A tree peony RING-H2 finger protein, PsATL33, plays an essential role in cold-induced bud dormancy release by regulating gibberellin content.

Bud dormancy is crucial for woody perennial plants to resist low-temperature stress in winter. However, the molecular regulatory mechanisms underlying bud dormancy release are largely unclear. Here, a tree peony (Paeonia suffruticosa) transcript ARABIDOPSIS TOXICOS EN LEVADURA 33 (PsATL33), encoding a RING-H2 finger protein, was selected from previously generated RNA sequencing data of chilling-treated buds. The objective of this study is to investigate the role of PsATL33 in the regulation of cold-induced bud dormancy release. Subcellular localization assay revealed that PsATL33 was localized to the nucleus and plasma membrane. Reverse transcription-quantitative PCR analysis showed that PsATL33 was dramatically upregulated during cold-triggered bud dormancy release. Exogenous treatments with gibberellin (GA3) increased, but abscisic acid (ABA) inhibited the transcription of PsATL33. Ectopic transformation assay indicated that overexpression of PsATL33 in petunia promoted seed germination, plant growth, and axillary bud break. Silencing of PsATL33 in tree peony through virus-induced gene silencing assay delayed bud dormancy release. tobacco rattle virus (TRV)-PsATL33-infected buds exhibited reduced expression levels of dormancy break-related genes EARLY BUD-BREAK 1 (PsEBB1) and CARBOXYLESTERASE 15 (PsCXE15). Silencing of PsATL33 decreased the accumulation of bioactive GAs, GA1 and GA3, rather than ABA. Transcript levels of several genes involved in GA biosynthesis and signaling, including GA20-OXIDASE 1 (PsGA20ox1), GA3-OXIDASE 1 (PsGA3ox1), PsGA3ox3, GA2-OXIDASE 1 (PsGA2ox1), and GA-INSENSITIVE 1A (PsGAI1A), were changed by PsATL33 silencing. Taken together, our data suggest that PsATL33 functions as a positive regulator of cold-induced bud dormancy release by modulating GA production.

A petunia transcription factor, PhOBF1, regulates flower senescence by modulating gibberellin biosynthesis.

Flower senescence is commonly enhanced by the endogenous hormone ethylene and suppressed by the gibberellins (GAs) in plants. However, the detailed mechanisms for the antagonism of these hormones during flower senescence remain elusive. In this study, we characterized one up-regulated gene PhOBF1, belonging to the basic leucine zipper transcription factor family, in senescing petals of petunia (Petunia hybrida). Exogenous treatments with ethylene and GA3 provoked a dramatic increase in PhOBF1 transcripts. Compared with wild-type plants, PhOBF1-RNAi transgenic petunia plants exhibited shortened flower longevity, while overexpression of PhOBF1 resulted in delayed flower senescence. Transcript abundances of two senescence-related genes PhSAG12 and PhSAG29 were higher in PhOBF1-silenced plants but lower in PhOBF1-overexpressing plants. Silencing and overexpression of PhOBF1 affected expression levels of a few genes involved in the GA biosynthesis and signaling pathways, as well as accumulation levels of bioactive GAs GA1 and GA3. Application of GA3 restored the accelerated petal senescence to normal levels in PhOBF1-RNAi transgenic petunia lines, and reduced ethylene release and transcription of three ethylene biosynthetic genes PhACO1, PhACS1, and PhACS2. Moreover, PhOBF1 was observed to specifically bind to the PhGA20ox3 promoter containing a G-box motif. Transient silencing of PhGA20ox3 in petunia plants through tobacco rattle virus-based virus-induced gene silencing method led to accelerated corolla senescence. Our results suggest that PhOBF1 functions as a negative regulator of ethylene-mediated flower senescence by modulating the GA production.

Extensive cytokine biomarker analysis in serum of Guillain-Barré syndrome patients.

Guillain-Barré syndrome (GBS) is an acute idiopathic polyneuropathy which is related to infection and immune mechanism. The exact pathogenesis of the disease is unknown and treatment is limited. Thus, the purpose of the study is to identify biomarkers of GBS serum and elucidate their involvement in the underlying pathogenesis of GBS that could help to treat GBS more accurately. Antibody array technology was used to detect the expression levels of 440 proteins in serum of 5 GBS group and 5 healthy control group. Sixty-seven differentially expressed proteins (DEPs) were identified by antibody array, among which FoLR1, Legumain, ErbB4, IL-1α, MIP-1α and IGF-2 were down-regulated, while 61 proteins were up-regulated. Bioinformatics analysis indicated that most DEPs were associated with leukocytes, among which IL-1α, SDF-1b, B7-1, CD40, CTLA4, IL-9, MIP-1α and CD40L were in the center of protein-protein interaction (PPI) network. Subsequently, the ability of these DEPs to distinguish GBS from healthy control was further evaluated. CD23 was identified by means of Random Forests Analysis (RFA) and verified by enzyme-linked immunosorbent assay (ELISA). The ROC curve result of CD23 respectively displayed that its sensitivity, specificity and AUC were 0.818, 0.800 and 0.824. We speculate that activation of leukocyte proliferation and migration in circulating blood might be associated with inflammatory recruitment of peripheral nerves, leading to the occurrence and development of GBS, but this conclusion still requires deeper confirmation. More importantly, central proteins may play a pivotal role in the pathogenesis of GBS. In addition, we detected IL-1α, IL-9, and CD23 in the serum of GBS patients for the first time, which may be promising biomarkers for the treatment of GBS.

Simultaneous influence of light and CO2 on phytoremediation performance and physiological response of plants to formaldehyde.

Phytoremediation technology is an effective method to remove formaldehyde indoors, but the purification capacity and physiological response of plants to formaldehyde under the simultaneous influence of light and CO2 have not been examined in previous studies. In this study, formaldehyde fumigation experiments were conducted on the C3 plants Epipremnum aureum A. and Chlorophytum comosum L., and the crassulacean acid metabolism (CAM) plant Dieffenbachia maculate A. The phytoremediation performance and physiological response of plants were studied. The initial concentration of formaldehyde was established at 11.950 ± 1.442 [Formula: see text]; the light intensities were 448 ± 7 [Formula: see text], 1628 ± 22 [Formula: see text], and 3259 ± 22 [Formula: see text], respectively; and the concentrations of CO2 were 455 ± 29 [Formula: see text], 978 ± 50 [Formula: see text], 2020 ± 66 [Formula: see text], and 3006 ± 95 [Formula: see text], respectively. The results indicated that the highest purification rates of formaldehyde by E. aureum, D. maculata, and C. comosum were 55.8%, 43.7%, and 53.2%, respectively. The light intensity had a positive effect on the formaldehyde purification rates of all three plants and positively stimulated peroxidase (POD) activity, while the CO2 concentration had no significant impact on the formaldehyde purification capacity and plants' physiological characteristics. Exposure to formaldehyde inhibited formaldehyde dehydrogenase (FADH) activity and positively stimulated catalase (CAT) activity. The superoxide dismutase (SOD) activity positively correlated with the formaldehyde purification capacity of plants.

Transcriptome Profiling Reveals a Petunia Transcription Factor, PhCOL4, Contributing to Antiviral RNA Silencing.

RNA silencing is a common antiviral mechanism in eukaryotic organisms. However, the transcriptional regulatory mechanism that controls the RNA silencing process remains elusive. Here, we performed high-depth transcriptome analysis on petunia (Petunia hybrida) leaves infected with tobacco rattle virus (TRV) strain PPK20. A total of 7,402 differentially expressed genes (DEGs) were identified. Of them, some RNA silencing-related transcripts, such as RNA-dependent RNA polymerases (RDRs), Dicer-like RNase III enzymes (DCLs), and Argonautes (AGOs), were induced by viral attack. Furthermore, we performed TRV-based virus-induced gene silencing (VIGS) assay on 39 DEGs encoding putative transcription factors (TFs), using green fluorescent protein (GFP) and phytoene desaturase (PhPDS) as reporters. Results showed that the down-regulation of PhbHLH41, PhbHLH93, PhZPT4-3, PhCOL4, PhHSF-B3A, PhNAC90, and PhWRKY75 led to enhanced TRV accumulation and inhibited PhPDS-silenced photobleaching phenotype. In contrast, silencing of PhERF22 repressed virus accumulation and promoted photobleaching development. Thus, these TFs were identified as potential positive and negative regulators of antiviral RNA silencing, respectively. One positive regulator PhCOL4, belonging to the B-box zinc finger family, was selected for further functional characterization. Silencing and transient overexpression of PhCOL4 resulted in decreased and increased expression of several RNA silencing-related genes. DNA affinity purification sequencing analysis revealed that PhCOL4 targeted PhRDR6 and PhAGO4. Dual luciferase and yeast one-hybrid assays determined the binding of PhCOL4 to the PhRDR6 and PhAGO4 promoters. Our findings suggest that TRV-GFP-PhPDS-based VIGS could be helpful to identify transcriptional regulators of antiviral RNA silencing.

Material Extrusion Based Fabrication of Surgical Implant Template and Accuracy Analysis.

An implant template with great precision is significantly critical for clinical application. Currently, the application of an immediate implant remains limited by the deviations between the planned and actual achieved positions and long periods required for preparation of implant templates. Material Extrusion (MEX), as one kind of 3D printing method, is well known for its low cost and easy operation. However, the accuracy of the implant template printed by MEX has not been fully researched. To investigate the accuracy and feasibility of in vitro computer-guided surgery assisted with a MEX printed template, unidentified plaster samples missing a maxillary molar are digitalized. Mimics software (Materialise, Leuven, Belgium) is used for preoperative design. Surgical templates are fabricated by a MEX 3D printer (Lingtong III, Beijing SHINO, Beijing, China). Postoperative CBCT data are obtained after surgical template placement. The differences in positions of X, Y, Z, and dXYZ as well as angulations between the placed and the designed template are measured on labiolingual and mesiodistal planes. The deviations of the planned and the actual outcome in each dimension are observed and analyzed. Data from different samples indicate that the mean deviation of the angle measures approximately 3.640°. For position deviation, the maximum deviation is found in the z-direction and the mean deviation is about 0.365 ± 0.136 mm. The mean deviation of space Euclidean distance dXYZ is approximately 0.537 ± 0.123 mm. Implant templates fabricated by MEX present a relatively high accuracy for tooth-supported guide implantation.

Corrigendum: A Tree Peony Trihelix Transcription Factor PrASIL1 Represses Seed Oil Accumulation.

[This corrects the article DOI: 10.3389/fpls.2021.796181.].

Phytoremediation of formaldehyde by the stems of Epipremnum aureum and Rohdea japonica.

Decorative plants can efficiently purify formaldehyde and improve the quality of indoor air. The existing studies primarily revealed that the aerial and underground parts of plants' capacity to purify formaldehyde, while the performance of stems is unclear. A formaldehyde fumigation experiment was conducted on Epipremnum aureum and Rohdea japonica in a sealed chamber. Results showed the stems could remove formaldehyde. The efficiency of removal by the stems of each plant was 0.089 and 0.137 mg∙m-3∙h-1, respectively, the rate of purification was 40.0 and 61.6%, respectively. Both were related to plant species and the latter was affected by other factors like exposed area. To further explore the mechanism of phytoremediation, the correlation between the concentration of formaldehyde and CO2 during the experiment was investigated. Results showed when leaves of plants were exposed to formaldehyde, the concentration of CO2 increased with the decrease in concentration of formaldehyde, and the change in concentration of CO2 could be used as an indicator of the degree of decontamination of formaldehyde by the plants.

A Tree Peony Trihelix Transcription Factor PrASIL1 Represses Seed Oil Accumulation.

In many higher plants, seed oil accumulation is governed by complex multilevel regulatory networks including transcriptional regulation, which primarily affects fatty acid biosynthesis. Tree peony (Paeonia rockii), a perennial deciduous shrub endemic to China is notable for its seed oil that is abundant in unsaturated fatty acids. We discovered that a tree peony trihelix transcription factor, PrASIL1, localized in the nucleus, is expressed predominantly in developing seeds during maturation. Ectopic overexpression of PrASIL1 in Nicotiana benthamiana leaf tissue and Arabidopsis thaliana seeds significantly reduced total fatty acids and altered the fatty acid composition. These changes were in turn associated with the decreased expression of multitudinous genes involved in plastidial fatty acid synthesis and oil accumulation. Thus, we inferred that PrASIL1 is a critical transcription factor that represses oil accumulation by down-regulating numerous key genes during seed oil biosynthesis. In contrary, up-regulation of oil biosynthesis genes and a significant increase in total lipids and several major fatty acids were observed in PrASIL1-silenced tree peony leaves. Together, these results provide insights into the role of trihelix transcription factor PrASIL1 in controlling seed oil accumulation. PrASIL1 can be targeted potentially for oil enhancement in tree peony and other crops through gene manipulation.

Effects of Antarctic krill docosahexaenoic acid on MCF-7 cell migration and invasion induced by the interaction of CD95 with caveolin-1.

Tumor metastasis leads to a poor prognosis in breast cancer, yet the mechanisms remain unclear. Docosahexaenoic acid (DHA) extracted from Antarctic krill is an optical isomer of common DHA and has a much stronger anti-neoplastic effect. In this work, the migration and invasion abilities of MCF-7 cells treated with low concentrations of Antarctic krill DHA were evaluated. Low concentrations of Antarctic krill DHA significantly reduced the numbers of migrating and invasive MCF-7 cells, whereas the cell numbers decreased slowly in the CD95-silenced MCF-7 cells, which implies that CD95 might be involved in cell migration and invasion. Additionally, co-immunoprecipitation and Western blotting demonstrated that Antarctic krill DHA induced the accumulation of CD95 and caveolin-1 interaction, resulting in the down-regulation of MMP2 expression through the FAK/SRC/PI3K/AKT signaling pathway. In conclusion, Antarctic krill DHA enhanced the interaction between CD95 and caveolin-1, which may led to an inhibitory effect on cell migration and invasion via the FAK/SRC/PI3K/AKT signaling pathway. Our study indicates that Antarctic krill DHA has great potential for tumor therapy and has revealed a new metastatic mechanism mediated by the interaction of CD95 with caveolin-1.

miR-127 contributes to ventilator-induced lung injury.

Although it is essential in critical care medicine, mechanical ventilation often results in ventilator­induced lung injury (VILI). Treating mice with lipopolysaccharide has been reported to upregulate the expression of miR­127, which has been implicated in the modulation of immune responses. However, the putative roles of miR­127 during the development of VILI have yet to be elucidated. The present study demonstrated that challenging mice with mechanical ventilation for 6 h significantly upregulated the expression of miR­127 in bronchoalveolar lavage fluid, serum and lung tissue samples. Conversely, following the downregulation of miR­127 expression in vivo using an adenovirus delivery system, VILI­associated pathologies, including alterations in the pulmonary wet/dry ratio, pulmonary permeability, lung neutrophil infiltration and levels of pro­inflammatory cytokines, were significantly attenuated. In addition, miR­127 knockdown inhibited the ventilation­induced activation of nuclear factor (NF)­κB and p38 mitogen­activated protein kinase (MAPK). These findings suggested that the upregulation of miR­127 expression may contribute to the development of VILI, through the modulation of pulmonary permeability, the induction of histopathological alterations, and the potentiation of inflammatory responses involving NF­κB and p38 MAPK­associated signaling pathways.

High frequency of LMAN1 abnormalities in colorectal tumors with microsatellite instability.

Glycosyl epitopes have been identified as tumor-specific markers in colorectal tumors and various lines of evidence indicate the significance of altered synthesis, transport, and secretion of glycoproteins in tumorigenesis. However, aberrant glycosylation has been largely ignored in microsatellite unstable (MSI-H) colorectal tumors. Therefore, we analyzed mutation frequencies of genes of the cellular glycosylation machinery in MSI-H tumors, focusing on frameshift mutations in coding MNRs (cMNRs). Among 28 candidate genes, LMAN1/ERGIC53, a mannose-specific lectin mediating endoplasmatic reticulum (ER)-to-Golgi transit of glycosylated proteins, showed high mutation frequency in MSI-H colorectal cancer cell lines (52%; 12 of 23), carcinomas (45%; 72 of 161), and adenomas (40%; 8 of 20). Biallelic mutations were observed in 17% (4 of 23) of MSI-H colorectal cancer cell lines. LMAN1 was found to be transcribed but truncated protein remained undetectable in these LMAN1-mutant cell lines. Immunohistochemical and molecular analysis of LMAN1-mutated carcinomas and adenomas revealed regional loss of LMAN1 expression due to biallelic LMAN1 cMNR frameshift mutations. In LMAN1-deficient colorectal cancer cell lines, secretion of the LMAN1 client protein alpha-1-antitrypsin (A1AT), an inhibitor of angiogenesis and tumor growth, was significantly impaired but could be restored upon LMAN1 re-expression. These results suggest that LMAN1 mutational inactivation is a frequent and early event potentially contributing to MSI-H tumorigenesis.