Plants emit a variety of volatiles in response to herbivore attack, and (Z)‐3‐hexenol and its glycosides have been shown to function as defence compounds. Although the ability to incorporate and convert (Z)‐3‐hexenol to glycosides is widely conserved in plants, the enzymes responsible for the glycosylation of (Z)‐3‐hexenol remained unknown until today. In this study, uridine‐diphosphate‐dependent glycosyltransferase (UGT) candidate genes were selected by correlation analysis and their response to airborne (Z)‐3‐hexenol, which has been shown to be taken up by the tea plant. The allelic proteins UGT85A53‐1 and UGT85A53‐2 showed the highest activity towards (Z)‐3‐hexenol and are distinct from UGT85A53‐3, which displayed a similar catalytic efficiency for (Z)‐3‐hexenol and nerol. A single amino acid exchange E59D enhanced the activity towards (Z)‐3‐hexenol, whereas a L445M mutation reduced the catalytic activity towards all substrates tested. Transient overexpression of CsUGT85A53‐1 in tobacco significantly increased the level of (Z)‐3‐hexenyl glucoside. The functional characterization of CsUGT85A53 as a (Z)‐3‐hexenol UGT not only provides the foundation for the biotechnological production of (Z)‐3‐hexenyl glucoside but also delivers insights for the development of novel insect pest control strategies in tea plant and might be generally applicable to other plants.

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4-Hydroxy-2,5-dimethylfuran-3(2H)-one (HDMF) is an important odorant in some fruits, and is proposed to play a crucial role in the caramel-like notes of some teas. However, its biosynthesis and metabolism in tea plants are still unknown. Here, HDMF glucoside was unambiguously identified as a native metabolite in tea plants. A novel glucosyltransferase UGT74AF3a and its allelic protein UGT74AF3b specifically catalyzed the glucosylation of HDMF and the commercially important structural homologues 2 (or 5)-ethyl-4-hydroxy-5 (or 2)-methylfuran-3(2H)-one (EHMF) and 4-hydroxy-5methylfuran-3(2H)-one (HMF) to their corresponding β-D-glucosides. Site-directed mutagenesis of UGT74AF3b to introduce a single A456V mutation resulted in improved HDMF and EHMF glucosylation activity and affected the sugar donor preference compared with that of the wild-type control enzyme. The accumulation of HDMF glucoside was consistent with the transcript levels of UGT74AF3 in different tea cultivars. In addition, transient UGT74AF3a overexpression in tobacco significantly increased the HDMF glucoside contents, and downregulation of UGT74AF3 transcripts in tea leaves significantly reduced the concentration of HDMF glucoside compared with the levels in the controls. The identification of HDMF glucoside in the tea plant and the discovery of a novel-specific UDP-glucose:HDMF glucosyltransferase in tea plants provide the foundation for improvement of tea flavor and the biotechnological production of HDMF glucoside.

Background: Sarcopenia, or skeletal muscle depletion, was common in the elderly and often led to a poor prognosis of diseases. The area of the psoas muscle in abdominal computed tomography (CT) is the most common used for diagnosing sarcopenia. However, patients with pneumonia routinely only undergo chest CT.Objectives: This study aimed to determine whether paraspinal muscle area (PMA) obtained by chest CT can predict death for community-acquired pneumonia (SCAP) patients entering intensive care unit (ICU). Methods: This study enrolled 208 SCAP patients admitted to ICU after undergoing chest CT. PMA, paraspinal muscle radiodensity (PMD), and lean paraspinal muscle area (LPMA) were calculated on chest CT images. The main outcome was mortality during hospitalization. Logistic regression, receiver operating characteristic (ROC) curve, and Kaplan-Meier curves were used to evaluate forecasting effectiveness. Results: The primary outcome occurred in 76 (36.53%) patients. In multivariate logistic regression, PMA, lactic dehydrogenase (LDH), invasive mechanical ventilation (IMV), red blood cell (RBC) and age 65 years were independent risk factors predicting death during hospitalization (adjusted Odds Ratio [OR]: 0.886, 1.002, 3.178, 0.612 and 2.003, respectively). The area under curve (AUC) of PMA to predict death was 0.720 (P< 0.001). During hospitalization, the median survival time of high-PMA (51.00 days) and low-PMA groups (20.00 days) was statistically significant (P< 0.001). Conclusion: Lower PMA was associated with an increased risk of death for SCAP patients admitted to the ICU. In other words, PMA may help early identify adverse prognosis of SCAP patients admitted to ICU.

In this article, we report a tungsten disulphide (WS2) nanosheet sensing platform based on chemiluminescence resonance energy transfer (CRET) for light on detection of ochratoxin A (OTA). The CRET system involves OTA aptamer-12-mer linker-DNAzyme, phosphate-DNA, lambda exonuclease (λexo), hemin, H2O2, luminol and a WS2 nanosheet. Based on the change in chemiluminescence intensity resulting from the OTA aptamer-12-mer linker-G-Quadruplexes/Hemin DNAzymes affinity for or desorption from the WS2 nanosheet surface in the presence and absence of OTA, an ultra-sensitive CRET-based sensor system is proposed, in which the OTA aptamer-12-mer linker-G-Quadruplexes/Hemin DNAzymes–H2O2–luminol and WS2 nanosheets act as CRET donors and acceptors, respectively. Various factors affecting the detection of OTA, including the incubation time of the OTA aptamer-12 mer linker-G-Quadruplexes/Hemin DNAzyme and WS2 nanosheet, the amount of λexo, concentrations of the WS2 nanosheet, luminol and H2O2, and pH value of the chemiluminescence reaction solution were investigated in detail. Under the optimal experimental conditions, the relative luminesecence intensity of the sensing system exhibited a good linear correlation with the OTA concentration in the range of 1.0–10.0 ng mL–1 with a LOD of 0.13 ng mL–1. The proposed CRET-based sensing system also exhibited excellent recoveries of 85.7–93.0% in rice samples and showed good application prospects for the analysis and detection of OTA, which is also easily extended to assay other biomolecules by simply changing the recognition sequence with the substrate aptamer.