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1.
Plant Physiol ; 191(1): 280-298, 2023 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-36102807

RESUMEN

Plant height and tiller number are two major factors determining plant architecture and yield. However, in rice (Oryza sativa), the regulatory mechanism of plant architecture remains to be elucidated. Here, we reported a recessive rice mutant presenting dwarf and reduced tillering phenotypes (drt1). Map-based cloning revealed that the phenotypes are caused by a single point mutation in DRT1, which encodes the Class I formin protein O. sativa formin homolog 13 (OsFH13), binds with F-actin, and promotes actin polymerization for microfilament organization. DRT1 protein localized on the plasma membrane (PM) and chloroplast (CP) outer envelope. DRT1 interacted with rice phototropin 2 (OsPHOT2), and the interaction was interrupted in drt1. Upon blue light stimulus, PM localized DRT1 and OsPHOT2 were translocated onto the CP membrane. Moreover, deficiency of DRT1 reduced OsPHOT2 internalization and OsPHOT2-mediated CP relocation. Our study suggests that rice formin protein DRT1/OsFH13 is necessary for plant morphology and CP relocation by modulating the actin-associated cytoskeleton network.


Asunto(s)
Actinas , Oryza , Actinas/metabolismo , Oryza/metabolismo , Forminas/genética , Forminas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Cloroplastos/metabolismo , Mutación/genética , Regulación de la Expresión Génica de las Plantas
2.
Macromol Rapid Commun ; : e2400300, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38950172

RESUMEN

Antibacterial materials with high hydrophobicity have drawbacks such as protein adsorption, bacterial contamination, and biofilm formation, which are responsible for some serious adverse health events. Therefore, antibacterial materials with high hydrophilicity are highly desired. In this paper, UV-curable antibacterial materials are prepared from silicone-containing Choline chloride (ChCl) functionalized hyperbranched quaternary ammonium salts (QAS) and tri-hydroxylethyl acrylate phosphate (TAEP). The materials show high hydrophilic performance because their water contact angle is as low as 19.3°. The materials also exhibit quite high antibacterial efficiency against S. aureus over 95.6%, fairly high transmittance over 90%, and good mechanical performance with tensile strength as high as 6.5 MPa. It reveals that it is a feasible strategy to develop antibacterial materials with low hydrophobicity from silicone-modified ChCl-functionalized hyperbranched QAS.

3.
Int J Mol Sci ; 25(14)2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-39062872

RESUMEN

Rice (Oryza sativa L.), a fundamental global staple, nourishes over half of the world's population. The identification of the ddt1 mutant in rice through EMS mutagenesis of the indica cultivar Shuhui527 revealed a dwarf phenotype, characterized by reduced plant height, smaller grain size, and decreased grain weight. Detailed phenotypic analysis and map-based cloning pinpointed the mutation to a single-base transversion in the LOC_Os03g04680 gene, encoding a cytochrome P450 enzyme, which results in a premature termination of the protein. Functional complementation tests confirmed LOC_Os03g04680 as the DDT1 gene responsible for the observed phenotype. We further demonstrated that the ddt1 mutation leads to significant alterations in gibberellic acid (GA) metabolism and signal transduction, evidenced by the differential expression of key GA-related genes such as OsGA20OX2, OsGA20OX3, and SLR1. The mutant also displayed enhanced drought tolerance, as indicated by higher survival rates, reduced water loss, and rapid stomatal closure under drought conditions. This increased drought resistance was linked to the mutant's improved antioxidant capacity, with elevated activities of antioxidant enzymes and higher expression levels of related genes. Our findings suggest that DDT1 plays a crucial role in regulating both plant height and drought stress responses. The potential for using gene editing of DDT1 to mitigate the dwarf phenotype while retaining improved drought resistance offers promising avenues for rice improvement.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Giberelinas , Mutación , Oryza , Proteínas de Plantas , Oryza/genética , Oryza/crecimiento & desarrollo , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Giberelinas/metabolismo , Agua/metabolismo , Fenotipo , Sequías , Sistema Enzimático del Citocromo P-450/genética , Sistema Enzimático del Citocromo P-450/metabolismo
4.
Int Wound J ; 21(3): e14428, 2023 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-37938886

RESUMEN

A meta-analysis was conducted to evaluate the effect of colostomy or ileostomy on post-operative wound complications. The research was tested using Embase, PubMed and Cochrane Library databases. Included were randomized, controlled clinical trials (RCTs). A sensitivity analysis and a meta-analysis were carried out. The results indicated that there were no statistically significant differences in the reduction of wound infection between LC and LI. Out of 268 related studies, 5 publications were chosen and examined for compliance. Literature quality was evaluated throughout the trial. Studies with poor literature were excluded. The data were analysed with RevMan 5.3, and a decision was taken to analyse the data with either a stochastic or a fixed-effects model. There were no significant differences in the incidence of post-operative infection in patients with LC (OR, 0.79; 95% CI, 0.34, 1.81; p = 0.57), and the incidence of post-operative anastomotic fistulae (OR, 0.98; 95% CI, 0.30, 3.15; p = 0.97) was not significantly different from that with LI. These meta-analyses indicate that no significant reduction in the incidence of post-operative infections or anastomotic fistulae was observed by either LC or LI.

5.
Theor Appl Genet ; 135(5): 1751-1766, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35258682

RESUMEN

Phytohormones performed critical roles in regulating plant architecture and thus determine grain yield in rice. However, the roles of brassinosteroids (BRs) compared to other phytohormones in shaping rice architecture are less studied. In this study, we report that BR hypersensitive1 (BHS1) plays a negative role in BR signaling and regulate rice architecture. BHS1 encodes the kinesin-13a protein and regulates grain length. We found that bhs1 was hypersensitive to BR, while BHS1-overexpression was less sensitive to BR compare to WT. BHS1 was down-regulated at RNA and protein level upon exogenous BR treatment, and proteasome inhibitor MG132 delayed the BHS1 degradation, indicating that both the transcriptional and posttranscriptional regulation machineries are involved in BHS1-mediated regulation of plant growth and development. Furthermore, we found that the BR-induced degradation of BHS1 was attenuated in Osbri1 and Osbak1 mutants, but not in Osbzr1 and Oslic mutants. Together, these results suggest that BHS1 is a novel component which is involved in negative regulation of the BR signaling downstream player of BRI1.


Asunto(s)
Brasinoesteroides , Oryza , Brasinoesteroides/farmacología , Grano Comestible/metabolismo , Regulación de la Expresión Génica de las Plantas , Crecimiento y Desarrollo , Cinesinas/genética , Reguladores del Crecimiento de las Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
6.
Planta ; 254(4): 76, 2021 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-34533642

RESUMEN

MAIN CONCLUSION: A new molecular mechanism of tetrahydrofolate deformylase involved in the salt response presumably affects mitochondrial and chloroplast function by regulating energy metabolism and accumulation of reactive oxygen species. High salinity severely restrains plant growth and development, consequently leading to a reduction in grain yield. It is therefore critical to identify the components involved in plant salt resistance. In our previous study, we identified a rice leaf early-senescence mutant hpa1, which encodes a formyl tetrahydrofolate deformylase (Xiong et al. in Sci China Life Sci 64(5):720-738, 2021). Here, we report that HPA1 also plays a role in the salt response. To explore the molecular mechanism of HPA1 in salt resistance, we attempted to identify the differentially expressed proteins between wild type and hpa1 mutant for salinity treatment using an iTRAQ-based comparative protein quantification approach. A total of 4598 proteins were identified, of which 279 were significantly altered, including 177 up- and 102 down-regulated proteins. A functional analysis suggested that the 279 differentially expressed proteins are involved mainly in the regulation of oxidative phosphorylation, phenylpropanoid biosynthesis, photosynthesis, posttranslational modifications, protein turnover and energy metabolism. Moreover, a deficiency in HPA1 impaired chlorophyll metabolism and photosynthesis in chloroplasts and affected the electron flow of the electron transport chain in mitochondria. These changes led to abnormal energy metabolism and accumulation of reactive oxygen species, which may affect the permeability and integrity of cell membranes, leading to cell death. In addition, the results were verified by transcriptional or physiological experiments. Our results provide an insight into a new molecular mechanism of the tetrahydrofolate cycle protein formyl tetrahydrofolate deformylase, which is involved in the salt response, presumably by affecting mitochondrial and chloroplast function regulating energy metabolism and accumulation of reactive oxygen species under salt stress.


Asunto(s)
Oryza , Regulación de la Expresión Génica de las Plantas , Oryza/genética , Oryza/metabolismo , Fotosíntesis , Hojas de la Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteómica , Tetrahidrofolatos
7.
New Phytol ; 232(2): 655-672, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34260064

RESUMEN

Heat stress is a major environmental threat affecting crop growth and productivity. However, the molecular mechanisms associated with plant responses to heat stress are poorly understood. Here, we identified a heat stress-sensitive mutant, hts1, in rice. HTS1 encodes a thylakoid membrane-localized ß-ketoacyl carrier protein reductase (KAR) involved in de novo fatty acid biosynthesis. Phylogenetic and bioinformatic analysis showed that HTS1 probably originated from streptophyte algae and is evolutionarily conserved in land plants. Thermostable HTS1 is predominantly expressed in green tissues and strongly induced by heat stress, but is less responsive to salinity, cold and drought treatments. An amino acid substitution at A254T in HTS1 causes a significant decrease in KAR enzymatic activity and, consequently, impairs fatty acid synthesis and lipid metabolism in the hts1 mutant, especially under heat stress. Compared to the wild-type, the hts1 mutant exhibited heat-induced higher H2 O2 accumulation, a larger Ca2+ influx to mesophyll cells, and more damage to membranes and chloroplasts. Also, disrupted heat stress signaling in the hts1 mutant depresses the transcriptional activation of HsfA2s and the downstream target genes. We suggest that HTS1 is critical for underpinning membrane stability, chloroplast integrity and stress signaling for heat tolerance in rice.


Asunto(s)
Oryza , Termotolerancia , Proteínas Portadoras , Sequías , Ácidos Grasos , Regulación de la Expresión Génica de las Plantas , Oryza/genética , Oryza/metabolismo , Oxidorreductasas , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/metabolismo , Estrés Fisiológico/genética
8.
Photosynth Res ; 137(1): 53-67, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29392476

RESUMEN

Isolation of leaf-color mutants is important in understanding the mechanisms of chloroplast biogenesis and development. In this study, we identified and characterized a rice (Oryza sativa) mutant, yellow leaf 2 (yl2), exhibiting pale yellow leaves with a few longitudinal white stripes at the early seedling stage then gradually turning yellow. Genetic analyses revealed that YL2 encodes a thylakoid membrane-localized protein with significant sequence similarity to UMP kinase proteins in prokaryotes and eukaryotes. Prokaryotic UMP kinase activity was subsequently confirmed, with YL2 deficiency causing a significant reduction in chlorophyll accumulation and photochemical efficiency. Moreover, YL2 is also light dependent and preferentially expressed in green tissues. Chloroplast development was abnormal in the yl2 mutant, possibly due to reduced accumulation of thylakoid membranes and a lack of normal stroma lamellae. 2D Blue-Native SDS-PAGE and immunoblot analyses revealed a reduction in several subunits of photosynthetic complexes, in particular, the AtpB subunit of ATP synthase, while mRNA levels of corresponding genes were unchanged or increased compared with the wild type. In addition, we observed a significant decrease (ca. 36.3%) in cpATPase activity in the yl2 mutant compared with the wild type. Taken together, our results suggest that UMP kinase activity plays an essential role in chloroplast development and regulating cpATPase biogenesis in rice.


Asunto(s)
Cloroplastos/metabolismo , Nucleósido-Fosfato Quinasa/metabolismo , Oryza/citología , Proteínas de Plantas/metabolismo , ATPasas de Translocación de Protón de Cloroplastos/metabolismo , Cloroplastos/genética , Clonación Molecular , Regulación de la Expresión Génica de las Plantas , Mutación , Nucleósido-Fosfato Quinasa/genética , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Tilacoides/metabolismo
9.
Nature ; 466(7304): 388-92, 2010 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-20512117

RESUMEN

Nucleosomes compact and regulate access to DNA in the nucleus, and are composed of approximately 147 bases of DNA wrapped around a histone octamer. Here we report a genome-wide nucleosome positioning analysis of Arabidopsis thaliana using massively parallel sequencing of mononucleosomes. By combining this data with profiles of DNA methylation at single base resolution, we identified 10-base periodicities in the DNA methylation status of nucleosome-bound DNA and found that nucleosomal DNA was more highly methylated than flanking DNA. These results indicate that nucleosome positioning influences DNA methylation patterning throughout the genome and that DNA methyltransferases preferentially target nucleosome-bound DNA. We also observed similar trends in human nucleosomal DNA, indicating that the relationships between nucleosomes and DNA methyltransferases are conserved. Finally, as has been observed in animals, nucleosomes were highly enriched on exons, and preferentially positioned at intron-exon and exon-intron boundaries. RNA polymerase II (Pol II) was also enriched on exons relative to introns, consistent with the hypothesis that nucleosome positioning regulates Pol II processivity. DNA methylation is also enriched on exons, consistent with the targeting of DNA methylation to nucleosomes, and suggesting a role for DNA methylation in exon definition.


Asunto(s)
Arabidopsis/genética , Arabidopsis/metabolismo , Ensamble y Desensamble de Cromatina/fisiología , Metilación de ADN/fisiología , Nucleosomas/metabolismo , Arabidopsis/enzimología , Ensamble y Desensamble de Cromatina/genética , Inmunoprecipitación de Cromatina , Metilación de ADN/genética , ADN Polimerasa II/análisis , ADN Polimerasa II/metabolismo , ADN de Plantas/genética , ADN de Plantas/metabolismo , Exones/genética , Genes de Plantas/genética , Genoma de Planta/genética , Humanos , Nucleasa Microcócica/metabolismo , Nucleosomas/genética , Análisis de Secuencia de ADN
10.
J Agric Food Chem ; 72(36): 19629-19643, 2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39207175

RESUMEN

Brassinosteroids (BRs) are crucial plant hormones influencing diverse developmental processes in rice. While several enzymes in BR biosynthesis have been identified, their regulatory mechanisms remain largely unknown. This study highlights a novel regulatory pathway wherein the CHD3 chromatin remodeler, BLA1, epigenetically modulates the expression of key BR biosynthesis genes, BRD1 and D2. Phenotypic analysis of bla1 mutants revealed significant alterations, such as increased leaf angles and longer mesocotyls, which were alleviated by BR synthesis inhibitors. Moreover, the bla1 mutants showed elevated BR levels that correlated with the significant upregulation of the expression levels of BRD1 and D2, particularly at the lamina joint sites. Mechanistically, the yeast one-hybrid and chromatin immunoprecipitation assays revealed specific binding of BLA1 to the promoter regions of BRD1 and D2, accompanied by a marked enrichment of the transcriptionally active histone modification, H3K4me3, on these loci in the bla1 mutant. Functional assessments of the brd1 and d2 mutants confirmed their reduced sensitivity to BR, further underscoring their critical regulatory roles in BR-mediated developmental processes. Our findings uncovered an epigenetic mechanism that governs BR biosynthesis and orchestrates the expression of BRD1 and D2 to modulate BR levels and influence rice growth and development.


Asunto(s)
Brasinoesteroides , Regulación de la Expresión Génica de las Plantas , Oryza , Hojas de la Planta , Proteínas de Plantas , Oryza/genética , Oryza/metabolismo , Oryza/crecimiento & desarrollo , Brasinoesteroides/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Hojas de la Planta/metabolismo , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , Epigénesis Genética , Reguladores del Crecimiento de las Plantas/metabolismo , Mutación
11.
Rice (N Y) ; 17(1): 51, 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39136883

RESUMEN

BACKGROUND: The identification of spotted leaf 50 (spl50), a novel lesion mimic mutant (LMM) in rice, provides critical insights into the mechanisms underlying programmed cell death (PCD) and innate immunity in plants. RESULTS: Based on ethyl methane sulfonate (EMS)-induced mutagenesis, the spl50 mutant mimics hypersensitive responses in the absence of pathogen by displaying spontaneous necrotic lesions after the tillering phase. SPL50, an ARM repeat protein essential for controlling reactive oxygen species (ROS) metabolism and boosting resistance to blast disease, was identified by map-based cloning techniques. This work also demonstrates the detrimental effects of spl50 on photosynthetic efficiency and chloroplast development. The crucial significance of SPL50 in cellular signaling and stress response is shown by its localization to the cytoplasm and constitutive expression in various plant tissues. In light of growing concerns regarding global food security, this study highlights the pivotal role of SPL50 in regulating programmed cell death (PCD) and enhancing the immune response in plants, contributing to strategies for improving crop disease resistance. CONCLUSIONS: The novel identification of the SPL50 gene in rice, encoding an ARM repeat protein, reveals its pivotal role in regulating PCD and innate immune responses independently of pathogen attack.

12.
Proc Natl Acad Sci U S A ; 107(43): 18557-62, 2010 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-20937886

RESUMEN

Posttranslational modifications of histones play important roles in modulating chromatin structure and regulating gene expression. We have previously shown that more than two thirds of Arabidopsis genes contain histone H3 methylation at lysine 4 (H3K4me) and that trimethylation of H3K4 (H3K4me3) is preferentially located at actively transcribed genes. In addition, several Arabidopsis mutants with locus-specific loss of H3K4me have been found to display various developmental abnormalities. These findings suggest that H3K4me3 may play important roles in maintaining the normal expression of a large number of genes. However, the major enzyme(s) responsible for H3K4me3 has yet to be identified in plants, making it difficult to address questions regarding the mechanisms and functions of H3K4me3. Here we described the characterization of SET DOMAIN GROUP 2 (SDG2), a large Arabidopsis protein containing a histone lysine methyltransferase domain. We found that SDG2 homologs are highly conserved in plants and that the Arabidopsis SDG2 gene is broadly expressed during development. In addition, the loss of SDG2 leads to severe and pleiotropic phenotypes, as well as the misregulation of a large number of genes. Consistent with our finding that SDG2 is a robust and specific H3K4 methyltransferase in vitro, the loss of SDG2 leads to a drastic decrease in H3K4me3 in vivo. Taken together, these results suggest that SDG2 is the major enzyme responsible for H3K4me3 in Arabidopsis and that SDG2-dependent H3K4m3 is critical for regulating gene expression and plant development.


Asunto(s)
Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , Arabidopsis/genética , Genes de Plantas , N-Metiltransferasa de Histona-Lisina/genética , N-Metiltransferasa de Histona-Lisina/metabolismo , Arabidopsis/crecimiento & desarrollo , Secuencia de Bases , Secuencia Conservada , Cartilla de ADN/genética , Regulación del Desarrollo de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Histonas/química , Histonas/metabolismo , Mutación , Filogenia , Plantas Modificadas Genéticamente
13.
Bio Protoc ; 13(4): e4611, 2023 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-36845530

RESUMEN

Chloroplast movement has been observed and analyzed since the 19th century. Subsequently, the phenomenon is widely observed in various plant species such as fern, moss, Marchantia polymorpha, and Arabidopsis. However, chloroplast movement in rice is less investigated, presumably due to the thick wax layer on its leaf surface, which reduces light sensitivity to the point that it was previously believed that there was no light-induced movement in rice. In this study, we present a convenient protocol suitable for observing chloroplast movement in rice only by optical microscopy without using special equipment. It will allow researchers to explore other signaling components involved in chloroplast movement in rice.

14.
Am J Transl Res ; 14(3): 2117-2122, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35422962

RESUMEN

OBJECTIVE: To investigate the clinical effect of pelvic floor muscle training (PFMT) plus biofeedback electrical stimulation (BES) on stress urinary incontinence (SUI). METHODS: 110 patients with SUI admitted to our hospital in the Department of Obstetrics and Gynecology from November 2018 to November 2019 were selected and divided into control group (n=55) and study group (n=55). The study group received PFMT plus BES while the control group received PFMT alone. RESULTS: Compared with the control group, the incontinence quality of life (I-QOL) score and the international consultation on incontinence questionnaire-urinary incontinence short form (ICI-Q-SF) score in the study group were significantly better (P<0.05), and the patients had better pelvic floor muscle endurance, strength, and coordination (P<0.05). CONCLUSION: PFMT plus BES could improve the strength, endurance, and coordination of pelvic floor muscles in SUI patients. It can positively influence the improvement of the I-QOL and ICI-Q-SF scores. CLINICAL TRIAL REGISTRATION: The name of the registry: Chinese Registry of Clinical Trials. TRIAL REGISTRATION NUMBER: ChiCTR21000684765. Trial URL: http://www.chictr.org.cn/showproj.aspx?proj=73654424.

15.
Clin Nutr ; 41(6): 1425-1433, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35450768

RESUMEN

The Global Leadership Initiative on Malnutrition (GLIM) provides consensus criteria for the diagnosis of malnutrition that can be widely applied. The GLIM approach is based on the assessment of three phenotypic (weight loss, low body mass index, and low skeletal muscle mass) and two etiologic (low food intake and presence of disease with systemic inflammation) criteria, with diagnosis confirmed by any combination of one phenotypic and one etiologic criterion fulfilled. Assessment of muscle mass is less commonly performed than other phenotypic malnutrition criteria, and its interpretation may be less straightforward, particularly in settings that lack access to skilled clinical nutrition practitioners and/or to body composition methodologies. In order to promote the widespread assessment of skeletal muscle mass as an integral part of the GLIM diagnosis of malnutrition, the GLIM consortium appointed a working group to provide consensus-based guidance on assessment of skeletal muscle mass. When such methods and skills are available, quantitative assessment of muscle mass should be measured or estimated using dual-energy x-ray absorptiometry, computerized tomography, or bioelectrical impedance analysis. For settings where these resources are not available, then the use of anthropometric measures and physical examination are also endorsed. Validated ethnic- and sex-specific cutoff values for each measurement and tool are recommended when available. Measurement of skeletal muscle function is not advised as surrogate measurement of muscle mass. However, once malnutrition is diagnosed, skeletal muscle function should be investigated as a relevant component of sarcopenia and for complete nutrition assessment of persons with malnutrition.


Asunto(s)
Desnutrición , Estado Nutricional , Femenino , Humanos , Liderazgo , Masculino , Desnutrición/etiología , Prolapso de la Válvula Mitral , Músculo Esquelético , Miopía , Evaluación Nutricional , Enfermedades de la Piel , Pérdida de Peso
16.
Plant J ; 63(2): 312-328, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20444225

RESUMEN

Kinesins are encoded by a large gene family involved in many basic processes of plant development. However, the number of functionally identified kinesins in rice is very limited. Here, we report the functional characterization of Brittle Culm12 (BC12), a gene encoding a kinesin-4 protein. bc12 mutants display dwarfism resulting from a significant reduction in cell number and brittleness due to an alteration in cellulose microfibril orientation and wall composition. BC12 is expressed mainly in tissues undergoing cell division and secondary wall thickening. In vitro biochemical analyses verified BC12 as an authentic motor protein. This protein was present in both the nucleus and cytoplasm and associated with microtubule arrays during cell division. Mitotic microtubule array comparison, flow cytometric analysis and expression assays of cyclin-dependent kinase (CDK) complexes in root-tip cells showed that cell-cycle progression is affected in bc12 mutants. BC12 is very probably regulated by CDKA;3 based on yeast two-hybrid and microarray data. Therefore, BC12 functions as a dual-targeting kinesin protein and is implicated in cell-cycle progression, cellulose microfibril deposition and wall composition in the monocot plant rice.


Asunto(s)
Ciclo Celular , Pared Celular/metabolismo , Cinesinas/metabolismo , Oryza/crecimiento & desarrollo , Proteínas de Plantas/metabolismo , Clonación Molecular , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Microtúbulos/metabolismo , Oryza/genética , Fosforilación , Proteínas de Plantas/genética , ARN de Planta/genética
17.
Plant J ; 64(1): 56-70, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20663087

RESUMEN

Membrane trafficking between the plasma membrane (PM) and intracellular compartments is an important process that regulates the deposition and metabolism of cell wall polysaccharides. Dynamin-related proteins (DRPs), which function in membrane tubulation and vesiculation are closely associated with cell wall biogenesis. However, the molecular mechanisms by which DRPs participate in cell wall formation are poorly understood. Here, we report the functional characterization of Brittle Culm3 (BC3), a gene encoding OsDRP2B. Consistent with the expression of BC3 in mechanical tissues, the bc3 mutation reduces mechanical strength, which results from decreased cellulose content and altered secondary wall structure. OsDRP2B, one of three members of the DRP2 subfamily in rice (Oryza sativa L.), was identified as an authentic membrane-associated dynamin via in vitro biochemical analyses. Subcellular localization of fluorescence-tagged OsDRP2B and several compartment markers in protoplast cells showed that this protein not only lies at the PM and the clathrin-mediated vesicles, but also is targeted to the trans-Golgi network (TGN). An FM4-64 uptake assay in transgenic plants that express green fluorescent protein-tagged OsDRP2B verified its involvement in an endocytic pathway. BC3 mutation and overexpression altered the abundance of cellulose synthase catalytic subunit 4 (OsCESA4) in the PM and in the endomembrane systems. All of these findings lead us to conclude that OsDRP2B participates in the endocytic pathway, probably as well as in post-Golgi membrane trafficking. Mutation of OsDRP2B disturbs the membrane trafficking that is essential for normal cellulose biosynthesis of the secondary cell wall, thereby leading to inferior mechanical properties in rice plants.


Asunto(s)
Pared Celular/metabolismo , Celulosa/biosíntesis , Dinaminas/metabolismo , Oryza/genética , Proteínas de Plantas/metabolismo , Clonación Molecular , Biología Computacional , Dinaminas/genética , Endocitosis , Regulación de la Expresión Génica de las Plantas , Mutación , Oryza/enzimología , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente/enzimología , Plantas Modificadas Genéticamente/genética , ARN de Planta/genética
18.
Sci China Life Sci ; 64(5): 720-738, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-32949368

RESUMEN

It is well established that an abnormal tetrahydrofolate (THF) cycle causes the accumulation of hydrogen peroxide (H2O2) and leaf senescence, however, the molecular mechanism underlying this relationship remains largely unknown. Here, we reported a novel rice tetrahydrofolate cycle mutant, which exhibited H2O2 accumulation and early leaf senescence phenotypes. Map-based cloning revealed that HPA1 encodes a tetrahydrofolate deformylase, and its deficiency led to the accumulation of tetrahydrofolate, 5-formyl tetrahydrofolate and 10-formyl tetrahydrofolate, in contrast, a decrease in 5,10-methenyl-tetrahydrofolate. The expression of tetrahydrofolate cycle-associated genes encoding serine hydroxymethyl transferase, glycine decarboxylase and 5-formyl tetrahydrofolate cycloligase was significantly down-regulated. In addition, the accumulation of H2O2 in hpa1 was not caused by elevated glycolate oxidation. Proteomics and enzyme activity analyses further revealed that mitochondria oxidative phosphorylation complex I and complex V were differentially expressed in hpa1, which was consistent with the H2O2 accumulation in hpa1. In a further feeding assay with exogenous glutathione (GSH), a non-enzymatic antioxidant that consumes H2O2, the H2O2 accumulation and leaf senescence phenotypes of hpa1 were obviously compensated. Taken together, our findings suggest that the accumulation of H2O2 in hpa1 may be mediated by an altered folate status and redox homeostasis, subsequently triggering leaf senescence.


Asunto(s)
Ácido Fólico/metabolismo , Formiato-Tetrahidrofolato Ligasa/metabolismo , Homeostasis , Peróxido de Hidrógeno/metabolismo , Oryza , Hojas de la Planta/metabolismo , Senescencia de la Planta , Antioxidantes , Genes de Plantas , Glutatión , Mutación , Oxidación-Reducción
19.
Shanghai Kou Qiang Yi Xue ; 29(5): 504-508, 2020 Oct.
Artículo en Zh | MEDLINE | ID: mdl-33543217

RESUMEN

PURPOSE: To evaluate the accuracy of 6D computed-derived implant guides made in China, in order to provide methods and basis for reducing deviation. METHODS: 3D rapid prototyping technique was used to fabricate implant guides for auxiliary surgical implantation in edentulous patients, and the position deviation between the preoperative design and the actual implant was measured. Sixteen edentulous patients with 172 implantation sites were measured. In 10 patients, six implants were implanted in the maxilla, 4 implants in the mandible, and 6 implants were implanted both in the maxilla and mandible of 6 patients. A total of 28 implants were tilted implant in 14 patients. Preoperative cone-beam CT(CBCT) data were imported into the 6D Dental Planning Software to design and make the implant guides. Digital guides were used to assist implant placement. Preoperative design and postoperative CBCT were imported into the software for 3D reconstruction and registration, and then exported to Geomagic Studio software for analysis to obtain the deviation between the preoperative design and the implantation, so as to analyze the accuracy of the guides. The differences were analyzed by SPSS 25.0 software package with paired t-test and single factor analysis of variance. RESULTS: The distance deviation of implant neck center point was (0.83±0.27) mm and the horizontal deviation was (0.60±0.21) mm. The distance deviation of implant bottom center point was (1.11±0.35) mm, and the vertical deviation was (0.45±0.19) mm. The angle deviation was (3.16±1.73)°. CONCLUSIONS: The 6D computed-derived implant guides made in China can improve the accuracy and efficiency of implant surgery for edentulous patients and obtain a better long-term clinical effect to meet clinical requirements well. Since the deviation is similar to other implant guide plate systems that reported aborad, it must be taken into account in the process of clinical design, in order to avoid risks and unnecessary complications. This method is worthy of wide clinical application.


Asunto(s)
Implantes Dentales , Boca Edéntula , Cirugía Asistida por Computador , China , Diseño Asistido por Computadora , Tomografía Computarizada de Haz Cónico , Implantación Dental Endoósea , Humanos , Imagenología Tridimensional , Boca Edéntula/diagnóstico por imagen , Boca Edéntula/cirugía
20.
Dalton Trans ; 47(4): 1171-1178, 2018 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-29292428

RESUMEN

Photocatalytic hydrogen production from water using a noble-metal-free catalyst has aroused tremendous and interdisciplinary attention. In this work, we report a series of original noble-metal-free ternary nanocomposites of C3N4-Zn0.5Cd0.5S heterojunctions loaded with NiS by a precipitation hydrothermal method. They were characterized by XRD, TEM, SEM-EDS, UV-vis, XPS, PL spectra, and transient photocurrent response measurements. The facts proved that they were efficient and stable photocatalysts to enhance the hydrogen production activity prepared by the precipitation hydrothermal method. Among these photocatalysts, C3N4-Zn0.5Cd0.5S-1% NiS showed excellent photocatalytic performance with a H2-production rate of 53.190 mmol g-1 h-1 which is 405 times higher than the pure CN. The high catalytic activity was attributed to the synergistic effect of the NiS cocatalyst and the nanoheterojunctions between ZCS nanoparticles and 2D CN nanosheets, which were propitious to accelerate charge transfer, promote the separation of photogenerated electron-hole pairs and expedite the surface H2-evolution kinetics.

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