Phytochemical Cue for the Fitness Costs of Herbicide-Resistant Weeds.

Despite increasing knowledge of the fitness costs of viability and fecundity involved in the herbicide-resistant weeds, relatively little is known about the linkage between herbicide resistance costs and phytochemical cues in weed species and biotypes. This study demonstrated relative fitness and phytochemical responses in six herbicide-resistant weeds and their susceptible counterparts. There were significant differences in the parameters of viability (growth and photosynthesis), fecundity fitness (flowering and seed biomass) and a ubiquitous phytochemical (-)-loliolide levels between herbicide-resistant weeds and their susceptible counterparts. Fitness costs occurred in herbicide-resistant Digitaria sanguinalis and Leptochloa chinensis but they were not observed in herbicide-resistant Alopecurus japonicas, Eleusine indica, Ammannia arenaria, and Echinochloa crus-galli. Correlation analysis indicated that the morphological characteristics of resistant and susceptible weeds were negatively correlated with (-)-loliolide concentration, but positively correlated with lipid peroxidation malondialdehyde and total phenol contents. Principal component analysis showed that the lower the (-)-loliolide concentration, the stronger the adaptability in E. crus-galli and E. indica. Therefore, not all herbicide-resistant weeds have fitness costs, but the findings showed several examples of resistance leading to improved fitness even in the absence of herbicides. In particular, (-)-loliolide may act as a phytochemical cue to explain the fitness cost of herbicide-resistant weeds by regulating vitality and fecundity.

Kin Recognition in an Herbicide-Resistant Barnyardgrass (Echinochloa crus-galli L.) Biotype.

Despite increasing evidence of kin recognition in natural and crop plants, there is a lack of knowledge of kin recognition in herbicide-resistant weeds that are escalating in cropping systems. Here, we identified a penoxsulam-resistant barnyardgrass biotype with the ability for kin recognition from two biotypes of penoxsulam-susceptible barnyardgrass and normal barnyardgrass at different levels of relatedness. When grown with closely related penoxsulam-susceptible barnyardgrass, penoxsulam-resistant barnyardgrass reduced root growth and distribution, lowering belowground competition, and advanced flowering and increased seed production, enhancing reproductive effectiveness. However, such kin recognition responses were not occurred in the presence of distantly related normal barnyardgrass. Root segregation, soil activated carbon amendment, and root exudates incubation indicated chemically-mediated kin recognition among barnyardgrass biotypes. Interestingly, penoxsulam-resistant barnyardgrass significantly reduced a putative signaling (-)-loliolide production in the presence of closely related biotype but increased production when growing with distantly related biotype and more distantly related interspecific allelopathic rice cultivar. Importantly, genetically identical penoxsulam-resistant and -susceptible barnyardgrass biotypes synergistically interact to influence the action of allelopathic rice cultivar. Therefore, kin recognition in plants could also occur at the herbicide-resistant barnyardgrass biotype level, and intraspecific kin recognition may facilitate cooperation between genetically related biotypes to compete with interspecific rice, offering many potential implications and applications in paddy systems.

Stronger mutualistic interactions with arbuscular mycorrhizal fungi help Asteraceae invaders outcompete the phylogenetically related natives.

Mutualistic interactions with arbuscular mycorrhizal fungi (AMF) greatly affect the outcome of plant-plant competition, especially for invasive plants competing against native plants. We examined the effects of AMF on the competition between invasive Asteraceae plants and the phylogenetically related native plants. We compared the performance of seven invasive Asteraceae plants from different genera with that of their phylogenetically related native counterparts in response to AMF in monocultures and mixed cultures. We investigated how interactions with AMF impact the competition between Asteraceae relatives. Total biomass increased with AMF colonization in both invasive and native plants. Arbuscular mycorrhizal fungi improved the competitiveness of invasive plants, but decreased that of native plants. Competition increased the shoot nitrogen, phosphorus and root myristic acid concentrations and relative expression of fatty acid transporter genes (RiFAT1 and RiFAT2) in AMF-colonized invasive plants, but decreased those in AMF-colonized native plants. Structural equation models indicated that the presence of AMF increased the uptake of phosphorus, but not nitrogen, by invasive plants, which probably provided more myristic acids to symbiotic AMF in return. These results suggest that invasive Asteraceae plants have greater mutualistic interactions with AMF than their phylogenetically related native counterparts, potentially contributing to invasion success.

Mechanism of protective role of miR-874-3p in intervertebral disc degeneration.

Background: The intervertebral disc can increase the amplitude of spinal motion, withstand pressure, buffer vibration, and protect the brain and spinal cord. It is also the main reason why height changes, but the regulatory mechanism is still unclear, and this study mainly explored the role of miR-874-3p in intervertebral disc degeneration (IDD). Methods: The mechanism and perform correlation analysis of miR-874-3p and the pathological degree and prognosis of patients with IDD. miR-874-3p is involved in the progression of several diseases, such as cell differentiation, proliferation, apoptosis and extracellular matrix degradation, overexpressing cell line GV369-miR-874-3p-NP was obtained by infected nucleus pulposus (NP) cells, and the empty vector GV369-NP group was set with the blank group. The expression of the tag protein (green fluorescent protein, GFP) was visualized by fluorescence microscopy, followed by real-time polymerase chain reaction (PCR) method to detect miR-874-3p expression, apoptosis by flow cytometry, luciferase reporter analysis for verifying the targeting relationship between miR-874-3p, caspase-3, B-cell lymphoma-2 (Bcl-2) and Bax in cells, and examined the changes in cellular mitochondrial membrane potential using kits. Results: The expression of miR-874-3p was significantly reduced in IDD patients, and was negatively correlated with matrix metallopeptidase 2 (MMP2) and downregulated matrix metallopeptidase 3 (MMP3) in the NP cells. In addition, western blot revealed that overexpression of miR-874-3p increased the aggregation protein level in the NP cells. Conclusions: miR-874-3p can inhibit the cell death of IDD, and not only participate in caspase-3 and Fas-associating protein with a novel death domain (FADD)-mediated apoptosis through targeted regulation of exogenous MMP2/MMP3 pathway, but also play a role in cell apoptosis through mitochondrial pathway.

Fiber-optic large-depth 3D chromatic confocal endomicroscopy.

Current endoscopy techniques have difficulties to provide both high resolution and large imaging depth, which significantly hinders the early diagnosis of gastric cancer. Here, we developed a label-free, large-depth, three-dimensional (3D) chromatic reflectance confocal endomicroscopy. In order to solve the problem of insufficient imaging depth of traditional chromatic confocal microscopy, a customized miniature objective lens both with large chromatic focal shift and correction for spherical aberration was used to focus light of different wavelengths at different depths of the sample simultaneously, and a fiber bundle containing 50000 single-mode cores was used to collect the confocal reflectance signal. To acquire detailed information along the axial direction at a faster speed, a high-speed multi-pixel spectrometer was used to realize simultaneous detection of multi-depth signals. Specifically, we have built up a label-free fiber-optic 3D chromatic reflectance confocal endomicroscopy, with 2.3 µm lateral resolution, imaging depth of 570 µm in 3D phantom and 220 µm in tissue, and 1.5 Hz 3D volumetric frame rate. We have demonstrated that the fiber-optic 3D chromatic confocal endomicroscopy can be used to image human gastric tissues ex vivo, and provide important morphological information for diagnosis without labeling. These results show the great potential of the fiber-optic 3D chromatic confocal endomicroscopy for gastric cancer diagnosis.

Latent Cytomegalovirus Reactivation in Patients With Liver Failure: A 10-Year Retrospective Case-Control Study, 2011-2020.

Background: The aim of this study was to explore potential risk factors for cytomegalovirus (CMV) reactivation and their impact on liver failure patient outcomes. Methods: A 10-year retrospective case-control study was conducted in adult participants, who were diagnosed with liver failure and had undergone CMV DNA tests. CMV reactivation cases were matched with controls at a 2:1 ratio based on age, sex, and year of admission. Univariate and multivariate analyses were used to explore risk factors for CMV reactivation. Results: Between January 2011 and April 2020, 198 adult patients with liver failure and available CMV DNA test results were enrolled into the study. Among them, 33 patients had detectable CMV DNA in their plasma (16.7%). Clinical manifestations and liver function were comparable between the CMV reactivation and non-reactivation groups. However, CMV reactivation may triple mortality in patients with liver failure. We found that nearly 50% of patients in the CMV-positive group received glucocorticoids, compared to 13.6% in the CMV-negative group (P=0.000). The median total glucocorticoid dose included 836.5 mg of methylprednisolone (IQR 308.7-1259.0 mg) in the CMV-positive group, which was significantly higher than that in the CMV-negative group. A multivariate analysis revealed that glucocorticoid use significantly increased the risk of CMV reactivation (adjusted OR, 4.84; 95% CI, 1.61-14.49; P=0.005). Patients with CMV reactivation tended to be associated with higher white cell counts (adjusted OR, 1.21; 95% CI, 1.08-1.36; P=0.002). Conclusions: High intravenous glucocorticoid doses may be the most important risk factor for CMV reactivation in liver failure.

Clinical study on the effect of intramedullary fixation and extramedullary fixation on unstable intertrochanteric fractures.

BACKGROUND: Intertrochanteric fracture of femur is a common fracture in the elderly, and the number of intramedullary nails used to manage intertrochanteric fractures has steadily increased, but the evidence for the clinical efficacy of this practice is lacking. The present study retrospectively compared the clinical outcomes and imaging features of patients with unstable intertrochanteric hip fractures treated with traditional extramedullary hip screws (AO/OTA 31-A2) and patients with the same injury treated with newer intramedullary screws. METHODS: Lower limb measurement (LLM) for the main results of the hip-specific tools, functional independence measure (FIM), and "timed up and go" (TUG) to test the scale and timing of the 2-minute walk test were used as secondary tools for clinical outcomes. Other detailed radiological parameters to evaluate the fracture movement, such as heterotopic ossification, and implant failure, were also recorded. RESULTS: There were no significant differences between the intramedullary and extramedullary treatment groups in terms of the measures acquired by the primary or secondary clinical outcome tools (P>0.05), but the radiographic parameters favored the intramedullary treatment group as it showed reduced femoral neck shortening. CONCLUSIONS: Although treatment with intramedullary nailing resulted in better radiographic assessment results, this did not translate into better functional recovery outcomes.

[Safety evaluation of allelochemical derivative pyrone on different millet varieties]. / åŒ–æ„Ÿç‰©è´¨è¡ç”Ÿç‰©å¡å–ƒé ®å¯¹ä¸åŒè°·å­å“ç§çš„å®‰å ¨æ€§è¯„ä»·.

The development of new herbicides based on allelochemicals is a potential strategy of weed control in arable field. Pyrone, a novel derivative of tricin, has significant inhibitory effects on weeds. Its safety for crops, especially for millet that are sensitive to commercial herbicides, is still poorly understood. In this study, germination test and pot experiments were conducted to evaluate the safety of pyrone on 20 millet varieties, compared with 2,4-D. The results showed that, except that Jinfen109 was sensitive to high concentration 2,4-D, both pyrone and 2,4-D had no effect on the germination rates of other varieties. Results of the pot experiment showed that pyrone treatment significantly increased the chlorophyll content of millet by 9.0%-67.9%, which was the greatest for Jigu 42. Pyrone treatment did not affect maximal photochemical efficiency, potential photochemical activity, actual photochemical efficiency, and non-photochemical quenching coefficient. On the contrary, 2,4-D significantly inhibited the fluorescence parameters of millet varieties. Pyrone treatment increased the activities of superoxide dismutase, peroxidase and catalase in leaves of Dunza16, Jigu 39, Jigu 41 and Jingu 28, with the magnitude of enhancement being higher than 2,4-D. The results indicated that the allelochemical derivative pyrone is highly safe to the growth of millet seedlings and has the potential to be a new herbicide to millet field.

[Allelopathic effects of water extracts from different parts of foxtail millet straw on three kinds of weeds]. / 谷子秸秆不同部位水浸液对3种杂草的化感作用.

We examined the allelopathic effect of extracts from different parts of foxtail millet straw with different concentrations (undiluted water extracts, 10-fold, 50-fold, and 100-fold dilution) on three different kinds of malignant weeds (Amaranthus retroflexus, Chenopodium album, and Setaria viridis) by water extract. In this experiment, we measured biological indicators for seed germination period and potted seedling physiological parameters. The results showed that water extract of foxtail millet leaves and stems had significant allelopathic effects on the three species of weeds, with the effects of different concentrations being different. Undiluted water extract inhibited the growth, while dilution (10-fold, 50-fold, 100-fold dilution) promoted the growth. Under the treatment of undiluted water extract of leaf and stem, the germination rate of three weeds decreased 63.9%, 37.3% and 41.7%, respectively, while root length was only 27.8%, 37.8% and 18.4% of the control. The bud length was only 34.5%, 27.7% and 17.6% of the control. The net photosynthetic rate accounted for 66.6%, 89.9% and 88.2% of the control. The transpiration rate accounted for 69.0%, 87.5% and 56.1% of the control, while the synthesis allelopathic index of the three weeds were -0.699, -0.716 and -0.795 by undiluted water extract, respectively. Results implied strong allelopathic inhibition. The allelopathy promoting effect of dilution increased first and then decreased with the increases of dilution folds. Among which, 50-fold dilution had the strongest promoting effect with the germination rate, root length and bud length of the three weeds being significantly different from those of the control, with the synthesis allelopathic index being 0.261, 0.217, and 0.165, respectively. A large number of associated weeds grow in foxtail millet field which is related to the leaching of allelopathic substances in straw.

Circadian clock associates with tumor microenvironment in thoracic cancers.

The application of cancer chronotherapy is to treat cancers based on at specific times during circadian rhythms. Previous studies have characterized the impact of circadian clock on tumorigenesis and specific immune cells. Here, by using multi-omics computation techniques, we systematically characterized the distinct roles of core circadian clock genes in thoracic cancers including lung adenocarcinoma, lung squamous cell carcinoma, and esophageal carcinoma. Strikingly, a wide range of core clock genes are epigenetically altered in lung adenocarcinomas and lung squamous cell carcinomas but not esophageal carcinomas. Further cancer hallmark analysis reveals that several core clock genes highly correlate with apoptosis and cell cycle such as RORA and PER2. Interestingly, our results reveal that CD4 and CD8 T cells are correlated with core clock molecules especially in lung adenocarcinomas and lung squamous cell carcinomas, indicating that chrono-immunotherapy may serve as a candidate option for future cancer management.

Design and Synthesis of Novel 4-Hydroxyl-3-(2-phenoxyacetyl)-pyran-2-one Derivatives for Use as Herbicides and Evaluation of Their Mode of Action.

In order to develop a novel herbicide containing the ß-triketone motif, a series of 4-hydroxyl-3-(2-phenoxyacetyl)-pyran-2-one derivatives were designed and synthesized. The bioassay results showed that compound II15 had good pre-emergent herbicidal activity even at a dosage of 187.5 g ha-1. Moreover, compound II15 showed a broader spectrum of weed control when compared with a commercial herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), and displayed good crop safety to Triticum aestivum L. and Zea mays Linn. when applied at 375 g ha-1 under pre-emergence conditions, which indicated its great potential as a herbicide. More importantly, studying the molecular mode of action of compound II15 revealed that the novel triketone structure is a proherbicide of its corresponding phenoxyacetic acid auxin herbicide, which has a herbicidal mechanism similar to that of 2,4-D. The present work indicates that the 4-hydroxyl-3-(2-phenoxyacetyl)-pyran-2-one motif may be a potential lead structure for further development of novel auxin-type herbicides.

Baicalin relieves inflammation stimulated by lipopolysaccharide via upregulating TUG1 in liver cells.

Hepatitis has become a major social, health, and economic problem worldwide. Herein, we tested the beneficial influence of baicalin, a flavonoid extracted from the roots of Scutellaria baicalensis, on human normal liver L-02 and THLE2 cell apoptosis and inflammatory reaction stimulated by lipopolysaccharide (LPS) and possible molecular mechanisms. L-02 and THLE2 cell viability and apoptosis after LPS and/or baicalin treatment were tested using CCK-8 assay and Annexin V-FITC/PI apoptosis kit, respectively. qRT-PCR was used to measure the MCP-1, IL-6, TNF-α, and lncRNA taurine upregulated gene 1 (TUG1) expressions in L-02 and THLE2 cells. sh-TUG1 was transfected to knockdown TUG1. SB203580 was used as inhibitor of p38MAPK pathway, while SP600125 was used as inhibitor of JNK pathway. We discovered that LPS stimulation caused L-02 and THLE2 cell apoptosis and inflammatory reaction. Baicalin relieved the L-02 and THLE2 cell apoptosis and inflammatory reaction stimulated by LPS. Moreover, LPS lowered the TUG1 expression in L-02 cells, while baicalin promoted the TUG1 expression in L-02 and L-02 and THLE2 cells, as well as inactivated p38MAPK and JNK pathways in LPS-stimulated L-02 cells. Besides, knockdown of TUG1 activated p38MAPK and JNK pathways and promoted inflammatory cytokine expression in L-02 cells. In conclusion, this study further affirmed the beneficial influences of baicalin on LPS-stimulated human normal liver cell apoptosis and inflammatory reaction. Baicalin relived liver cell inflammation stimulated by LPS might be via upregulating TUG1 and then inactivating p38MAPK and JNK pathways.

The impact of immunosenescence on the efficacy of immune checkpoint inhibitors in melanoma patients: a meta-analysis.

BACKGROUND: Immunosenescence, the age-related decline of immunity, affects the immune responses of melanoma patients. Through immune responses, immune checkpoint inhibitors (ICIs) exert their antitumor robustness. In different ages of melanoma patients, especially the older patients, the effectiveness of ICIs remains unclear. It is still controversial whether ICIs should be used in treating older patients. MATERIALS AND METHODS: The authors included clinical trials of ICIs in older and younger patients. The authors used hazard ratio (HR) and 95% CI of overall survival (OS). RESULTS: From four phase III randomized clinical trials 2,251 melanoma patients were included. We found that ICIs significantly prolonged the OS for melanoma patients in both younger (HR, 0.71; 95% CI, 0.60-0.82; P<0.001) and older groups (HR, 0.62; 95% CI, 0.41-0.83; P<0.001) compared with controls. Anti-programmed death-1 (PD-1) agents appeared to be more efficient in older melanoma patients (HR, 0.34; 95% CI, 0.14-0.53) versus younger patients (HR, 0.52; 95% CI, 0.26-0.78). CONCLUSION: ICIs significantly prolonged the OS for melanoma patients in both younger and older groups than controls. Anti-PD-1 agents were more efficient in older melanoma patients versus younger patients. ICIs could be used for older melanoma patients.

Plant neighbor detection and allelochemical response are driven by root-secreted signaling chemicals.

Plant neighbor detection and response strategies are important mediators of interactions among species. Despite increasing knowledge of neighbor detection and response involving plant volatiles, less is known about how soil-borne signaling chemicals may act belowground in plant-plant interactions. Here, we experimentally demonstrate neighbor detection and allelopathic responses between wheat and 100 other plant species via belowground signaling. Wheat can detect both conspecific and heterospecific neighbors and responds by increasing allelochemical production. Furthermore, we show that (-)-loliolide and jasmonic acid are present in root exudates from a diverse range of species and are able to trigger allelochemical production in wheat. These findings suggest that root-secreted (-)-loliolide and jasmonic acid are involved in plant neighbor detection and allelochemical response and may be widespread mediators of belowground plant-plant interactions.

Graphitic carbon nitride quantum dots as an "off-on" fluorescent switch for determination of mercury(II) and sulfide.

A rapid method has been developed for the determination of Hg(II) and sulfide by using graphitic carbon nitride quantum dots (g-CNQDs) as a fluorescent probe. The interaction between Hg(II) and g-CNQDs leads to the quenching of the blue g-CNQD fluorescence (with excitation/emission peaks at 390/450 nm). However, the fluorescence can be recovered after addition of sulfide such that the "turn-off" state is switched back to the "turn-on" state. The g-CNQDs were fully characterized by transmission electron microscopy, X-ray diffractometry, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, UV-vis absorption and fluorescence spectroscopy. Under the optimal experimental conditions, this probe is highly selective and sensitive to Hg(II). The linear response to Hg(II) extends from 0.20 to 21 µM with a detection limit of 3.3 nM. In addition, sulfide can be detected via the recovery of fluorescence. The linear response range for sulfide species is from 8.0 to 45 µM with a detection limit of 22 nM. The mechanism of the "turn-off-on" scheme is discussed. The methods have been applied to the analysis of spiked tap water, lake water and wastewater samples. Graphical abstract Schematic of an off-on fluorescent probe for mercury(II). The fluorescence of graphitic carbon nitride quantum dots (g-CNQDs) is quenched by Hg2+ but is recovered after reacting with S2- as it can combine with Hg2+ on the surface of g-CNQDs.

Kin recognition in rice (Oryza sativa) lines.

Kin recognition is an important mediator of interactions within individuals of a species. Despite increasing evidence of kin recognition in natural plant populations, relatively little is known about kin recognition in crop species where numerous cultivars have been generated by artificial selection. We identified rice (Oryza sativa) cultivars with the ability for kin recognition from two sets of indica-inbred and indica-hybrid lines at different levels of genetic relatedness. We then assessed this ability among kin and nonkin and tested potential mechanisms in a series of controlled experiments and field trails. Rice cultivars with the ability for kin recognition were capable of detecting the presence of kin and nonkin and responded to them by altering root behavior and biomass allocation, particularly for grain yield. Furthermore, we assessed the role of root exudates and found a root-secreted nitrogen-rich allantoin component to be responsible for kin recognition in rice lines. Kin recognition in rice lines mediated by root exudates occurs in a cultivar-dependent manner. Rice cultivars with the ability for kin recognition may increase grain yield in the presence of kin. Such an improvement of grain yield by kin recognition of cultivar mixtures offers many implications and applications in rice production.