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1.
South Asian J Cancer ; 12(2): 126-134, 2023 Apr.
Article in English | MEDLINE | ID: mdl-37969675

ABSTRACT

Hao DingBackground This study aimed to screen potential key genes associated with lipid metabolism and to evaluate their expressions and prognosis values in hepatocellular carcinoma (HCC). Methods Data sets GSE6764, GSE14520, and GSE112790 were used to identify the common differentially expressed genes (DEGs). Protein-protein interaction (PPI) network was constructed by STRING database. Hub genes in PPI network were identified and subjected to functional enrichment analysis to screen lipid metabolism-related genes. The expressions of selected genes and their associations with prognosis were analyzed using UALCAN, The Human Protein Atlas, and Kaplan-Meier plotter databases. The transcriptional factor (TF)-gene regulatory network was constructed using NetworkAnalyst. Results A total of 331 common DEGs including 106 upregulated and 225 downregulated genes were identified. PPI network analysis showed that 76 genes with high degrees were identified as hub genes, among which 14 genes were lipid metabolism-related genes. PON1, CYP2C9, and SPP1 were found to be the independent prognostic markers. Key TFs with close interactions with these prognostic genes, including HINFP, SRF, YY1, and NR3C1, were identified from the TF-gene regulatory network. Conclusion This study presented evidence for the prognostic capabilities of lipid metabolism-related genes in HCC, and newly identified HINFP and NR3C1 as potential biomarkers for HCC.

2.
Front Hum Neurosci ; 17: 1095431, 2023.
Article in English | MEDLINE | ID: mdl-37576471

ABSTRACT

Purpose: To assess the interhemispheric homotopic connectivity alterations in patients with comitant exotropia (CE) before and after surgery, using resting-state functional magnetic resonance imaging (rs-fMRI) with voxel-mirrored homotopic connectivity (VMHC). Methods: Thirty-four patients with CE and twenty-four well-matched healthy controls (HCs) were enrolled to undergo a preoperative rs-fMRI scan. The rs-fMRI scan was performed again in twenty-four patients 1 month after surgery. The VMHC method was applied to evaluate the group differences of interhemispheric functional connectivity. The correlations between VMHC values and clinical variables were analyzed in the patient group. Results: Compared with HCs, 34 patients with CE showed significantly increased VMHC values in occipital lobe (cuneus/superior occipital gyrus/middle occipital gyrus/calcarine), cerebellar area 8/cerebellar Crus1 area, and cerebellar Crus1 area. In CE group, VMHC in the cuneus was positively correlated with stereoacuity (r = 0.417, P = 0.014), meanwhile VMHC in the cerebellar Crus1 area was positively correlated with stereoacuity (r = 0.395, P = 0.021). One month after surgery, the 24 CE patients with follow-up showed decreased VMHC values in the cuneus and superior occipital gyrus compared with preoperative collection, meanwhile, non-significant difference compared with HCs. Conclusion: Our study revealed the interhemispheric homotopic connectivity changes of patients with CE in the occipital lobe and cerebellum before and after surgery. The findings may provide a new perspective for the neurological alterations of CE.

3.
Molecules ; 28(6)2023 Mar 13.
Article in English | MEDLINE | ID: mdl-36985565

ABSTRACT

The development of Dai medicine is relatively slow, and Zanthoxylum has great economic and medicinal value. It is still difficult to obtain medicinal components from the low-polarity parts of Zanthoxylum belonging to Dai medicine. In this study, we introduced one simple and quick strategy of separating target compounds from the barks of Z. acanthopodium var. timbor by high-performance countercurrent chromatography (HPCCC) with an off-line anti-inflammatory activity screening mode. The development of this strategy was based on the TLC-based generally useful estimation of solvent systems (GUESS) method and HPCCC in combination. This paper presented a rapid method for obtaining target anti-inflammatory compounds. Three lignins were enriched by HPCCC with an off-line inhibition mode of nitric oxide production in lipopolysaccharide-stimulated RAW264.7 macrophage cells, using petroleum ether-ethyl acetate-methanol-water (3:2:3:2) as the solvent system. The results showed that this method was simple and practical and could be applied to trace the anti-inflammatory components of the low-polarity part in Dai medicine.


Subject(s)
Plants, Medicinal , Zanthoxylum , Countercurrent Distribution/methods , Lignin/pharmacology , Lignin/analysis , Zanthoxylum/chemistry , Chromatography, High Pressure Liquid/methods , Anti-Inflammatory Agents/pharmacology , Solvents , Plant Extracts/chemistry
4.
Hortic Res ; 10(3): uhad008, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36960429

ABSTRACT

Grafting facilitates the interaction between heterologous cells with different genomes, resulting in abundant phenotypic variation, which provides opportunities for crop improvement. However, how grafting-induced variation occurs and is transmitted to progeny remains elusive. A graft chimera, especially a periclinal chimera, which has genetically distinct cell layers throughout the plant, is an excellent model to probe the molecular mechanisms of grafting-induced variation maintenance. Here we regenerated a plant from the T-cell layer of a periclinal chimera, TCC (where the apical meristem was artificially divided into three cell layers - from outside to inside, L1, L2, and L3; T = Tuber mustard, C = red Cabbage), named rTTT0 (r = regenerated). Compared with the control (rsTTT, s = self-grafted), rTTT0 had multiple phenotypic variations, especially leaf shape variation, which could be maintained in sexual progeny. Transcriptomes were analyzed and 58 phenotypic variation-associated genes were identified. Whole-genome bisulfite sequencing analyses revealed that the methylome of rTTT0 was changed, and the CG methylation level was significantly increased by 8.74%. In rTTT0, the coding gene bodies are hypermethylated in the CG context, while their promoter regions are hypomethylated in the non-CG context. DNA methylation changes in the leaf shape variation-associated coding genes, ARF10, IAA20, ROF1, and TPR2, were maintained for five generations of rTTT0. Interestingly, grafting chimerism also affected transcription of the microRNA gene (MIR), among which the DNA methylation levels of the promoters of three MIRs associated with leaf shape variation were changed in rTTT0, and the DNA methylation modification of MIR319 was maintained to the fifth generation of selfed progeny of rTTT0 (rTTT5). These findings demonstrate that DNA methylation of coding and non-coding genes plays an important role in heterologous cell interaction-induced variation formation and its transgenerational inheritance.

5.
Org Lett ; 25(7): 1172-1177, 2023 Feb 24.
Article in English | MEDLINE | ID: mdl-36779869

ABSTRACT

Chiral benzoxazinones and 4H-3,1-benzoxazines as important motifs are widely found in abundant pharmaceuticals and biological molecules. We herein successfully developed the first kinetic resolution (KR) process of racemic benzoxazinones through Ir-catalyzed asymmetric intramolecular allylation, furnishing a wide range of chiral benzoxazinones and 4H-3,1-benzoxazines with excellent results via outstanding KR performances (with the s factor up to 170). This protocol exhibited broad substrate scope generality and good functional group tolerance, and the chiral 4H-3,1-benzoxazine products could be readily transformed to other useful optically active heterocycles.

6.
Org Lett ; 25(5): 738-743, 2023 Feb 10.
Article in English | MEDLINE | ID: mdl-36716390

ABSTRACT

Efficient Ni/(S,S)-Ph-BPE-catalyzed asymmetric hydrogenation of α-substituted α,ß-unsaturated phosphine oxides/phosphonates/phosphoric acids has been successfully developed, and a wide range of chiral α-substituted phosphines hydrogenation products were obtained in generally high yields with excellent enantioselective control (92%-99% yields, 84%->99% ee). This method features a cheap transition metal nickel catalytic system, high functional group tolerance, wide substrate scope generality, and excellent enantioselectivity. A plausible catalytic cycle was proposed for this asymmetric hydrogenation according to the results of deuterium-labeling experiments.

7.
Micromachines (Basel) ; 13(12)2022 Nov 26.
Article in English | MEDLINE | ID: mdl-36557379

ABSTRACT

With the growing demands for transferring large amounts of data between components in a package, it is required for advanced packaging technologies to form smaller vertical vias in the insulators. Plasma etching is one of the most widely used micro-vias formation processes. This paper has developed a fabrication process for 5-10 µm residue-free micro-vias with 70° tapered angle in polyimide film based on O2/CHF3 inductively coupled plasma (ICP). The etch rate would monotonically increase with the ICP power, RF power, and gas flow rate. As for the gas ratio, there is an optimum range of CHF3 ratio, which could obtain the highest etch rate. The results have clearly shown that the enhancement of ion bombardment and prolongation of etching time would be beneficial to grass-like residue removal. In addition, during the etching of partially cured polyimide, the lateral etch rate would significantly increase in the region near the metal hard mask.

8.
Exp Eye Res ; 222: 109161, 2022 09.
Article in English | MEDLINE | ID: mdl-35753431

ABSTRACT

Patients with comitant exotropia (CE) would usually develop compromised binocular vision and impaired stereoscopic depth perception, which could result in a profound decrease in quality of life. Although the deviated optic axis could be corrected surgically, the impaired stereovision and sensory eye balance may sometimes remain remnant. This study was to investigate the brain functional alterations in patients with CE before and after surgery, using resting-state functional magnetic resonance imaging (fMRI) with amplitude of low-frequency fluctuation (ALFF). Thirty-five patients with CE were recruited to undergo a preoperative fMRI scan, as well as 24 healthy controls (HCs). Twenty-four of the patients were available for rescanned fMRI one month after surgery. The ALFF method was used to evaluate the group differences of spontaneous brain activity. The correlations between ALFF values and clinical variables were analyzed in the patient group. Preoperatively, compared with HCs, 35 patients with CE showed significantly decreased ALFF values in one cluster involving bilateral calcarine sulcus, lingual gyrus and cuneus. The ALFF values in the above cluster were negatively correlated with disease duration (r = -0.379, P = 0.033). One month after surgery, 24 patients with available rescanned fMRI demonstrated increased ALFF values in one cluster located in bilateral cuneus, calcarine sulcus and lingual gyrus relative to the preoperative collection, while still reduced ALFF values in the cluster involving left calcarine sulcus and lingual gyrus compared with HCs. Our study revealed the functional changes of patients with CE in visual-associated brain areas before and after surgery. The findings may provide a new perspective for understanding the underlying pathological mechanisms of CE.


Subject(s)
Exotropia , Magnetic Resonance Imaging , Brain/diagnostic imaging , Brain Mapping/methods , Exotropia/surgery , Humans , Magnetic Resonance Imaging/methods , Quality of Life
9.
Ann Clin Lab Sci ; 51(1): 22-29, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33653777

ABSTRACT

OBJECTIVE: All-trans retinoic acid (ATRA), a derivative of vitamin A, has been reported to exert its synergistic antitumor effect with chemotherapy in various cancer types; however, its effect in cervical cancer remains unclear. The objective of this study was to investigate the antitumor effect of ATRA with or without cisplatin and elucidate its potential mechanisms in cervical cancer cells. METHODS: Cell viability was determined by CCK-8 assay. Cell cycle and cell apoptosis were analyzed by flow cytometry. Caspase-3, cleaved caspase-3 and cell cycle-related proteins were detected by western blotting. Scratch wound-healing assay was performed to evaluate cell migration ability. The expression of CD44, a biomarker of cervical cancer stem-like cells, was determined by flow cytometry and western blotting. In addition, the activity of the Wnt signaling pathway was monitored by luciferase reporter assay and western blotting. RESULTS: Compared with cisplatin treatment alone, combined use of ATRA and cisplatin significantly inhibited cell proliferation (p<0.01) and migration (p<0.01), and induced G0/G1 phase arrest (p<0.01) and apoptosis (p<0.05) in cervical cancer Hela cells. Furthermore, ATRA treatment also effectively induced differentiation of cancer stem-like cells as represented by reduced expression of CD44 and inhibited Wnt signaling pathway activity. CONCLUSIONS: ATRA significantly enhanced the antitumor effect of cisplatin in cervical cancer cells, the mechanism of which might be attributed to its effect of inducing the differentiation of cancer stem-like cells.


Subject(s)
Neoplastic Stem Cells/metabolism , Tretinoin/pharmacology , Uterine Cervical Neoplasms/metabolism , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Cell Cycle/drug effects , Cell Differentiation/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Cisplatin/pharmacology , Drug Synergism , Female , HeLa Cells , Humans , Neoplastic Stem Cells/drug effects , Signal Transduction/drug effects , Tretinoin/metabolism , Uterine Cervical Neoplasms/genetics
10.
Plant Mol Biol ; 102(1-2): 123-141, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31776846

ABSTRACT

KEY MESSAGE: Conserved motif, gene structure, expression and interaction analysis of C2H2-ZFPs in Brassica rapa, and identified types of genes may play essential roles in flower development, and BrZFP38 was proved to function in flower development by affecting pollen formation. Flower development plays a central role in determining the reproduction of higher plants, and Cys2/His2 zinc-finger proteins (C2H2-ZFPs) widely participate in the transcriptional regulation of flower development. C2H2-ZFPs with various structures are the most widespread DNA-binding transcription factors in plants. In this study, conserved protein motif and gene structures were analyzed to investigate systematically the molecular features of Brassica rapa C2H2-ZFP genes. Expression of B. rapa C2H2-ZFPs in multiple tissues showed that more than half of the family members with different types ZFs were expressed in flowers. The specific expression profiles of these C2H2-ZFPs in different B. rapa floral bud stages were further evaluated to identify their potential roles in flower development. Interaction networks were constructed in B. rapa based on the orthology of flower-related C2H2-ZFP genes in Arabidopsis. The putative cis-regulatory elements in the promoter regions of these C2H2-ZFP genes were thoroughly analyzed to elucidate their transcriptional regulation. Results showed that the orthologs of known-function flower-related C2H2-ZFP genes were conserved and differentiated in B. rapa. A C2H2-ZFP was proved to function in B. rapa flower development. Our study provides a systematic investigation of the molecular characteristics and expression profiles of C2H2-ZFPs in B. rapa and promotes further work in function and transcriptional regulation of flower development.


Subject(s)
Brassica rapa/genetics , CYS2-HIS2 Zinc Fingers/genetics , Flowers/genetics , Gene Expression Regulation, Plant , Transcription Factors/genetics , Amino Acid Motifs/genetics , Arabidopsis/genetics , Arabidopsis/metabolism , Brassica rapa/metabolism , CYS2-HIS2 Zinc Fingers/physiology , Flowers/growth & development , Gene Expression Profiling , Glucuronidase/metabolism , Phylogeny , Plant Development/genetics , Plant Development/physiology , Plant Proteins/classification , Plant Proteins/genetics , Plants, Genetically Modified , Pollen/genetics , Pollen/growth & development , Protein Interaction Maps
11.
Plant Mol Biol ; 101(6): 537-550, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31745746

ABSTRACT

KEY MESSAGE: MIR159/319 have conserved evolution and diversified function after WGT in Brassica campestris, both of them can lead pollen vitality and germination abnormality, Bra-MIR319c also can function in flower development. MiR159 and miR319 are extensively studied highly conserved microRNAs which play roles in vegetative development, reproduction, and hormone regulation. In this study, the effects of whole-genome triplication (WGT) on the evolution of the MIR159/319 family and the functional diversification of the genes were comprehensively investigated in Brassica campestris. We identified 11 MIR159/319 genes in B. campestris, which produced five mature sequences. After analyzing the precursor sequences and phylogenetic tree, we found that Bra-MIR159/319 have evolutionary conservatism. Furthermore, Bra-MIR159/319 show functional diversification after WGT, as indicated by their expression patterns and the cis-element in their promoter. GUS signal showed that Bra-MIR159a and Bra-MIR319c can be expressed in anther but in different development stages. In B. campestris, overexpressed MIR159a and MIR319c contribute to late anther development and promote pollen abortion. Moreover, Bra-MIR319c can partially assume the function of MIR319a in flower development.


Subject(s)
Brassica/metabolism , Plant Proteins/metabolism , Pollen/metabolism , Brassica/genetics , Gene Expression Regulation, Plant/genetics , Gene Expression Regulation, Plant/physiology , Plant Proteins/genetics , Pollen/genetics
12.
Biochem Biophys Res Commun ; 518(4): 726-731, 2019 10 22.
Article in English | MEDLINE | ID: mdl-31472956

ABSTRACT

In flowering plants, stamen development is a complex multistage process, which is highly regulated by a series of transcription factors. In this study, BcMF28, which encodes a R2R3-MYB transcription factor, was isolated from Brassica campestris. BcMF28 is localized in the nucleus and cytoplasm, and acts as a transcriptional activator. Quantitative real-time PCR and promoter activity analysis revealed that BcMF28 was predominately expressed in inflorescences. The expression of BcMF28 was specifically detected in tapetum, developing microspores, anther endothecium, and filaments during late stamen development. The overexpression of BcMF28 in Arabidopsis resulted in aberrant stamen development, including filament shortening, anther indehiscence, and pollen abortion. Detailed analysis of anther development in transgenic plants revealed that the degeneration of septum and stomium did not occur, and endothecium lignification was affected. Furthermore, the expression levels of genes involved in the phenylpropanoid metabolism pathway were altered in BcMF28-overexpressing transgenic plants. Our results suggest that BcMF28 plays an important regulatory role during late stamen development.


Subject(s)
Arabidopsis Proteins/genetics , Arabidopsis/genetics , Flowers/genetics , Gene Expression Regulation, Developmental , Gene Expression Regulation, Plant , Transcription Factors/genetics , Arabidopsis/growth & development , Arabidopsis/metabolism , Arabidopsis Proteins/metabolism , Flowers/growth & development , Flowers/metabolism , Plant Infertility/genetics , Plants, Genetically Modified , Pollen/genetics , Pollen/growth & development , Pollen/metabolism , Propanols/metabolism , Transcription Factors/metabolism
13.
Plant Mol Biol ; 100(1-2): 133-149, 2019 May.
Article in English | MEDLINE | ID: mdl-30843130

ABSTRACT

KEY MESSAGE: The OsPLS2 locus was isolated and cloned by map-based cloning that encodes a Upf1-like helicase. Disruption of OsPLS2 accelerated light-dependent leaf senescence in the rice mutant of ospls2. Leaf senescence is a very complex physiological process controlled by both genetic and environmental factors, however its underlying molecular mechanisms remain elusive. In this study, we report a novel Oryza sativa premature leaf senescence mutant (ospls2). Through map-based cloning, a G-to-A substitution was determined at the 1st nucleotide of the 13th intron in the OsPLS2 gene that encodes a Upf1-like helicase. This mutation prompts aberrant splicing of OsPLS2 messenger and consequent disruption of its full-length protein translation, suggesting a negative role of OsPLS2 in regulating leaf senescence. Wild-type rice accordingly displayed a progressive drop of OsPSL2 protein levels with age-dependent leaf senescence. Shading and light filtration studies showed that the ospls2 phenotype, which was characteristic of photo-oxidative stress and reactive oxygen species (ROS) accumulation, was an effect of irritation by light. When continuously exposed to far-red light, exogenous H2O2 and/or abscisic acid (ABA), the ospls2 mutant sustained hypersensitive leaf senescence. In consistence, light and ROS signal pathways in ospls2 were activated by down-regulation of phytochrome genes, and up-regulation of PHYTOCHROME-INTERACTING FACTORS (PIFs) and WRKY genes, all promoting leaf senescence. Together, these data indicated that OsPLS2 played an essential role in leaf senescence and its disruption triggered light-dependent leaf senescence in rice.


Subject(s)
DNA Helicases/genetics , Genes, Plant , Light , Oryza/growth & development , Oryza/genetics , Plant Leaves/growth & development , Plant Proteins/genetics , Abscisic Acid/metabolism , Amino Acid Sequence , Antioxidants/metabolism , DNA Helicases/chemistry , DNA Helicases/metabolism , Gene Expression Regulation, Plant , Mutation/genetics , Oryza/enzymology , Oryza/radiation effects , Phenotype , Photosynthesis/genetics , Plant Leaves/genetics , Plant Leaves/radiation effects , Plant Leaves/ultrastructure , Plant Proteins/chemistry , Plant Proteins/metabolism , Reactive Oxygen Species/metabolism , Time Factors
14.
Plant Physiol ; 179(2): 749-760, 2019 02.
Article in English | MEDLINE | ID: mdl-30563923

ABSTRACT

During the transition from warm to cool seasons, plants experience decreased temperatures, shortened days, and decreased red/far-red (R/FR) ratios of light. The mechanism by which plants integrate these environmental cues to maintain plant growth and adaptation remains poorly understood. Here, we report that low temperature induced the transcription of PHYTOCHROME A and accumulation of LONG HYPOCOTYL5 (SlHY5, a basic Leu zipper transcription factor) in tomato (Solanum lycopersicum) plants, especially under short day conditions with low R/FR light ratios. Reverse genetic approaches and physiological analyses revealed that silencing of SlHY5 increased cold susceptibility in tomato plants, whereas overexpression of SlHY5 enhanced cold tolerance. SlHY5 directly bound to and activated the transcription of genes encoding a gibberellin-inactivation enzyme, namely GIBBERELLIN2-OXIDASE4, and an abscisic acid biosynthetic enzyme, namely 9-CIS-EPOXYCAROTENOID DIOXYGENASE6 (SlNCED6). Thus, phytochrome A-dependent SlHY5 accumulation resulted in an increased abscisic acid/gibberellin ratio, which was accompanied by growth cessation and induction of cold response. Furthermore, silencing of SlNCED6 compromises short day- and low R/FR-induced tomato resistance to cold stress. These findings provide insight into the molecular genetic mechanisms by which plants integrate environmental stimuli with hormones to coordinate their growth with impending cold temperatures. Moreover, this work reveals a molecular mechanism that plants have evolved for growth and survival in response to seasonal changes.


Subject(s)
Cold-Shock Response/physiology , Plant Proteins/metabolism , Solanum lycopersicum/physiology , Abscisic Acid/metabolism , Adaptation, Physiological , Gene Expression Regulation, Plant , Gibberellins/biosynthesis , Gibberellins/metabolism , Light , Mutation , Photoperiod , Phytochrome A/metabolism , Plant Growth Regulators/metabolism , Plant Proteins/genetics , Promoter Regions, Genetic , Signal Transduction , Temperature
15.
Toxicol Res (Camb) ; 7(6): 1071-1080, 2018 Nov 01.
Article in English | MEDLINE | ID: mdl-30542601

ABSTRACT

Quantum dots (QDs) are used in the bio-medical area because of their excellent optical properties. Their biomedical utilization has remained a serious biosecurity concern. Cytotoxicity experiments have shown that QD toxicity is connected to the properties of the QDs. In this paper, the toxicity of QDs was studied from the aspect of surface functional groups at the mitochondrial level. Three types of ligands, thioglycollic acid (TGA), mercaptoethylamine (MEA) and l-cysteine (l-Cys), which have similar structures but different functional groups were used to coat CdTe QDs. The effects of the three types of CdTe QDs on mitochondria were then observed. The experimental results showed the three types of CdTe QDs could impair mitochondrial respiration, destroy membrane potential and induce mitochondrial swelling. Interestingly, MEA-CdTe QDs showed similar effects on membrane potential and mitochondrial swelling as did l-Cys-CdTe QDs, while TGA-CdTe QDs showed stronger effects than that of the two other QDs. Moreover, the three types of CdTe QDs showed significantly different effects on mitochondrial membrane fluidity. MEA-CdTe QDs decreased mitochondrial membrane fluidity, l-Cys-CdTe QDs showed no obvious influence on mitochondrial membrane fluidity and TGA-CdTe QDs increased mitochondrial membrane fluidity. The interaction mechanism of CdTe QDs on mitochondrial permeability transition (MPT) pores as well as Cd2+ release by CdTe QDs were checked to determine the reason for their different effects on mitochondria. The results showed that the impact of the three types of CdTe QDs on mitochondria was not only related to the released metal ion, but also to their interaction with MPT pore proteins. This work emphasizes the importance of surface functional groups in the behavior of CdTe QDs at the sub-cellular level.

16.
Plant Mol Biol ; 98(1-2): 19-32, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30117035

ABSTRACT

Key message The OsPLS3 locus was isolated by map-based cloning that encodes a DUF266-containing protein. OsPLS3 regulates the onset of leaf senescence in rice. Glycosyltransferases (GTs) are one of the most important enzyme groups required for the modification of plant secondary metabolites and play a crucial role in plant growth and development, however the biological functions of most GTs remain elusive. We reported here the identification and characterization of a novel Oryza sativa premature leaf senescence mutant (ospls3). Through map-based cloning strategy, we determined that 22-bp deletion in the OsPLS3 gene encoding a domain of unknown function 266 (DUF266)-containing protein, a member of GT14-like, underlies the premature leaf senescence phenotype in the ospls3 mutant. The OsPLS3 mRNA levels progressively declined with the age-dependent leaf senescence in wild-type rice, implying a negative role of OsPLS3 in regulating leaf senescence. Physiological analysis, and histochemical staining and transmission electron microscopy assays indicated that the ospls3 mutant accumulated higher levels of ethylene and reactive oxygen species than its wild type. Furthermore, the ospls3 mutant showed hypersensitivity to exogenous 1-aminocyclopropane-1-carboxylic acid, H2O2 and high level of cytokinins. Our results indicated that the DUF266-containing gene OsPLS3 plays an important role in the onset of leaf senescence, in part through cytokinin and ethylene signaling in rice.


Subject(s)
Base Pairing , Genes, Plant , Oryza/growth & development , Oryza/genetics , Plant Leaves/growth & development , Plant Leaves/genetics , Plant Proteins/genetics , Sequence Deletion/genetics , Base Sequence , Cytokinins/pharmacology , Ethylenes/biosynthesis , Gene Expression Regulation, Plant/drug effects , Hydrogen Peroxide/metabolism , Phenotype , Plant Leaves/drug effects , Plant Proteins/metabolism , Protein Transport/drug effects , Respiratory Burst/drug effects , Subcellular Fractions/drug effects , Subcellular Fractions/metabolism
17.
Toxicol Res (Camb) ; 7(2): 147-155, 2018 Mar 01.
Article in English | MEDLINE | ID: mdl-30090570

ABSTRACT

With spreading applications of fluorescent quantum dots (QDs) in biomedical fields in recent years, there is increasing concern over their toxicity. Among various factors, surface ligands play critical roles. Previous studies usually employed QDs with different kinds of surface ligands, but general principles were difficult to be obtained since it was hard to compare these surface ligands with varied chemical structures without common features. Herein, the physicochemical properties of two types of CdTe QDs were kept very similar, but different in the surface ligands with mercaptoacetic acid (TGA) and 3-mercaptopropionic acid (MPA), respectively. These two types of homologous ligands only had a difference in one methylene group (-CH2-). The interactions of the two types of CdTe QDs with bovine serum albumin (BSA), which was one of the main components of cell culture, were studied by fluorescence, UV-vis absorption, and circular dichroism spectroscopy. It was found that the fluorescence quenching of BSA by CdTe QDs followed a static quenching mechanism, and there was no obvious difference in the Stern-Volmer quenching constants and binding constants. The thermodynamic parameters of the two types of QDs were similar. BSA underwent conformational changes upon association with these QDs. By comparing the cytotoxicity of these two types of QDs, TGA-capped QDs were found to be less cytotoxic than MPA-capped QDs. Besides, in the presence of serum proteins, the cytotoxicity of the QDs was reduced. QDs in the absence of serum proteins had a higher internalization efficiency, compared with those in the medium with serum. To the best of our knowledge, this is a rare study focusing on surface ligands with such small variations at the biomolecular and cellular levels. These findings can provide new insights for the design and applications of QDs in complex biological media.

18.
J Exp Bot ; 69(16): 4127-4139, 2018 07 18.
Article in English | MEDLINE | ID: mdl-29868714

ABSTRACT

Cold acclimation-induced cold tolerance is associated with the generation of reactive oxygen species (ROS), nitric oxide (NO), and mitogen-activated protein kinases (MPKs) in plants. Here, we hypothesized that calcium-dependent protein kinases (CPKs) induce a crosstalk among ROS, NO, and MPKs, leading to the activation of abscisic acid (ABA) signaling in plant adaptation to cold stress. Results showed that cold acclimation significantly increased the transcript levels of CPK27 along with the biosynthesis of ABA in tomato (Solanum lycopersicum). Silencing of CPK27 compromised acclimation-induced cold tolerance, generation of hydrogen peroxide (H2O2) in the apoplast, NO and ABA accumulation, and the activation of MPK1/2. Crosstalk among H2O2, NO, and MPK1/2 contributes to the homeostasis of H2O2 and NO, activation of MPK1/2, and cold tolerance. ABA is also critical for CPK27-induced cold tolerance, generation of H2O2 and NO, and the activation of MPK1/2. These results strongly suggest that CPK27 may function as a positive regulator of ABA generation by activating the production of ROS and NO as well as MPK1/2 in cold adaptation.


Subject(s)
Abscisic Acid/metabolism , Acclimatization/physiology , Cold Temperature , Hydrogen Peroxide/metabolism , Nitric Oxide/metabolism , Protein Kinases/metabolism , Solanum lycopersicum/physiology
19.
Open Life Sci ; 13: 250-252, 2018 Jan.
Article in English | MEDLINE | ID: mdl-33817090

ABSTRACT

Chlamydiosis is an important zoonosis which can transmit from birds to humans, and investigation first reported the seroprevalence of Chlamydia psittaci in black-headed gulls (Larus ridibundus) at the Dianchi Lake, China. A total of 1029 serum samples collected from black-headed gulls between 2012-2015 were analyzed. The gulls were randomly caught and blood collected at Dianchi Lake, China. All the samples were analyzed for the presence of antibodies to C. psittaci by indirect hemagglutination assay (IHA). In this survey, the total infection rate was 11.86% (122/1029). The results of the present survey documented the existence of relatively high C. psittaci seroprevalence in black-headed gulls, which have a potential risk to the wild bird health and human health. Comprehensive practical control approaches and measures should be executed.

20.
Plant Physiol ; 176(2): 1311-1326, 2018 02.
Article in English | MEDLINE | ID: mdl-29146776

ABSTRACT

Photoreceptor-mediated light signaling plays a critical role in plant growth, development, and stress responses but its contribution to the spatial regulation of photoinhibition and photoprotection within the canopy remains unclear. Here, we show that low-red/far-red (L-R/FR) ratio light conditions significantly alleviate PSII and PSI photoinhibition in the shade leaves of tomato (Solanum lycopersicum) plants. This protection is accompanied by a phytochrome A-dependent induction of LONG HYPOCOTYL5 (HY5). HY5 binds to the promoter of ABA INSENSITIVE5 (ABI5), triggering RESPIRATORY BURST OXIDASE HOMOLOG1 (RBOH1)-dependent H2O2 production in the apoplast. Decreased levels of HY5, ABI5, and RBOH1 transcripts increased cold-induced photoinhibition and abolished L-R/FR-induced alleviation of photoinhibition. L-R/FR illumination induced nonphotochemical quenching (NPQ) of chlorophyll a fluorescence and increased the activities of Foyer-Halliwell-Asada cycle enzymes and cyclic electron flux (CEF) around PSI. In contrast, decreased HY5, ABI5, and RBOH1 transcript levels abolished the positive effect of L-R/FR on photoprotection. Loss of PROTON GRADIENT REGULATION5-dependent CEF led to increased photoinhibition and attenuated L-R/FR-dependent NPQ. These data demonstrate that HY5 is an important hub in the cross talk between light and cold response pathways, integrating ABA and reactive oxygen species signaling, leading to the attenuation of photoinhibition by enhanced induction of photoprotection in shade leaves.


Subject(s)
Light Signal Transduction/physiology , Plant Leaves/physiology , Plant Proteins/metabolism , Solanum lycopersicum/physiology , Abscisic Acid/metabolism , Gene Expression Regulation, Plant , Hydrogen Peroxide/metabolism , Light , Photosystem I Protein Complex/genetics , Photosystem I Protein Complex/metabolism , Phytochrome A/metabolism , Plant Proteins/genetics , Plants, Genetically Modified , Reactive Oxygen Species/metabolism
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