•Microbial fermentation is the key factor controlling the quality of dark tea.•Serial reactions modify the chemical constituents of tea leaves during fermentation.•Multi-omics approaches are used to ...reveal microbial impact on dark tea quality.
Dark tea is a unique fermented tea produced by solid-state fermentation of tea leaves (Camellia sinensis). It includes ripe Pu-erh tea, Fu brick tea, Liupao tea, and other teas. Microbial fermentation is considered to be the key factor controlling the quality of dark tea. It involves a series of reactions that modify the chemical constituents of tea leaves. These chemical conversions during microbial fermentation of dark tea are associated with a variety of functional core microorganisms. Further, Multi-omics approaches have been used to reveal the microbial impact on the conversion of the chemical components in dark tea. In the present review, we provide an overview of the most recent advances in the knowledge of the microbial bioconversion of the chemical components in dark tea, including the chemical composition of dark tea, microbial community composition and dynamics during the fermentation process, and the role of microorganisms in biotransformation of chemical constituents.
Fractional oscillators can effectively deal with noise in the vibration. This paper adopts He’s fractional derivative, which is defined through the variational iteration algorithm. Ji-Huan He’s ...amplitude–frequency formulation is used to solve the fractional Duffing equation.
Clinical therapy of doxorubicin (DOX) is limited due to its cardiotoxicity. miR-146a was proved as a protective factor in many cardiovascular diseases, but its role in chronic DOX-induced ...cardiotoxicity is unclear. The objective of this study was to demonstrate the role of miR-146a in low-dose long-term DOX-induced cardiotoxicity. Experiments have shown that DOX intervention caused a dose-dependent and time-dependent cardiotoxicity involving the increased of apoptosis and dysregulation of autophagy. The cardiotoxicity was inhibited by overexpressed miR-146a and was more severe when miR-146a was downgraded. Further research proved that miR-146a targeted TATA-binding protein (TBP) associated factor 9b (TAF9b), a coactivator and stabilizer of P53, indirectly destroyed the stability of P53, thereby inhibiting apoptosis and improving autophagy in cardiomyocytes. Besides, miR-146a knockout mice were used for in vivo validation. In the DOX-induced model, miR-146a deficiency made it worse whether in cardiac function, cardiomyocyte apoptosis or basal level of autophagy, than wild-type. In conclusion, miR-146a partially reversed the DOX-induced cardiotoxicity by targeting TAF9b/P53 pathway to attenuate apoptosis and adjust autophagy levels.
SUMMARY
Drought stress induces anthocyanin biosynthesis in many plant species, but the underlying molecular mechanism remains unclear. Ethylene response factors (ERFs) play key roles in plant growth ...and various stress responses, including affecting anthocyanin biosynthesis. Here, we characterized an ERF protein, MdERF38, which is involved in drought stress‐induced anthocyanin biosynthesis. Biochemical and molecular analyses showed that MdERF38 interacted with MdMYB1, a positive modulator of anthocyanin biosynthesis, and facilitated the binding of MdMYB1 to its target genes. Therefore, MdERF38 promoted anthocyanin biosynthesis in response to drought stress. Furthermore, we found that MdBT2, a negative modulator of anthocyanin biosynthesis, decreased MdERF38‐promoted anthocyanin biosynthesis by accelerating the degradation of the MdERF38 protein. In summary, our data provide a mechanism for drought stress‐induced anthocyanin biosynthesis that involves dynamic modulation of MdERF38 at both transcriptional and post‐translational levels.
Significance Statement
MdERF38 promotes anthocyanin biosynthesis by interacting with MdMYB1 and enhancing the binding of MdMYB1 to its target genes in response to drought stress. MdBT2 decreases drought‐induced anthocyanin accumulation by accelerating the degradation of MdERF38.
Summary
Cold stress severely affects plant growth and yield. C‐repeat binding factors (CBFs) play important roles in the response to cold stress. In the present study, we identified an R2R3‐MYB ...transcription factor (TF) MdMYB23 from apple (Malus × domestic) using transcriptome analyses, which was notably induced in response to cold stress. Transgenic apple calli and Arabidopsis with overexpression of MdMYB23 exhibited increased cold tolerance. Electrophoretic mobility shift assay (EMSA) and transient expression assays indicated that MdMYB23 directly bound to the promoters of MdCBF1 and MdCBF2 and activated their expression. MdMYB23 interacted with the promoter of MdANR, a key modulator of proanthocyanidin biosynthesis, and activated its expression to promote proanthocyanidin accumulation and reactive oxygen species (ROS) scavenging. MdBT2 was identified as an MdMYB23‐interacting protein using yeast two‐hybrid (Y2H), pull‐down, and bimolecular fluorescence complementation (BiFC) assays. MdBT2 repressed cold tolerance and proanthocyanidin accumulation by promoting the degradation of MdMYB23 protein. Our findings shed light on the functions of MYB TFs and underlying mechanism in the modulation of plant cold tolerance.
Significance Statement
An apple R2R3‐MYB TF MdMYB23 increases cold tolerance and proanthocyanidin accumulation by directly activating the expression of MdCBF1/2 and MdANR. MdBT2 represses cold tolerance and proanthocyanidin accumulation by promoting the degradation of MdMYB23 protein.
Summary
The plant hormone jasmonic acid (JA) is involved in the cold stress response, and the inducer of CBF expression 1 (ICE1)‐ C‐repeat binding factor (CBF) regulatory cascade plays a key role in ...the regulation of cold stress tolerance. In this study, we showed that a novel B‐box (BBX) protein MdBBX37 positively regulates JA‐mediated cold‐stress resistance in apple.
We found that MdBBX37 bound to the MdCBF1 and MdCBF4 promoters to activate their transcription, and also interacted with MdICE1 to enhance the transcriptional activity of MdICE1 on MdCBF1, thus promoting its cold tolerance.
Two JA signaling repressors, MdJAZ1 and MdJAZ2 (JAZ, JAZMONATE ZIM‐DOMAIN), interacted with MdBBX37 to repress the transcriptional activity of MdBBX37 on MdCBF1 and MdCBF4, and also interfered with the interaction between MdBBX37 and MdICE1, thus negatively regulating JA‐mediated cold tolerance. E3 ligase MdMIEL1 (MIEL1, MYB30‐Interacting E3 Ligase1) reduced MdBBX37‐improved cold resistance by mediating ubiquitination and degradation of the MdBBX37 protein.
The data reveal that MIEL1 and JAZ proteins co‐regulate JA‐mediated cold stress tolerance through the BBX37‐ICE1‐CBF module in apple. These results will aid further examination of the post‐translational modification of BBX proteins and the regulatory mechanism of JA‐mediated cold stress tolerance.
Critical patients with the coronavirus disease 2019 (COVID-19), even those whose nucleic acid test results had turned negative and those receiving maximal medical support, have been noted to progress ...to irreversible fatal respiratory failure. Lung transplantation (LT) as the sole therapy for end-stage pulmonary fibrosis related to acute respiratory distress syndrome has been considered as the ultimate rescue therapy for these patients.
From February 10 to March 10, 2020, three male patients were urgently assessed and listed for transplantation. After conducting a full ethical review and after obtaining assent from the family of the patients, we performed three LT procedures for COVID-19 patients with illness durations of more than one month and extremely high sequential organ failure assessment scores.
Two of the three recipients survived post-LT and started participating in a rehabilitation program. Pearls of the LT team collaboration and perioperative logistics were summarized and continually improved. The pathological results of the explanted lungs were concordant with the critical clinical manifestation, and provided insight towards better understanding of the disease. Government health affair systems, virology detection tools, and modern communication technology all play key roles towards the survival of the patients and their rehabilitation.
LT can be performed in end-stage patients with respiratory failure due to COVID-19-related pulmonary fibrosis. If confirmed positive-turned-negative virology status without organ dysfunction that could contraindicate LT, LT provided the final option for these patients to avoid certain death, with proper protection of transplant surgeons and medical staffs. By ensuring instant seamless care for both patients and medical teams, the goal of reducing the mortality rate and salvaging the lives of patients with COVID-19 can be attained.
Until now there has been no fundamental theory applicable for biodegradable metals (BMs). First, this paper optimizes the definition of BMs given in 2014. Second, the dual criteria of ...biodegradability and biocompatibility are proposed for BMs, and all metallic elements in the periodic table with accessible data are screened on the basis of these criteria. Regarding biodegradability, electrode potential, reactivity series, galvanic series, Pilling–Bedworth ratio, and Pourbaix diagrams are all adopted as parameters to classify the degradable and nondegradable nature of a material, especially in a physiological environment. Considering the biocompatibility at different levels, cellular biocompatibility, tissue biocompatibility, and human/clinical related biocompatibility parameters are put forward to comprehensively evaluate the biosafety of BMs. Third, for the material design of BMs, mechanical properties, chemical properties, physical properties and biological properties should be considered and balanced to guarantee that the degradation behavior of BMs match well with a tissue regeneration/repair procedure as the function of time and spatial location. Besides the selected metallic elements, some nonmetallic elements are selected as suitable alloying elements for BMs. Finally, five classification/research directions for future BMs are proposed: biodegradable pure metals, crystalline alloys, bulk metallic glasses, high entropy alloys, and metal matrix composites.
The fundamental theory of biodegradable metals are clarified in this review article, with the definition of biodegradable metals, biodegradability, and biocompatibility dual criteria for metallic elements in the periodic table being regarded as biodegradable metals. Key properties needed to be considered for materials design of biodegradable metals and future research and development directions for biodegradable metals are proposed.
The molecular mechanism of ABA‐promoted anthocyanin accumulation and fruit coloration is less known. Here, an apple bZIP transcription factor MdbZIP44 was identified to be a positive regulator in ...ABA‐promoted anthocyanin accumulation by interacting with MdMYB1 and enhancing its binding capacity to the promoters of downstream target genes. MdBT2 decreased ABA‐promoted anthocyanin accumulation by degrading MdbZIP44 protein.
Phytohormone abscisic acid (ABA) induces anthocyanin biosynthesis; however, the underlying molecular mechanism is less known. In this study, we found that the apple MYB transcription factor MdMYB1 activated anthocyanin biosynthesis in response to ABA. Using a yeast screening technique, we isolated MdbZIP44, an ABA‐induced bZIP transcription factor in apple, as a co‐partner with MdMYB1. MdbZIP44 promoted anthocyanin accumulation in response to ABA by enhancing the binding of MdMYB1 to the promoters of downstream target genes. Furthermore, we identified MdBT2, a BTB protein, as an MdbZIP44‐interacting protein. A series of molecular, biochemical, and genetic analysis suggested that MdBT2 degraded MdbZIP44 protein through the Ubiquitin‐26S proteasome system, thus inhibiting MdbZIP44‐modulated anthocyanin biosynthesis. Taken together, we reveal a novel working mechanism of MdbZIP44‐mediated anthocyanin biosynthesis in response to ABA.
Wounding stress leads to anthocyanin accumulation. However, the underlying molecular mechanism remains elusive. In this study, MdWRKY40 was found to promote wounding-induced anthocyanin biosynthesis ...in association with MdMYB1 and undergo MdBT2-mediated degradation in apple.
We found that MdMYB1, a positive regulator of anthocyanin biosynthesis, was essential for the wounding-induced anthocyanin biosynthesis in apple. MdWRKY40 was identified as an MdMYB1-interacting protein, and enhanced the binding of MdMYB1 to its target genes in response to wounding.
We found that MdBT2 interacted physically with MdWRKY40 and was involved in its degradation through the 26S proteasome pathway.
Our results demonstrate that MdWRKY40 is a key modulator in the wounding-induced anthocyanin biosynthesis, which provides new insights into the regulation of wounding-induced anthocyanin biosynthesis at both the transcriptional and post-translational levels in apple.
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