RESUMO
Callus formation is important for numerous biological processes in plants. Previously, we revealed that the PdeWRKY75-PdeRBOHB module positively regulates hydrogen peroxide (H2 O2 ) accumulation, thereby affecting callus formation in poplar. In this study, we identified and confirmed a transcription factor, PdeERF114, that interacts with PdeWRKY75 both in vitro and in vivo. Gene expression analysis identified both PdeRBOHB and PdeEXPB2 as downstream genes of PdeERF114 and PdeWRKY75. Overexpression (OE) and reduced-expression (RE) transgenic poplar lines for these four genes were generated, and the observation of callus formation was also performed in all plant materials. We demonstrated that PdeERF114 and PdeWRKY75 formed a protein complex and that this complex could bind W-Box motifs in the promoters of PdeRBOHB and PdeEXPB2, thereby positively regulating the expression of PdeRBOHB and PdeEXPB2. The OE/RE transgenic lines for these four genes also showed enhanced/reduced callus formation. Overall, we revealed a novel gene regulatory network for the regulation of callus formation in plants that involves four genes and regulates callus formation through two pathways: the accumulation of H2 O2 in explants and the relaxation of cell walls. In the future, the four genes could be used to enhance transformation effectiveness in genetic engineering.
Assuntos
Populus , Fatores de Transcrição , Regiões Promotoras Genéticas/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Perfilação da Expressão Gênica , Parede Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Populus/genética , Populus/metabolismo , Plantas Geneticamente Modificadas/metabolismoRESUMO
Phosphorus (P) is an important nutrient for plants. Here, we identify a WRKY transcription factor (TF) in poplar (Populus deltoides × Populus euramericana) (PdeWRKY65) that modulates tissue phosphate (Pi) concentrations in poplar. PdeWRKY65 overexpression (OE) transgenic lines showed reduced shoot Pi concentrations under both low and normal Pi availabilities, while PdeWRKY65 reduced expression (RE) lines showed the opposite phenotype. A gene encoding a Pi transporter (PHT), PdePHT1;9, was identified as the direct downstream target of PdeWRKY65 by RNA sequencing (RNA-Seq). The negative regulation of PdePHT1;9 expression by PdeWRKY65 was confirmed by DNA-protein interaction assays, including yeast one-hybrid (Y1H), electrophoretic mobility shift assay (EMSA), co-expression of the promoters of PdePHT1;9 and PdeWRKY65 in tobacco (Nicotiana benthamiana) leaves, and chromatin immunoprecipitation-quantitative PCR. A second WRKY TF, PdeWRKY6, was subsequently identified and confirmed to positively regulate the expression of PdePHT1;9 by DNA-protein interaction assays. PdePHT1;9 and PdeWRKY6 OE and RE poplar transgenic lines were used to confirm their positive regulation of shoot Pi concentrations, under both normal and low Pi availabilities. No interaction between PdeWRKY6 and PdeWRKY65 was observed at the DNA or protein levels. Collectively, these data suggest that the low Pi-responsive TFs PdeWRKY6 and PdeWRKY65 independently regulate the expression of PHT1;9 to modulate tissue Pi concentrations in poplar.
Assuntos
Populus , Fatores de Transcrição , Regulação da Expressão Gênica de Plantas/genética , Fosfatos/metabolismo , Fósforo/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Populus/genética , Populus/metabolismo , Nicotiana/genética , Nicotiana/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Hydrogen peroxide (H2O2) plays important roles in plant development. Adventitious roots (AR), lateral buds (LB) and callus formation are important traits for plants. Here, a gene encoding RESPIRATORY BURST OXIDASE HOMOLOG B (PdeRBOHB) from poplar line 'NL895' (Populus. deltoides × P. euramericana) was predicted to be involved in H2O2 accumulation, and lines with reduced expression were generated. H2O2 content was decreased, and the development of adventitious roots, lateral buds, and callus was inhibited in reduced expression PdeRBOHB lines. A gene encoding PdeWRKY75 was identified as the upstream transcription factor positively regulating PdeRBOHB. This regulation was confirmed by dual luciferase reporter assay, GUS transient expression analysis and electrophoretic mobility shift assay. In the reduced expression PdeWRKY75 lines, H2O2 content was decreased and the development of adventitious roots, lateral buds, and callus development was inhibited, while in the overexpression lines, H2O2 content was increased and the development of adventitious roots and lateral buds was inhibited, but callus formation was enhanced. Additionally, reduced expression PdeRBOHB lines showed lowered expression of PdeWRKY75, while exogenous application of H2O2 showed the opposite effect. Together, these results suggest that PdeWRKY75 and PdeRBOHB are part of a regulatory module in H2O2 accumulation, which is involved in the regulation of multiple biological processes.
Assuntos
Populus , Regulação da Expressão Gênica de Plantas , Peróxido de Hidrogênio/metabolismo , Raízes de Plantas/metabolismo , Populus/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
BACKGROUND: Prior research has demonstrated that the brains of adolescents with depression exhibit distinct structural alterations. However, preliminary studies have documented the pathophysiological changes in certain brain regions, such as the cerebellum, highlighting a need for further research to support the current understanding of this disease. AIM: To study brain changes in depressed adolescents. METHODS: This study enrolled 34 adolescents with depression and 34 age-, sex-, and education-level-matched healthy control (HC) individuals. Structural and functional alterations were identified when comparing the brains of these two participant groups through voxel-based morphometry and cerebral blood flow (CBF) analysis, respectively. Associations between identified brain alterations and the severity of depressive symptoms were explored through Pearson correlation analyses. RESULTS: The cerebellum, superior frontal gyrus, cingulate gyrus, pallidum, middle frontal gyrus, angular gyrus, thalamus, precentral gyrus, inferior temporal gyrus, superior temporal gyrus, inferior frontal gyrus, and supplementary motor areas of adolescents with depression showed an increase in brain volume compared to HC individuals. These patients with depression further presented with a pronounced drop in CBF in the left pallidum (group = 98, and peak t = - 4.4324), together with increased CBF in the right percental gyrus (PerCG) (group = 90, and peak t = 4.5382). In addition, 17-item Hamilton Depression Rating Scale scores were significantly correlated with the increased volume in the opercular portion of the left inferior frontal gyrus (r = - 0.5231, P < 0.01). CONCLUSION: The right PerCG showed structural and CBF changes, indicating that research on this part of the brain could offer insight into the pathophysiological causes of impaired cognition.
RESUMO
Despite the development of sterilization, the study of reactive oxygen species (ROS) based disinfection mechanism is still under restrictions due to the lack of direct evidence. In this work, DiI is used to explore the sterilization mechanism in-depth. The mechanism is directly proven to be that the generated ROS would seriously damage the lipid of the cell membrane. It provides direct evidence for the destruction of cell membrane for the first time. These ROS can cause the death of more than 99% of both Gram-negative and Gram-positive bacteria within 120 min under visible light. What's more, MoS2/MSy (MSy = MnS, CuS, and CeS2) are successfully synthesized by employing Mo/M-MOF (M = Mn, Cu, and Ce) as precursors. Since bigger Fermi lever difference and smaller work function bring better photocatalytic activity, MoS2/MnS composites display superb photocatalytic activity than others. Therefore, the as-prepared materials can be widely used in environmental protection, biotechnology, and clinical therapy.
Assuntos
Molibdênio , Sulfetos , Catálise , Desinfecção , Luz , Espécies Reativas de Oxigênio , Sulfetos/químicaRESUMO
The development of effective nanomaterials for killing anaerobic bacteria is essential for human health and economic development. Here, we propose a new bactericidal mechanism where theoretical calculations are in good agreement with experimental results. The "poison arrow-head" of MoS2 nanosheets enables the vigorous extraction of lipids from the cell membrane. Based on density functional calculations, oxidation active species (OAS) are generated due to the strong adsorption energy between S vacancies in MoS2 and chemical substrates (permonosulfate (PMS) and H2O). These OAS can be visualized as numerous moving "nano killers", constantly oxidizing the lipids around MoS2; thereby, re-releasing the surface of the sharp knife. The process of physical extraction collaborated with chemical oxidation not only precisely positions the cell membrane but also allows for continuous sterilization. This work digs into the mechanism of anaerobic bacterial sterilization, which sheds significant light on biological analysis, antibacterial, cancer therapy, and anti microbiologically influenced corrosion.
Assuntos
Molibdênio , Venenos , Anaerobiose , Antibacterianos/química , Bactérias Anaeróbias , Desinfecção , Humanos , Lipídeos , Molibdênio/químicaRESUMO
The Chinese tallow tree (Triadica sebifera) can produce oil with high content of unsaturated fatty acids in seeds and shows attractive leaf color in autumn and winter. Here, the 739 Mb chromosome-scale genome sequence of the Chinese tallow tree was assembled and it reveals the Chinese tallow tree is a tetraploid. Numerous genes related to nutrition assimilation, energy utilization, biosynthesis of secondary metabolites and resistance significantly expanded or are specific to the Chinese tallow tree. These genes would enable the Chinese tallow tree to obtain high adaptability. More genes in fatty acids biosynthesis in its genome, especially for unsaturated fatty acids biosynthesis, and higher expression of these genes in seeds would be attributed to its high content of unsaturated fatty acids. Cyanidin 3-O-glucoside was identified as the major component of anthocyanin in red leaves. All structural genes in anthocyanin biosynthesis show significantly higher expression in red leaves than in green leaves. Transcription factors, seven MYB and one bHLH, were predicted to regulate these anthocyanin biosynthesis genes. Collectively, we provided insight into the polyploidization, high adaptability and biosynthesis of the high content of unsaturated fatty acids in seeds and anthocyanin in leaves for the Chinese tallow tree.