High temperature (temperature over 35 °C) is an extremely important environmental factor that affects the maize grain quality in Southern China. The effects of heat stress after pollination on grain ...protein and starch deposition and activities of involved enzymes were studied in a pot trail in 2014 and 2015. Results showed that grain dry weight reductions at maturity were 19.8% and 19.1%, whereas starch contents (mg g
) were reduced by 3.0% and 3.3%, and starch accumulation (mg grain
) were reduced 22.2% and 21.8% in 2014 and 2015, respectively. Protein content was decreased by heat stress before 15 DAP and increased thereafter. At maturity, protein contents (mg g
) were increased by 24.5% and 25.3% in 2014 and 2015, while protein accumulation (mg grain
) were not affected by heat stress. In response to heat stress, glutamate synthase activity was enhanced by 29.1-82.9% in 2014 and 2.0-141.8% in 2015, whereas glutamine synthetase activity was reduced by 1.9-43.5% in 2014 and 0.1-27.4% in 2015 throughout the grain filling. The activities of sucrose phosphate synthase were decreased by heat stress at 10-25DAP (12.7-32.0%) in 2014 and 15-20 DAP (23.2-27.5%) in 2015, and activities of sucrose synthase were decreased by heat stress at 5-15 DAP (20.0-45.0%) in 2014 and 15 DAP (22.0%) in 2015, repectively. The activities of enyzmes that involved in starch synthessis were all suppressed by heat stress during grain filling, and the reduction of adenosine diphosphate-glucose pyrophosphorylase, soluble starch synthase, and starch branching enzyme were decreased by 21.3-43.1%, 19.1-29.2%, and 7.0-45.6% in 2014 and 1.8-78.5%, 21.4-51.2%, and 11.0-48.0% in 2015, respectively. Conclusively, grain weight and starch deposition were suppressed by heat stress due to the decreased activities of enzymes involved in starch synthesis, and the increased protein content was due to the enhanced activity of glutamate synthase.
We report a clinical isolate of Burkholderia thailandensis 2022DZh obtained from a patient with an infected wound in southwest China. Genomic analysis indicates that this isolate clusters with B. ...thailandensis BPM, a human isolate from Chongqing, China. We recommend enhancing monitoring and surveillance for B. thailandensis infection in both humans and livestock.
Kernel development and starch formation are the primary determinants of maize yield and quality, which are considerably influenced by drought stress. To clarify the response of maize kernel to ...drought stress, we established well-watered (WW) and water-stressed (WS) conditions at 1-30 days after pollination (dap) on waxy maize (Zea mays L. sinensis Kulesh). Kernel development, starch accumulation, and activities of starch biosynthetic enzymes were significantly reduced by drought stress. The morphology of starch granules changed, whereas the grain filling rate was accelerated. A comparative proteomics approach was applied to analyze the proteome change in kernels under two treatments at 10 dap and 25 dap. Under the WS conditions, 487 and 465 differentially accumulated proteins (DAPs) were identified at 10 dap and 25 dap, respectively. Drought induced the downregulation of proteins involved in the oxidation-reduction process and oxidoreductase, peroxidase, catalase, glutamine synthetase, abscisic acid stress ripening 1, and lipoxygenase, which might be an important reason for the effect of drought stress on kernel development. Notably, several proteins involved in waxy maize endosperm and starch biosynthesis were upregulated at early-kernel stage under WS conditions, which might have accelerated endosperm development and starch synthesis. Additionally, 17 and 11 common DAPs were sustained in the upregulated and downregulated DAP groups, respectively, at 10 dap and 25 dap. Among these 28 proteins, four maize homologs (i.e., A0A1D6H543, B4FTP0, B6SLJ0, and A0A1D6H5J5) were considered as candidate proteins that affected kernel development and drought stress response by comparing with the rice genome. The proteomic changes caused by drought were highly correlated with kernel development and starch accumulation, which were closely related to the final yield and quality of waxy maize. Our results provided a foundation for the enhanced understanding of kernel development and starch formation in response to drought stress in waxy maize.
The effects of protein removal on the physicochemical properties of waxy maize flours were investigated. Protein removal caused significant reduction in the P and S contents of starches. Starch ...granules had a smoother surface and low protein content (<6 g/kg) compared with the flours. Both flours and starches had a typical A‐type X‐ray diffraction pattern, with a crystallinity range of 29.8–32.2% and 27.7–30.6%, respectively. Flours had higher swelling power and solubility, and lower light transmittance than starches. The gelatinization enthalpy and onset temperature of starches were higher compared with those of their counterpart flours. The retrogradation of flours was significantly greater compared with that of starches. Protein removal increased the peak viscosity, trough viscosity, final viscosity, and breakdown, whereas it decreased the setback and pasting temperature. Genotypic differences in those maize were related to the physicochemical characteristics of the flours and starches.
Insufficient light during the growth periods has become one of the main factors restricting maize yield with global climate change. Exogenous hormones application is a feasible measure to alleviate ...abiotic stresses on crop productivity. In this study, a field trial was conducted to investigate the effects of spraying exogenous hormones on yield, dry matter (DM) and nitrogen (N) accumulation, leaf carbon and N metabolism of fresh waxy maize under weak-light stress in 2021 and 2022. Five treatments including natural light (CK), weak-light after pollination (Z), spraying water (ZP1), exogenous Phytase Q9 (ZP2) and 6-benzyladenine (ZP3) under weak-light after pollination were set up using two hybrids suyunuo5 (SYN5) and jingkenuo2000 (JKN2000). Results showed that weak-light stress significantly reduced the average fresh ear yield (49.8%), fresh grain yield (47.9%), DM (53.3%) and N accumulation (59.9%), and increased grain moisture content. The net photosynthetic rate (Pn), transpiration rate (Tr) of ear leaf after pollination decreased under Z. Furthermore, weak-light decreased the activities of RuBPCase and PEPCase, nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase (GOGAT), superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in ear leaves, and increased malondialdehyde (MDA) accumulation. And the decrease was greater on JKN2000. While ZP2 and ZP3 treatments increased the fresh ear yield (17.8%, 25.3%), fresh grain yield (17.2%, 29.5%), DM (35.8%, 44.6%) and N (42.5%, 52.4%) accumulation, and decreased grain moisture content compared with Z. The Pn, Tr increased under ZP2 and ZP3. Moreover, the ZP2 and ZP3 treatments improved the activities of RuBPCase, PEPCase; NR, GS, GOGAT; SOD, CAT, POD in ear leaves, and decreased MDA content during grain filling stage. The results also showed the mitigative effect of ZP3 was greater than ZP2, and the improvement effect was more significant on JKN2000.
Summary Objectives Xpert MTB/RIF (Cepheid) assay has been introduced for the diagnosis of tuberculosis (TB) and RIF-resistance. The meta-analysis was used to establish the overall accuracy of Xpert ...MTB/RIF assay for diagnosing TB and RIF-resistance. Methods Based on comprehensive searches of the Pubmed and Embase, we identified outcome data from all articles estimating diagnostic accuracy with Xpert MTB/RIF assay. A summary estimation for sensitivity, specificity, diagnostic odds ratios (DOR) and the area under the summary ROC curve (AUC) was calculated by using the bivariate random-effects approach. Results The meta-analysis included 18 studies (10,224 suspected specimens). The summary estimate was 90.4% (95%CI 89.2%–91.4%) for sensitivity, 98.4% (95%CI 98.0%–98.7%) for specificity and 328.3/0.9822 for DOR/AUC in pulmonary tuberculosis (PTB). The sensitivity, specificity and DOR/AUC of detecting RIF-resistance were 94.1%, 97.0% and 177.8/0.9832, respectively. For extrapulmonary tuberculosis, the overall pooled sensitivity was 80.4% and specificity was 86.1%. The findings in subgroup analysis were as follows: the accuracy of Xpert MTB/RIF assay is higher in smear-positive specimens and the sensitivity of diagnosing PTB in adults was higher than that in children (90.8% versus 74.3%). Conclusions TB and RIF-resistance can be rapidly and effectively diagnosed with Xpert MTB/RIF assay.
A label-free and high-sensitive sensing technology for tumor cell recognition and detection was developed based on a novel 2×3 model of leaky surface acoustic wave (LSAW) aptasensor array. In this ...methodology, every resonator crystal unit of the LSAW aptasensor array had an individual oscillator circuit to work without mutual interference, and could oscillate independently with the phase shift stability of ±0.15° in air phase and ±0.3° in liquid phase. The aptamer was firstly assembled to the gold electrode surface of 100MHz LiTaO3 piezoelectric crystal, which could effectively captured target cells (MCF-7 cells) based on the specific interaction between aptamer and the overexpression of MUC1 protein on tumor cell surface. The aptamer-cell complexes increased the mass loading of LSAW aptasensor and led to phase shifts of LSAW. The plot of phase shift against the logarithm of concentration of MCF-7 cells was linear over the range from 1×102cellsmL−1 to 1×107cellsmL−1 with a correlation coefficient of 0.994. The detection limit as low as 32cellsmL−1 was achieved for MCF-7 cells. The LSAW aptasensor also exhibited excellent specificity and stability. In addition, this aptasensor could be regenerated for ten times without irreversible loss of activity. Therefore, the LSAW aptasensor may offer a promising approach for tumor cell detection and have great potential in clinical applications.
•A novel 2×3 model of LSAW aptasensor array for MCF-7 cells detection was constructed.•The phase shift was linear to the logarithm of MCF-7 cells concentration.•The LSAW aptasensor exhibited a feasible regeneration and excellent specificity.
Cancer stem cells (CSCs) are a small population of cells in tumor tissues that can drive tumor initiation and promote tumor progression. A small number of previous studies indirectly mentioned the ...role of F-box and WD repeat domain-containing 7 (FBXW7) as a tumor suppressor in Triple-negative breast cancer (TNBC). However, few studies have focused on the function of FBXW7 in cancer stemness in TNBC and the related mechanism.
We detected FBXW7 by immunohistochemistry (IHC) in 80 TNBC patients. FBXW7 knockdown and overexpression in MD-MBA-231 and HCC1937 cell models were constructed. The effect of FBXW7 on malignant phenotype and stemness was assessed by colony assays, flow cytometry, transwell assays, western blot, and sphere formation assays. Immunoprecipitation-Mass Spectrometry (IP-MS) and ubiquitination experiments were used to find and verify potential downstream substrate proteins of FBXW7. Animal experiments were constructed to examine the effect of FBXW7 on tumorigenic potential and cancer stemness of TNBC cells in vivo.
The results showed that FBXW7 was expressed at low levels in TNBC tissues and positively correlated with prognosis of TNBC patients. In vitro, FBXW7 significantly inhibited colony formation, cell cycle progression, cell migration, EMT process, cancer stemness and promotes apoptosis. Further experiments confirmed that chromodomain-helicase-DNA-binding protein 4 (CHD4) is a novel downstream target of FBXW7 and is downregulated by FBXW7 via proteasomal degradation. Moreover, CHD4 could promote the nuclear translocation of β-catenin and reverse the inhibitory effect of FBXW7 on β-catenin, and ultimately activate the Wnt/β-catenin pathway. Rescue experiments confirmed that the FBXW7-CHD4-Wnt/β-catenin axis was involved in regulating the maintenance of CSC in TNBC cells. In animal experiments, FBXW7 reduced CSC marker expression and suppressed TNBC cell tumorigenesis in vivo.
Taken together, these results highlight that FBXW7 degrades CHD4 protein through ubiquitination, thereby blocking the activation of the Wnt/β-catenin pathway to inhibit the stemness of TNBC cells. Thus, targeting FBXW7 may be a promising strategy for therapeutic intervention against TNBC.
Risk for Ovarian Malignancy Algorithm (ROMA) and Human epididymis protein 4 (HE4) appear to be promising predictors for epithelial ovarian cancer (EOC), however, conflicting results exist in the ...diagnostic performance comparison among ROMA, HE4 and CA125.
Remote databases (MEDLINE/PUBMED, EMBASE, Web of Science, Google Scholar, the Cochrane Library and ClinicalTrials.gov) and full texts bibliography were searched for relevant abstracts. All studies included were closely assessed with the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies-2). EOC predictive value of ROMA was systematically evaluated, and comparison among the predictive performances of ROMA, HE4 and CA125 were conducted within the same population. Sensitivity, specificity, DOR (diagnostic odds ratio), LR ± (positive and negative likelihood ratio) and AUC (area under receiver operating characteristic-curve) were summarized with a bivariate model. Subgroup analysis and sensitivity analysis were used to explore the heterogeneity.
Data of 7792 tests were retrieved from 11 studies. The overall estimates of ROMA for EOC predicting were: sensitivity (0.89, 95% CI 0.84-0.93), specificity (0.83, 95% CI 0.77-0.88), and AUC (0.93, 95% CI 0.90-0.95). Comparison of EOC predictive value between HE4 and CA125 found, specificity: HE4 (0.93, 95% CI 0.87-0.96) > CA125 (0.84, 95% CI 0.76-0.90); AUC: CA125 (0.88, 95% CI 0.85-0.91) > HE4 (0.82, 95% CI 0.78-0.85). Comparison of OC predictive value between HE4 and CA125 found, AUC: CA125 (0.89, 95% CI 0.85-0.91) > HE4 (0.79, 95% CI 0.76-0.83). Comparison among the three tests for EOC prediction found, sensitivity: ROMA (0.86, 95%CI 0.81-0.91) > HE4 (0.80, 95% CI 0.73-0.85); specificity: HE4 (0.94, 95% CI 0.90-0.96) > ROMA (0.84, 95% CI 0.79-0.88) > CA125 (0.78, 95%CI 0.73-0.83).
ROMA is helpful for distinguishing epithelial ovarian cancer from benign pelvic mass. HE4 is not better than CA125 either for EOC or OC prediction. ROMA is promising predictors of epithelial ovarian cancer to replace CA125, but its utilization requires further exploration.
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