Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Food Chem ; 305: 125440, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31494496

RESUMO

Tea (Camellia sinensis) contains two active glutamate decarboxylases (CsGADs), whose unclear properties were examined here. CsGAD1 was 4-fold higher than CsGAD2 in activity. Their Km values for L-glutamate were around 5 mM. CsGAD1 and CsGAD2 performed best at 55 and 40 °C, respectively, and were both stimulated by calcium/calmodulin (Ca2+/CaM). Over 40 °C, their calmodulin-binding domains degraded. CsGADs were most active at pH 5.6, and were stimulated by Ca2+/CaM at pH 5.6-6.6, but inactivated at pH 3.6. Ca2+/CaM restored the CsGAD1 activity suppressed by inhibitors. CsGADs and CsCaM were localized to the cytosol. CsGAD1 was more highly expressed in most tissues, while CsGAD2 expression was more induced under stresses. The characteristics we first elucidated here revealed that CsGAD1 is the predominant isoform in tea plant, with CsGAD2 exhibiting a supplementary role under certain conditions. The information will contribute to regulation of GABA tea quality.

3.
PLoS One ; 14(9): e0221076, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31509542

RESUMO

BACKGROUND: Obesity is highly prevalent worldwide. More and more studies have been conducted on the relationship between H. pylori infection and obesity or overweight. But the relationship between them is controversial in the literatures and there is no comprehensive evidence for the correlation. AIM: To evaluate the prevalence of H. pylori infection in Chinese adult subjects who received routine physical examinations and the relationship between H. pylori and obesity. METHODS: Literatures on H. pylori infection and obesity in Chinese population were searched in online databases. Relevant data were extracted independently by two researchers and meta-analysis was performed by using Review manager 5.3 software. RESULTS: 22 articles were selected with a total sample size of 178033. The pooled prevalence of H. pylori was 42% (95%CI: 37% to 47%) and mean difference of BMI between subjects with and without H. pylori infection was 0.94 (95%CI: -0.04 to 1.91). 9 eligible studies with 27111 subjects were used to calculated pooled OR value because they contained obesity groups. The OR value showed that H. pylori-positive subjects tended to be obese at a risk of 1.20 (95% CI: 1.13 to 1.28). CONCLUSION: In China, obesity has association with H. pylori infection. H. pylori infection may be one of the risk factors for obesity.

4.
J Exp Bot ; 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31559427

RESUMO

LAZY 1 family genes play important roles in both shoot and root gravitropism in plants. Here we report a Lotus japonicus mutant that displays negative gravitropic response in primary and lateral roots. Map-based cloning identified the mutant gene LjLAZY3 as a functional ortholog of the LAZY1 gene. The mutation of the LjLAZY3 gene reduced rootward polar auxin transport (PAT) in the primary root, which was also insensitive to the PAT inhibitor N-1-naphthylphthalamic acid. Moreover, immunolocalization of eGFP-tagged LjLAZY3 in L. japonicus exhibited the polar localization of LjLAZY3 on the plasma membrane in root stele cells. We therefore suggest that the polar localization of LjLAZY3 in stele cells might be required for PAT in L. japonicus root. LjLAZY3 transcripts displayed asymmetric distribution at the root tip within hours of gravistimulation, while overexpression of LjLAZY3 under a constitutive promoter in Ljlazy3 rescued the gravitropic response in roots. These data indicate that root gravitropism depends on the presence of LjLAZY3 but not its asymmetric expression in root tips. Expression of other LAZY genes in Ljlazy3 background did not rescue the growth direction of roots, suggesting that the LjLAZY3 gene plays a distinct role in root gravitropism in L.japonicus.

5.
J Agric Food Chem ; 67(23): 6541-6550, 2019 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-31125230

RESUMO

The enzymatic hydrolysis of glycosidically bound volatiles (GBVs) plays an important role in tea aroma formation during the tea manufacturing process. However, during the enzyme-active manufacturing process of oolong tea, most GBVs showed no reduction, while ( Z)-3-hexenyl-ß-glucopyranoside significantly enhanced at the turnover stage. This study aimed to determine the reason for this increase in ( Z)-3-hexenyl-ß-glucopyranoside. Continuous wounding stress in the turnover stage did not enhance the expression level of glycosyltransferase 1 ( CsGT1), while it induced a significant increase in the ( Z)-3-hexenol content ( p ≤ 0.05). Furthermore, observing the cell structures of tea leaves exposed to continuous wounding and subcellular localizations of CsGTs suggested that the interaction of ( Z)-3-hexenol (substrate) and CsGT1 (enzyme) was available. In conclusion, both continuous wounding and subcellular localizations led to a ( Z)-3-hexenyl-ß-glucopyranoside enhancement mechanism during the oolong tea's turnover stage. These results advance our understanding of GBV formation during the tea manufacturing process and their relationship with the stress from the tea manufacturing process. In addition, the information will help us further evaluate contribution of GBVs to enzymatic formation of oolong tea aroma compounds.


Assuntos
Camellia sinensis/química , Manipulação de Alimentos/métodos , Glucosídeos/análise , Camellia sinensis/enzimologia , Camellia sinensis/genética , Camellia sinensis/fisiologia , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Folhas de Planta/química , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico , Compostos Orgânicos Voláteis/análise
6.
Food Chem ; 270: 17-24, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30174031

RESUMO

Aromatic aroma compounds contribute to flavor of tea (Camellia sinensis (L.) O. Kuntze) and they are mostly derived from l-phenylalanine via trans-cinnamic acid or directly from l-phenylalanine. The objective of this study was to investigate whether an alternative pathway derived from l-phenylalanine via phenylpyruvic acid is involved in formation of aroma compounds in tea. Enzyme reaction with phenylpyruvic acid showed that benzaldehyde, benzyl alcohol, and methyl benzoate were derived from phenylpyruvic acid in tea leaves. Feeding experiments using [2H8]l-phenylalanine indicated that phenylpyruvic acid was derived from l-phenylalanine in a reaction catalyzed by aromatic amino acid aminotransferases (AAATs). CsAAAT1 showed higher catalytic efficiency towards l-phenylalanine (p ≤ 0.001) while CsAAAT2 showed higher catalytic efficiency towards l-tyrosine (p ≤ 0.001). Both CsAAATs were localized in the cytoplasm of leaf cells. In conclusion, an alternative pathway for the formation of aromatic aroma compounds derived from l-phenylalanine via phenylpyruvic acid occurred in tea leaves.


Assuntos
Fenilalanina/análise , Ácidos Fenilpirúvicos/análise , Folhas de Planta/química , Chá/química , Camellia sinensis/química
7.
Food Chem ; 276: 93-100, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30409668

RESUMO

l-Theanine is a specialized metabolite in tea (Camellia sinensis) leaves that contributes to tea function and quality. Yellow tea leaves (albino) generally have higher l-theanine contents than green tea leaves (normal), but the reason is unknown. The objective of this study was to investigate why l-theanine is accumulated in yellow tea leaves. We compared original normal leaves (green) and light-sensitive albino leaves (yellow) of cv. Yinghong No. 9. The l-theanine content was significantly higher in yellow leaves than in green leaves (p ≤ 0.01). After supplementation with [2H5]-l-theanine, yellow leaves catabolized less [2H5]-l-theanine than green leaves (p ≤ 0.05). Furthermore, most plants contained the enzyme catalyzing l-theanine conversion to ethylamine and l-glutamic acid. In conclusion, l-theanine accumulation in albino-induced yellow tea leaves was due to weak l-theanine catabolism. The differential accumulation mechanism differed from the l-theanine accumulation mechanism in tea and other plants.


Assuntos
Camellia sinensis/química , Glutamatos/análise , Folhas de Planta/química , Camellia sinensis/metabolismo , Etilaminas/análise , Etilaminas/metabolismo , Glutamatos/metabolismo , Ácido Glutâmico/análise , Ácido Glutâmico/metabolismo , Hidrolases/metabolismo , Folhas de Planta/metabolismo
8.
Int J Mol Sci ; 19(8)2018 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-30126188

RESUMO

Jasmonic acid (JA) is reportedly involved in the interaction between insects and the vegetative parts of horticultural crops; less attention has, however, been paid to its involvement in the interaction between insects and the floral parts of horticultural crops. Previously, we investigated the allene oxide synthase 2 (AOS2) gene that was found to be the only JA synthesis gene upregulated in tea (Camellia sinensis) flowers exposed to insect (Thrips hawaiiensis (Morgan)) attacks. In our present study, transient expression analysis in Nicotiana benthamiana plants confirmed that CsAOS2 functioned in JA synthesis and was located in the chloroplast membrane. In contrast to tea leaves, the metabolite profiles of tea flowers were not significantly affected by 10 h JA (2.5 mM) treatment as determined using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry, and gas chromatography-mass spectrometry. Moreover, JA treatment did not significantly influence ethylene formation in tea flowers. These results suggest that JA in tea flowers may have different functions from JA in tea leaves and other flowers.

9.
PLoS One ; 12(9): e0185269, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28931056

RESUMO

Polyols can serve as a means for the translocation of carbon skeletons and energy between source and sink organs as well as being osmoprotective solutes and antioxidants which may be involved in the resistance of some plants to biotic and abiotic stresses. Polyol/Monosaccharide transporter (PLT) proteins previously identified in plants are involved in the loading of polyols into the phloem and are reported to be located in the plasma membrane. The functions of PLT proteins in leguminous plants are not yet clear. In this study, a total of 14 putative PLT genes (LjPLT1-14) were identified in the genome of Lotus japonicus and divided into 4 clades based on phylogenetic analysis. Different patterns of expression of LjPLT genes in various tissues were validated by qRT-PCR analysis. Four genes (LjPLT3, 4, 11, and 14) from clade II were expressed at much higher levels in nodule than in other tissues. Moreover, three of these genes (LjPLT3, 4, and 14) showed significantly increased expression in roots after inoculation with Mesorhizobium loti. Three genes (LjPLT1, 3, and 9) responded when salinity and/or osmotic stresses were applied to L. japonicus. Transient expression of GFP-LjPLT fusion constructs in Arabidopsis and Nicotiana benthamiana protoplasts indicated that the LjPLT1, LjPLT6 and LjPLT7 proteins are localized to the plasma membrane, but LjPLT2 (clade IV), LjPLT3, 4, 5 (clade II) and LjPLT8 (clade III) proteins possibly reside in the Golgi apparatus. The results suggest that members of the LjPLT gene family may be involved in different biological processes, several of which may potentially play roles in nodulation in this nitrogen-fixing legume.


Assuntos
Regulação da Expressão Gênica de Plantas , Lotus/genética , Proteínas de Transporte de Monossacarídeos/genética , Proteínas de Plantas/genética , Proteínas de Arabidopsis/genética , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Lotus/microbiologia , Mesorhizobium/fisiologia , Proteínas de Transporte de Monossacarídeos/metabolismo , Família Multigênica , Pressão Osmótica , Filogenia , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Reação em Cadeia da Polimerase em Tempo Real , Salinidade , Simbiose
10.
J Hazard Mater ; 329: 299-309, 2017 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-28183019

RESUMO

Soil dehydrogenase plays a role in the biological oxidation of soil organic matter and can be considered a good measure of the change of microbial oxidative activity under environmental pollutions. However, the kinetic characteristic of soil dehydrogenase under heavy metal stresses has not been investigated thoroughly. In this study, we characterized the kinetic characteristic of soil dehydrogenase in 14 soil types, and investigated how kinetic parameters changed under spiked with different concentrations of cadmium (Cd). The results showed that the Km and Vmax values of soil dehydrogenase was among 1.4-7.3mM and 15.9-235.2µMh-1 in uncontaminated soils, respectively. In latosolic red soil and brown soil, the inhibitory kinetic mechanism of Cd to soil dehydrogenase was anticompetitive inhibition with inhibition constants (Ki) of 12 and 4.7mM, respectively; in other soils belonged to linear mixed inhibition, the values of Ki were between 0.7-4.2mM. Soil total organic carbon and Ki were the major factors affecting the toxicity of Cd to dehydrogenase activity. In addition, the velocity constant (k) was more sensitive to Cd contamination compared to Vmax and Km, which was established as an early indicator of gross changes in soil microbial oxidative activity caused by Cd contamination.


Assuntos
Cádmio/toxicidade , Oxirredutases/antagonistas & inibidores , Oxirredutases/metabolismo , Solo/química , Cinética
11.
Sci Rep ; 6: 38742, 2016 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-27929095

RESUMO

The physiological functions of sphingolipids in animals have been intensively studied, while less attention has been paid to their roles in plants. Here, we reveal the involvement of sphingolipid delta8 desaturase (SlSLD) in the chilling resistance of tomato (Solanum lycopersicum cv. Micro-Tom). We used the virus-induced gene silencing (VIGS) approach to knock-down SlSLD expression in tomato leaves, and then evaluated chilling resistance. Changes in leaf cell structure under a chilling treatment were observed by transmission electron microscopy. In control plants, SlSLD was highly expressed in the fruit and leaves in response to a chilling treatment. The degree of chilling damage was greater in SlSLD-silenced plants than in control plants, indicating that SlSLD knock-down significantly reduced the chilling resistance of tomato. Compared with control plants, SlSLD-silenced plants showed higher relative electrolytic leakage and malondialdehyde content, and lower superoxide dismutase and peroxidase activities after a chilling treatment. Chilling severely damaged the chloroplasts in SlSLD-silenced plants, resulting in the disruption of chloroplast membranes, swelling of thylakoids, and reduced granal stacking. Together, these results show that SlSLD is crucial for chilling resistance in tomato.


Assuntos
Lycopersicon esculentum/metabolismo , Oxirredutases/metabolismo , Esfingolipídeos/biossíntese , Cloroplastos/metabolismo , Inativação Gênica , Oxirredutases/genética , Temperatura Ambiente
12.
J Agric Food Chem ; 63(31): 6905-14, 2015 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-26212085

RESUMO

It was generally thought that aroma of oolong tea resulted from hydrolysis of glycosidically bound volatiles (GBVs). In this study, most GBVs showed no reduction during the oolong tea manufacturing process. ß-Glycosidases either at protein or gene level were not activated during the manufacturing process. Subcellular localization of ß-primeverosidase provided evidence that ß-primeverosidase was located in the leaf cell wall. The cell wall remained intact during the enzyme-active manufacturing process. After the leaf cell disruption, GBV content was reduced. These findings reveal that, during the enzyme-active process of oolong tea, nondisruption of the leaf cell walls resulted in impossibility of interaction of GBVs and ß-glycosidases. Indole, jasmine lactone, and trans-nerolidol were characteristic volatiles produced from the manufacturing process. Interestingly, the contents of the three volatiles was reduced after the leaf cell disruption, suggesting that mechanical damage with the cell disruption, which is similar to black tea manufacturing, did not induce accumulation of the three volatiles. In addition, 11 volatiles with flavor dilution factor ≥4(4) were identified as relatively potent odorants in the oolong tea. These results suggest that enzymatic hydrolysis of GBVs was not involved in the formation of volatiles of oolong tea, and some characteristic volatiles with potent odorants were produced from the manufacturing process.


Assuntos
Camellia sinensis/enzimologia , Aromatizantes/metabolismo , Proteínas de Plantas/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Camellia sinensis/química , Camellia sinensis/genética , Camellia sinensis/metabolismo , Manipulação de Alimentos , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Glicosídeos/metabolismo , Hidrólise , Folhas de Planta/química , Folhas de Planta/enzimologia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética
13.
New Phytol ; 208(3): 790-802, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26083975

RESUMO

Phytosterols are membrane components or precursors for brassinosteroid (BR) biosynthesis. As they cannot be transported long distances, their homeostasis is tightly controlled through their biosynthesis and metabolism. However, it is unknown whether microRNAs are involved in their homeostatic regulation. Rice (Oryza sativa) plants transformed with microRNA osa-miR1848 and its target, the obtusifoliol 14α-demethylase gene, OsCYP51G3, were used to investigate the role of osa-miR1848 in the regulation of phytosterol biosynthesis. osa-miR1848 directs OsCYP51G3 mRNA cleavage to regulate phytosterol and BR biosynthesis in rice. The role of OsCYP51G3 as one of the osa-miR1848 targets is supported by the opposite expression patterns of osa-miR1848 and OsCYP51G3 in transgenic rice plants, and by the identification of OsCYP51G3 mRNA cleavage sites. Increased osa-miR1848 and decreased OsCYP51G3 expression reduced phytosterol and BR concentrations, and caused typical phenotypic changes related to phytosterol and BR deficiency, including dwarf plants, erect leaves, semi-sterile pollen grains, and shorter cells. Circadian expression of osa-miR1848 regulated the diurnal abundance of OsCYP51G3 transcript in developing organs, and the response of OsCYP51G3 to salt stress. We propose that osa-miR1848 regulates OsCYP51G3 expression posttranscriptionally, and mediates phytosterol and BR biosynthesis. osa-miR1848 and OsCYP51G3 might have potential applications in rice breeding to modulate leaf angle, and the size and quality of seeds.


Assuntos
Brassinosteroides/biossíntese , MicroRNAs/metabolismo , Oryza/metabolismo , Fitosteróis/biossíntese , Esterol 14-Desmetilase/metabolismo , Ritmo Circadiano , Oryza/genética , Oryza/crescimento & desenvolvimento , Fenótipo , Desenvolvimento Vegetal , Esterol 14-Desmetilase/genética , Estresse Fisiológico
14.
Plant Cell Environ ; 38(12): 2662-73, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26012744

RESUMO

Cuticular wax forms a hydrophobic layer covering aerial plant organs and acting as a protective barrier against biotic and abiotic stresses. Compared with well-known wax biosynthetic pathway, molecular regulation of wax biosynthesis is less known. Here, we show that rice OsWS1, a member of the membrane-bound O-acyl transferase gene family, involved in wax biosynthesis and was regulated by an osa-miR1848. OsWS1-tagged green fluorescent protein localized to the endoplasmic reticulum (ER). Compared with wild-type rice, OsWS1 overexpression plants displayed a 3% increase in total wax, especially a 35% increase in very long-chain fatty acids, denser wax papillae around the stoma, more cuticular wax crystals formed on leaf and stem surfaces, pollen coats were thicker and more seedlings survived after water-deficit treatment. In contrast, OsWS1-RNAi and osa-miR1848 overexpression plants exhibited opposing changes. Gene expression analysis showed that overexpression of osa-miR1848 down-regulated OsWS1 transcripts; furthermore, expression profiles of OsWS1 and osa-miR1848 were inversely correlated in the leaf, panicle and stem, and upon water-deficit treatment. These results suggest that OsWS1 is regulated by osa-miR1848 and participates in cuticular wax formation.


Assuntos
Aciltransferases/genética , Regulação Enzimológica da Expressão Gênica , MicroRNAs/genética , Oryza/enzimologia , Ceras/metabolismo , Aciltransferases/metabolismo , Membrana Celular/enzimologia , Retículo Endoplasmático/enzimologia , Regulação da Expressão Gênica de Plantas , Genes Reporter , Oryza/citologia , Oryza/genética , Oryza/fisiologia , Epiderme Vegetal/citologia , Epiderme Vegetal/enzimologia , Epiderme Vegetal/genética , Epiderme Vegetal/fisiologia , Folhas de Planta/citologia , Folhas de Planta/enzimologia , Folhas de Planta/genética , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Caules de Planta/citologia , Caules de Planta/enzimologia , Caules de Planta/genética , Caules de Planta/fisiologia , Plântula/citologia , Plântula/enzimologia , Plântula/genética , Plântula/fisiologia
15.
Cell Biol Int ; 38(5): 639-46, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24446394

RESUMO

Artesunate (ART), derived from a common traditional Chinese medicine, has beeen used an antimalarial for several years. In this study, the effect and mechanism of ART on anti-human cervical cancer cells was examined. The level of prostaglandin E2 (PGE2 ) and the population of CD4+CD25+Foxp3 regulatory T cells (Treg) in peripheral blood were detected by flow cytometry. In vivo antitumor activity was investigated in mice with cervical cancer by the subcutaneous injection of various concentrations of ART. The concentrations of PGE2 in the supernatants of CaSki cells were measured using an ELISA kit. Cyclooxygenase-2 (COX-2) and Foxp3 expression were determined using quantitative polymerase chain reaction (qPCR) and western blot analysis. The effect of ART on the viability of CaSki and Hela cells was evaluated with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. It was identified that the level of PGE2 and the population of CD4+CD25+Foxp3 Treg cells in the peripheral blood were significantly higher in cervical cancer patients and mice with cervical cancer. ART was capable of inhibiting orthotopic tumor growth, which correlated with a decrease in the level of PGE2 and the percentage of Treg cells in mice with cervical cancer. Furthermore, ART decreased COX-2 expression and the production of PGE2 in CaSki and Hela cells. Notably, the supernatants of CaSki cells treated with ART lowered the expression of Foxp3 in Jurkat T cells, which was capable of being reversed by exogenous PGE2 . Our data revealed that ART may elicit an anti-tumor effect against cervical cancer by inhibition of PGE2 production in CaSki and Hela cells, which resulted in the decrease of Foxp3 expression in T cells. Therefore, ART may be an effective drug for immunotherapy of cervical cancer.


Assuntos
Artemisininas/farmacologia , Dinoprostona/antagonistas & inibidores , Fatores de Transcrição Forkhead/antagonistas & inibidores , Regulação Neoplásica da Expressão Gênica , Tolerância Imunológica/efeitos dos fármacos , Neoplasias do Colo do Útero , Animais , Artesunato , Dinoprostona/biossíntese , Feminino , Fatores de Transcrição Forkhead/biossíntese , Células HeLa , Humanos , Tolerância Imunológica/fisiologia , Células Jurkat , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias do Colo do Útero/metabolismo
16.
Plant Biotechnol J ; 11(4): 446-58, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23231455

RESUMO

The plant PTR/NRT1 (peptide transporter/nitrate transporter 1) gene family comprises di/tripeptide and low-affinity nitrate transporters; some members also recognize other substrates such as carboxylates, phytohormones (auxin and abscisic acid), or defence compounds (glucosinolates). Little is known about the members of this gene family in rice (Oryza sativa L.). Here, we report the influence of altered OsPTR9 expression on nitrogen utilization efficiency, growth, and grain yield. OsPTR9 expression is regulated by exogenous nitrogen and by the day-night cycle. Elevated expression of OsPTR9 in transgenic rice plants resulted in enhanced ammonium uptake, promotion of lateral root formation and increased grain yield. On the other hand, down-regulation of OsPTR9 in a T-DNA insertion line (osptr9) and in OsPTR9-RNAi rice plants had the opposite effect. These results suggest that OsPTR9 might hold potential for improving nitrogen utilization efficiency and grain yield in rice breeding.


Assuntos
Nitrogênio/metabolismo , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Oryza/genética , Proteínas de Plantas/genética
17.
J Plant Physiol ; 169(9): 859-66, 2012 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-22475499

RESUMO

The physiological and anatomical attributes of haustoria tissues in hemi-parasitic Santalum album L. seedlings, growing on the potential host, Kuhnia rosmarnifolia Vent., were investigated before and after attachment to the host. Quantization of endogenous levels of indole-3-acetic acid (IAA), zeatin (Z), zeatin riboside (ZR), GA-like substances (GAs) and abscisic acid (ABA) was performed by HPLC. Histological preparations were used to characterize structural differences between pre- and post-attachment haustoria. The contents of GAs and ABA were higher in attached haustoria, with 3.61 and 3.50µgg(-1) fresh weight, respectively, and three times higher than in non-attached haustoria. Cytokinins, Z, ZR and IAA levels were also high, and their contents in attached haustoria increased 2.04-, 2.17-, and 2.82-fold more, respectively, than in non-attached haustoria. A high auxin-to-cytokinin ratio contributed to haustorial development of S. album. A numerous amount of starch in parenchyma cells around the meristematic region above the haustorial gland and the endophyte tissue of the post-attachment haustoria were reported in a Santalaceae member for the first time. Many lysosomes were present and large-scale digestion of host cells occurred at the interface between the parasite and host. The haustorial penetration in S. album into the host stele was suggested to be a function of mechanical force and enzymatic activity. Analysis of the endogenous hormone levels and the structural characters in S. album haustoria indicated that the haustoria were able to synthesize phytohormones, which appeared to be necessary for cell division and differentiation during haustorial development. These results suggest that endogenous hormones are involved in the haustorial development of S. album and in water and nutrient transport in the host-parasite association.


Assuntos
Interações Hospedeiro-Patógeno/fisiologia , Micorrizas/citologia , Micorrizas/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Raízes de Plantas/microbiologia , Santalum/microbiologia , Plântula/microbiologia , Ácido Abscísico/metabolismo , Asteraceae , Giberelinas/metabolismo , Ácidos Indolacéticos/metabolismo , Isopenteniladenosina/análogos & derivados , Isopenteniladenosina/metabolismo , Zeatina/metabolismo
18.
Rice (N Y) ; 5(1): 12, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27234238

RESUMO

BACKGROUND: Oligopeptide transporters (OPTs) play important roles in the mobilization of organic nitrogenous compounds and usually associate with tissues that show signs of rapid protein hydrolysis, such as germinating seeds and senescing leaves. This study is to investigate rice OPT genes. RESULTS: A total of sixteen OsOPT genes (Os for Oryza sative L.) were identified in the rice genome, which were then classified into six sections that belong to two subfamilies (the PT and YSL subfamily). The major mechanisms for evolutionary expansion of the sixteen genes during the rice genome evolution include segmental and tandem duplication. Calculation of the duplication event dates indicated that the sixteen genes originated from nine original OsOPT genes, and the duplication events could be classified into three evolutionary stages. The first evolutionary stage occurred approximately 50 million years ago (Mya) and involved the evolution of four new genes. The second evolutionary stage was approximately 20 Mya and was marked by the appearance of two new genes, and the third evolutionary stage was approximately 9 Mya when two new genes evolved. Mining of the expression database and RT-PCR analysis indicated that the expression of most duplicated OsOPT genes showed high tissue specificities. Diverse expression patterns for the sixteen genes were evaluated using both semi-quantitative RT-PCR and the MPSS data. Expression levels of some OsOPT genes were regulated by abiotic and biotic stresses suggesting the potential involvement of these gene products in rice stress adaptation. Five OsOPT gene mutants showed abnormal development and growth, the primary analysis of five OsOPT gene mutants suggested that they may be necessary for rice development. CONCLUSIONS: These results suggested that rice-specific OsOPT genes might be potentially useful in improving rice.

19.
Plant Foods Hum Nutr ; 66(2): 169-74, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21523413

RESUMO

The contents of starch and catechins in the fresh leaf of 'Huang Zhi Xiang' Oolong tea trees girdled at the bottom, middle (on the big branches) and top (on the small branches) were determined. The study demonstrated that the starch contents from girdled trees were significantly higher (p<0.05) than that from non-girdled ones. Furthermore, the contents of (-)-epicatechin (EC), (-)-epigallocatechin (EGC), total catechins (TC) and simple catechins (SC) from girdled trees were significantly higher (p<0.05) than those from non-girdled ones. Especially, the contents of (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG) and catechin gallate (CG) from girdled at the middle were also significantly higher (p<0.05) than those from the non-girdled. The starch contents were negatively correlated with the contents of (-)-gallocatechin (GC), EC, SC, TC and EGC, while positively correlated with the contents of EGCG and CG in fresh shoots.


Assuntos
Camellia sinensis/química , Catequina/análise , Folhas de Planta/química , Amido/análise , Catequina/análogos & derivados , Cromatografia Líquida de Alta Pressão , Amido/química
20.
Int J Pharm ; 408(1-2): 157-62, 2011 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-21295124

RESUMO

Revaprazan hydrochloride (RH) is a new reversible proton pump inhibitor. However, due to poor water solubility, oral bioavailability of the drug was relatively low. To investigate the particle size reduction effect of RH on dissolution and absorption, three suspensions that containing different sized particles were prepared by high pressure homogenization and in vitro/in vivo evaluations were carried out. DSC and powder X-ray diffraction were used to study crystalline state of freeze dried powder of RH suspensions and the results showed that particles of RH microsuspension and nanosuspension remained in the same crystalline state as coarse suspension, but had lower lattice energy. In the in vitro dissolution test, both microsuspension and nanosuspension showed increased dissolution rate. In the in vivo evaluation, compared to coarse suspension, RH nanosuspension exhibited significant increase in AUC(0-t), C(max) and decrease in T(max), MRT. Nevertheless, RH microsuspension did not display any significant differences in these pharmacokinetic parameters compared to the coarse suspension. The findings revealed that particle size reduction can influence RH absorption in gastrointestinal tract and nanosuspension can enhance oral bioavailability of RH in rats.


Assuntos
Portadores de Fármacos/química , Nanopartículas/química , Inibidores da Bomba de Prótons/química , Pirimidinonas/química , Tetra-Hidroisoquinolinas/química , Administração Oral , Animais , Disponibilidade Biológica , Varredura Diferencial de Calorimetria , Química Farmacêutica , Cristalização , Relação Dose-Resposta a Droga , Liofilização , Masculino , Microscopia Eletrônica de Varredura , Estrutura Molecular , Tamanho da Partícula , Transição de Fase , Pós , Inibidores da Bomba de Prótons/administração & dosagem , Inibidores da Bomba de Prótons/farmacocinética , Pirimidinonas/administração & dosagem , Pirimidinonas/farmacocinética , Ratos , Ratos Wistar , Solubilidade , Propriedades de Superfície , Tetra-Hidroisoquinolinas/administração & dosagem , Tetra-Hidroisoquinolinas/farmacocinética , Difração de Raios X
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA