools in advance.

An Automatic Bleeding-Rank System for Transurethral Resection of the Prostate Surgery Videos Using Machine Learning.

Benign prostatic hyperplasia (BPH) is the main cause of lower urinary tract symptoms (LUTS) in aging males. Transurethral resection of the prostate (TURP) surgery is performed by a cystoscope passing through the urethra and scraping off the prostrate piece by piece through a cutting loop. Although TURP is a minimally invasive procedure, bleeding is still the most common complication. Therefore, the evaluation, monitoring, and prevention of interop bleeding during TURP are very important issues. The main idea of this study is to rank bleeding levels during TURP surgery from videos. Generally, to judge bleeding level by human eyes from surgery videos is a difficult task, which requires sufficient experienced urologists. In this study, machine learning-based ranking algorithms are proposed to efficiently evaluate the ranking of blood levels. Based on the visual clarity of the surgical field, the four ranking of blood levels, including score 0: excellent; score 1: acceptable; score 2: slightly bad; and 3: bad, were identified by urologists who have sufficient experience in TURP surgery. The results of extensive experiments show that the revised accuracy can achieve 90, 89, 90, and 91%, respectively. Particularly, the results reveal that the proposed methods were capable of classifying the ranking of bleeding level accurately and efficiently reducing the burden of urologists.

[Soil Fungal Community Structure and Functional Diversity in a Copper Tailing Dam and Its Surrounding Areas].

Soil fungal communities are reconstructed under heavy metal stress. This study was conducted to explore the structural and functional diversity of soil fungal communities under different land-use patterns, namely grassland and farmland, in 15-year-old or 10-year-old poplar plantations (Populus deltoides cv. 'zhonghuahongye') near the Shibahe copper tailing dam and the surrounding area, located in Yuanqu County, Shanxi. The results indicated that the abundance and diversity of fungal communities were the highest in the 15-year-old poplar plantation and lowest in the grassland on the tailing dam. The dominant fungal groups in the study area were Ascomycota, Basidiomycota, and Mortierellomycota. The Ascomycota members were the most abundant at all four sampling sites, reaching 92.92% of the fungal community in the grassland on the tailing dam. The highest functional diversity of carbon utilization was found in the soil fungal communities of the 15-year-old poplar plantations; moreover, the diversity in the grassland on the tailing dam was significantly higher than that in the farmland and in the 10-year-old poplar plantation. Meanwhile, we also observed the highest glucoside carbon source utilization efficiency in the grassland. Notably, the correlation analysis revealed that Ascomycota was significantly correlated with the utilization efficiency of the glucoside carbon source in our study area. Moreover, the soil total nitrogen content, but not the soil heavy metal content, was significantly correlated with the abundance of the soil fungal community. There were significant correlations between the cadmium and arsenic contents and the soil fungal community diversity indices. Our results indicated that the soil fungal communities were more influenced by soil fertility and land use than by the soil heavy metal content. This study underlies the application of soil fungal communities in soil remediation of heavy metal-contaminated areas.

Attractiveness-related recognition bias captures the memory of the beholder.

Earlier electroencephalographic studies have compared attractive and unattractive faces and between faces with other objects, such as flowers, without revealing if a recognition memory bias toward faces and flowers exists or whether humans exhibit enhanced specific components toward all attractive objects or only toward attractive faces. For objects with similar degrees of attractiveness, we sought to determine if the N170, P1, and N250 reflect upon the attractiveness of faces and flowers and demonstrated by comparing event-related potentials of humans' different perceptual mechanisms recognizing high attractive faces and high attractive flowers. The repeated high attractive faces tended to elicit a larger N170. Simultaneously, the P1 was preferentially associated with the repeated high attractive flowers, but both indicated that the repetitive enhancement effect only occurred on repeated attractive faces. Thus, differences existed in the perceptual mechanisms for processing repeated high attractive faces and repeated high attractive flowers. However, there was no significant difference in N250 between repeated faces and repeated flowers or between high attractive faces and high attractive flowers. Consequently, high attractive faces and high attractive flowers capture the beholder's memory bias in different processing stages. The N170 and P1 components are affected by attractiveness, thereby demonstrating the differences between human perceptual mechanisms in recognizing high attractive faces and objects.

Elevated soluble programmed death-ligand 1 levels indicate immunosuppression and poor prognosis in hepatocellular carcinoma patients undergoing transcatheter arterial chemoembolization.

AIMS: The present study aimed to determine the prognostic significance of soluble Programmed Death-ligand 1 (sPD-L1) in hepatocellular carcinoma (HCC) patients undergoing transcatheter arterial chemoembolization (TACE). METHODS: We treated 114 HCC patients with TACE from 2012 to 2013 and determined their sPD-L1 levels by enzyme-linked immunosorbent assay. We evaluated prognosis according to mRESIST criteria and analyzed prognostic values by Cox regression and Kaplan-Meier analysis. We further evaluated correlations between sPD-L1 level and inflammatory status, as well as immunosuppressive environment. RESULTS: sPD-L1 levels were significantly increased in patients who developed HCC progression (P = 0.002) and death (P < 0.001). Patients with higher pre-treatment sPD-L1 levels had a significantly shorter time to progression (10.50 vs. 18.25 months, P = 0.001) and decreased overall survival (16.50 vs. 28.50 months, P = 0.003). Importantly, sPD-L1 levels positively correlated with SII (r = 0.284, P = 0.002), sIL-2R (r = 0.239, P = 0.010), IL-10 (r = 0.283, P = 0.002), HBV-DNA loads (r = 0.229, P = 0.014), and CRP (r = 0.237, P = 0.011). Moreover, high sPD-L1 levels had increased numbers of Treg cells (FOXP3+; P = 0.026), Macrophage cells (CD68+; P = 0.014), and M2-Macrophage cells (CD163+; P = 0.026) CONCLUSIONS: sPD-L1 level is a prognostic indicator of poor outcomes after TACE. High sPD-L1 might reflect increased immune activation in an immunosuppressive environment that hindered anti-tumor response activity.

Physiological and molecular mechanisms governing the effect of virus-free chewing cane seedlings on yield and quality.

The effects of increasing yield and quality of virus-free chewing cane seedlings and their physiological and molecular basis were studied in this study. Results showed that compared with infected seedlings (the control), the yield of chewing cane stems grown from virus-free seedlings increased by 21.81-29.93%, stem length increased by 28.66-34.49 cm, internode length increased by 2.16-2.68 cm, the single stem weight increased by 20.10-27.68%, the reducing sugar increased by 0.91-1.15% (absolute value), and sucrose increased by - 0.06-1.33% (absolute value). The decrease in sucrose content did not reach significant level, but all other parameters were reached significant level. The chlorophyll content, photosynthetic parameters such as stomatal conductance (Gs), net photosynthetic rate (Pn) and transpiration rate (Tr), the activity of photosynthetic key enzymes ribulose-1,5-bisphosphate carboxylase (Rubisco) and phosphoenolpyruvate carboxylase (PEPC), and gene (pepc, rbcS, and rbcL) expression levels were all greater in virus-free seedlings than infected seedlings. The content of superoxide anion (O2-) and malondialdehyde (MDA) in virus-free seedlings was lower than infected seedlings at the main growth stage. With increased development, the activities of the antioxidant enzymes superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were gradually higher in virus-free seedlings than infected seedlings. Our results indicate that virus-free seedlings may improve photosynthesis efficiency and promote photosynthesis by increasing chlorophyll content, photosynthetic key enzyme activity, and the gene expression levels in leaves. By increasing the activity of antioxidant enzymes, reducing the degree of membrane lipid peroxidation, and improving the stress resistance of chewing cane, the virus-free chewing cane seedlings increased yield and quality. Our findings provide a scientific and theoretical basis for the promotion and application of virus-free chewing cane seedlings.

Deficit of long-term memory traces for words in children with cochlear implants.

OBJECTIVE: Language experience can develop long-term memory traces for speech units in the brain, to ensure efficient processing of speech sounds. However, prelingually deafened children lack sufficient auditory input before cochlear implantation. Whether the experience-dependent long-term memory traces exist in prelingually deafened children with cochlear implants (CIs) remains unclear. METHODS: We presented CI and normal hearing (NH) children with Mandarin Chinese spoken disyllables in an oddball paradigm and recorded event-related potentials. Each disyllable was defined as a meaningful word or a meaningless pseudoword by the tonal information in the second syllable. RESULTS: The amplitude of mismatch negativity (MMN) elicited by words was larger than that elicited by pseudowords in NH children. However, this enhancement of the MMN amplitude was not found in CI children. Behavioral results showed later recognition points for words and lower accuracies for speech comprehension in CI children than in NH children. Furthermore, increased theta power for words compared with pseudowords was only found in NH children. CONCLUSIONS: Our findings indicate a deficit of long-term memory traces for words in prelingually deafened children with cochlear implants. SIGNIFICANCE: Early speech input may be crucial to the formation of long-term memory traces for speech units.

ZTW-41, a Potent Indolizinoquinoline-5,12-Dione Derivative Against Drug-Resistant Staphylococci and Enterococci Bacteria.

ZTW-41, an indolizinoquinoline-5,12-dione derivative, was investigated for antibacterial activity against Gram-positive bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA). In our study, the MIC90s (minimum inhibitory concentrations) of ZTW-41 against MRSA (MRSA, n = 200), methicillin-sensitive S. aureus (MSSA, n = 100), Enterococcus faecalis (E. faecalis, n = 32), and Enterococcus faecium (E. faecium n = 32) were 0.25, 0.25, 0.125, and 8 µg/mL, respectively, whereas the MBC90s (minimum bactericidal concentrations) were 2, 1, 1, and >32 µg/mL, respectively. ZTW-41 maintained its potency at different pH levels (range 5-9) and in starting inoculum size up to 107 CFU/mL. The presence of human serum (25-75%) increased ZTW-41 MICs by two- to eightfold. Time-kill curves showed that ZTW-41 had bactericidal activity against MRSA, MSSA, and E. faecalis strains within 8 hours, and rebound growth occurred after 8 hours except at higher multiples of the MIC (4 × and 8 × ). In the acute toxicity study, no mortality or signs of toxicity was noted in mice after 14 days of observation at doses <50 mg/kg. ZTW-41 exhibited good selectivity indices (SIs) (SI = IC50/MIC90) ranging from 1.12 to 71.76 against clinical isolates, demonstrating excellent therapeutic selectivity in MRSA, MSSA, and E. faecalis strains. Moreover, the in vivo efficacy (effective dose [ED]50 = 6.59 mg/kg) of ZTW-41 was found comparable with vancomycin. Collectively, our favorable results supported ZTW-41 as a promising investigational candidate for treating drug-resistant bacteria infection.

[Effect of Co-composting of Chicken Manure with Chinese Medicinal Herbal Residues on Antibiotic Resistance Genes].

Livestock manure is an important pathway by which antibiotic resistance genes (ARGs) enter the environment. To reduce the occurrence of antibiotic resistance genes in manures, we studied the variations of ARGs and mobile gene elements (MGEs) during the 46-day co-composting of chicken manure with Chinese medicinal herbal residues. The abundance of 100 ARGs and 5 MGEs were measured by Real-Time Quantitative PCR with 0, 3, 7, 14, 28, and 46 d co-composting. We detected 21 ARGs, 2 integrase genes (intI1 and intI2), and 3 transposase genes (tnpA-01, tnpA-02, and tnpA-03). The abundance of 5 MGEs significantly declined with co-composting time, particularly tnpA-01 and tnpA-02, which were reduced by two orders of magnitude. The abundance of aacA/aphD and aadE were significantly reduced (P<0.05) in aminoglycoside resistance genes. In ß-lactam resistance genes, the strongest relationships were demonstrated between blaOXA1 and compost days (P=0.016), and the removal rate was 78.63%. The average removal rate was 90.39% for amide resistance genes, which decreased significantly with composting time. The removal ratios were different among tetracycline resistance genes. For example, the removal ratios of tetG and tetR were 99.77% and 31.72%, respectively. The highest removal rate of qnrD was 99.89%. The removal rate of sulⅢ was as high as 99.88%, while sulⅠ showed an increasing trend. Correlations between ARGs and MGEs were significant correlation for tnpA-01 and ARGs (P<0.05). The trend of ARGs with composting time indicates that the composting of Chinese medicine residues and chicken manure can significantly reduce the abundance of ARGs, thus reducing the risk of ARGs being distributed via livestock manure application.

BrTCP7 Transcription Factor Is Associated with MeJA-Promoted Leaf Senescence by Activating the Expression of BrOPR3 and BrRCCR.

The plant hormone jasmonic acid (JA) has been recognized as an important promoter of leaf senescence in plants. However, upstream transcription factors (TFs) that control JA biosynthesis during JA-promoted leaf senescence remain unknown. In this study, we report the possible involvement of a TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) TF BrTCP7 in methyl jasmonate (MeJA)-promoted leaf senescence in Chinese flowering cabbage. Exogenous MeJA treatment reduced maximum quantum yield (Fv/Fm) and total chlorophyll content, accompanied by the increased expression of senescence marker and chlorophyll catabolic genes, and accelerated leaf senescence. To further understand the transcriptional regulation of MeJA-promoted leaf senescence, a class I member of TCP TFs BrTCP7 was examined. BrTCP7 is a nuclear protein and possesses trans-activation ability through subcellular localization and transcriptional activity assays. A higher level of BrTCP7 transcript was detected in senescing leaves, and its expression was up-regulated by MeJA. The electrophoretic mobility shift assay and transient expression assay showed that BrTCP7 binds to the promoter regions of a JA biosynthetic gene BrOPR3 encoding OPDA reductase3 (OPR3) and a chlorophyll catabolic gene BrRCCR encoding red chlorophyll catabolite reductase (RCCR), activating their transcriptions. Taken together, these findings reveal that BrTCP7 is associated with MeJA-promoted leaf senescence at least partly by activating JA biosynthesis and chlorophyll catabolism, thus expanding our knowledge of the transcriptional mechanism of JA-mediated leaf senescence.

Activation of the Transcription of BrGA20ox3 by a BrTCP21 Transcription Factor Is Associated with Gibberellin-Delayed Leaf Senescence in Chinese Flowering Cabbage during Storage.

Several lines of evidence have implicated the involvement of the phytohormone gibberellin (GA) in modulating leaf senescence in plants. However, upstream transcription factors (TFs) that regulate GA biosynthesis in association with GA-mediated leaf senescence remain elusive. In the current study, we report the possible involvement of a TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) TF BrTCP21 in GA-delayed leaf senescence in Chinese flowering cabbage. Exogenous GA3 treatment maintained a higher value of maximum PSII quantum yield (Fv/Fm) and total chlorophyll content, accompanied by the repression of the expression of senescence-associated genes and chlorophyll catabolic genes, which led to the delay of leaf senescence. A class I member of TCP TFs BrTCP21, was further isolated and characterized. The transcript level of BrTCP21 was low in senescing leaves, and decreased following leaf senescence, while GA3 could keep a higher expression level of BrTCP21. BrTCP21 was further found to be a nuclear protein and exhibit trans-activation ability through transient-expression analysis in tobacco leaves. Intriguingly, the electrophoretic mobility shift assay (EMSA) and transient expression assay illustrated that BrTCP21 bound to the promoter region of a GA biosynthetic gene BrGA20ox3, and activated its transcription. Collectively, these observations reveal that BrTCP21 is associated with GA-delayed leaf senescence, at least partly through the activation of the GA biosynthetic pathway. These findings expand our knowledge on the transcriptional mechanism of GA-mediated leaf senescence.