Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
J Integr Neurosci ; 23(1): 3, 2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38287840

RESUMEN

BACKGROUND: The impact of the methylenetetrahydrofolate reductase (MTHFR) C677T mutation on the relationship between plasma homocysteine (Hcy) levels and stroke has been extensively studied and documented in previous study. However, it remains unclear whether the MTHFR C677T mutation can affect the response to Hcy lowering treatment in stroke patients with hyperhomocysteinemia (HHcy). Understanding the impact of genetic factors on treatment response can help optimize personalized treatment strategies for stroke patients with HHcy. We aimed to investigate the potential association between the MTHFR C677T gene polymorphisms and the effectiveness of Hcy lowering treatment using vitamin therapy in stroke patients with HHcy. METHODS: The MTHFR C677T genotype polymorphisms were identified using polymerase chain reaction-restriction fragment length polymorphism, and the distribution of three genotypes in the MTHFR C677T gene locus was compared. The treatment effects of Hcy lowering agents were compared among patients with different genotypes. RESULTS: Among the 320 stroke patients enrolled in the study, 258 (80.6%) were diagnosed with HHcy. Of these, 162 patients (Effective Group) responded well to the clinical Hcy lowering treatment, while 96 patients (Invalid Group) failed to achieve sufficient response even after taking combination supplements of folic acid, Vitamin B6, and methylcobalamin for one month. Significant differences were observed in terms of age (p < 0.001), hypertension (p = 0.034), dyslipidemia (p = 0.022), hyperuricemia (p = 0.013) and genotype distribution of MTHFR C677T gene polymorphism (p < 0.001) between the Invalid group and the Effective group. The multivariate regression analysis revealed that the T allele (odd rations [OR], 1.327; 95% confidence interval [CI], 1.114-1.580; p = 0.0015) was independently associated with an insufficient Hcy lowering treatment effect. Additionally, the TT genotype was independently associated with insufficient response in both the codominant model (OR, 1.645; 95% CI, 1.093-2.476; p = 0.017) and the recessive model (TT versus CC + CT; OR, 1.529; 95% CI, 1.145-2.042; p = 0.004). However, no relationship was observed between CT + TT genotypes and poor treatment effect in the dominate model. CONCLUSIONS: Our findings suggested that the TT genotype and T allele of MTHFR C677T polymorphism were independently associated with an insufficient Hcy lowering treatment effect in stroke patients with HHcy.


Asunto(s)
Hiperhomocisteinemia , Accidente Cerebrovascular , Humanos , Hiperhomocisteinemia/tratamiento farmacológico , Hiperhomocisteinemia/genética , Polimorfismo Genético , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/genética , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , Homocisteína/genética , Vitaminas
2.
J Environ Sci (China) ; 139: 34-45, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38105060

RESUMEN

In this study, sediment organic phosphorus (OP) and organic carbon (OC) in Lake Taihu, China, as well as their relationships, were analyzed during the outbreak and decline of algal blooms (ABs) over a five-month field study. The results showed synchronous temporal changes in the sediment OP and OC contents with the development of ABs. In addition, there was a significant positive correlation between the sediment OP and OC (p < 0.01), suggesting simultaneous deposition and consumption during the ABs outbreak. The sediment OP and OC contents decreased significantly at the early and last stages of the ABs outbreak and increased at the peak of the ABs outbreak and during the ABs decline. These temporal variation patterns suggest that the sediment OC and OP contents did not consistently increase during the ABs outbreak, even though algae are an important source of organic matter in sediments. The depletion or enrichment of OC and OP in sediments may also depend on the scale of the ABs outbreak. The obtained results revealed significant differences in the sediment OC and OP contents between the months (p < 0.05). In addition, OP in the sediments was dominated by orthophosphate diester (phospholipids and DNA-P) and orthophosphate monoester during the ABs outbreak and decline, respectively. The active OC contents and proportions in the sediments in the ABs outbreak were significantly lower than those observed in the ABs decline period, demonstrating the significant impacts of the ABs outbreak and decline on the sediment OC and OP in Lake Taihu.


Asunto(s)
Lagos , Contaminantes Químicos del Agua , Fósforo/análisis , Carbono , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente/métodos , Sedimentos Geológicos , Eutrofización , China , Fosfatos
3.
Environ Sci Pollut Res Int ; 30(24): 64971-64981, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37071359

RESUMEN

Non-point source pollution caused by rainfall runoff is an important pollution source for river water. To explore the impact of heavy rain on urban river water environments, this paper studied the changes in carbon, nitrogen, and phosphorus levels, composition, and structure in the river water of Kaifeng, China, during the heavy rain in July 2021. The results showed that the concentrations of different forms of carbon, nitrogen, and phosphorus all increased under the effect of the heavy rain. The increase of phosphorus in the river was the largest, and that of carbon was the smallest. The most significant pollution from carbon, nitrogen, and phosphorus occurred in the HJ River. Colored dissolved organic matter (CDOM) was present in the form of macromolecules after the rain, and the degree of humification was deeper compared with before the rain. But heavy rain did not affect the CDOM composition in urban rivers. The spectral slope (SR) and the absorption coefficient at 240 nm to 420 nm (E2/E4) values showed that the CDOM was dominated by exogenous input after the rain, with endogenous pollution again becoming the main factor one week after the rain.


Asunto(s)
Fósforo , Contaminantes Químicos del Agua , Fósforo/análisis , Monitoreo del Ambiente/métodos , Ríos/química , Nitrógeno/análisis , Carbono , Contaminantes Químicos del Agua/análisis , Calidad del Agua , China , Materia Orgánica Disuelta , Lluvia , Agua
4.
Int J Mol Sci ; 23(22)2022 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-36430747

RESUMEN

Salvia miltiorrhiza has been an economically important medicinal plant. Previously, an S. miltiorrhiza mitochondrial genome (mitogenome) assembled from Illumina short reads, appearing to be a single circular molecule, has been published. Based on the recent reports on the plant mitogenome structure, we suspected that this conformation does not accurately represent the complexity of the S. miltiorrhiza mitogenome. In the current study, we assembled the mitogenome of S. miltiorrhiza using the PacBio and Illumina sequencing technologies. The primary structure of the mitogenome contained two mitochondrial chromosomes (MC1 and MC2), which corresponded to two major conformations, namely, Mac1 and Mac2, respectively. Using two approaches, including (1) long reads mapping and (2) polymerase chain reaction amplification followed by Sanger sequencing, we observed nine repeats that can mediate recombination. We predicted 55 genes, including 33 mitochondrial protein-coding genes (PCGs), 3 rRNA genes, and 19 tRNA genes. Repeat analysis identified 112 microsatellite repeats and 3 long-tandem repeats. Phylogenetic analysis using the 26 shared PCGs resulted in a tree that was congruent with the phylogeny of Lamiales species in the APG IV system. The analysis of mitochondrial plastid DNA (MTPT) identified 16 MTPTs in the mitogenome. Moreover, the analysis of nucleotide substitution rates in Lamiales showed that the genes atp4, ccmB, ccmFc, and mttB might have been positively selected. The results lay the foundation for future studies on the evolution of the Salvia mitogenome and the molecular breeding of S. miltiorrhiza.


Asunto(s)
Genoma Mitocondrial , Lamiales , Salvia miltiorrhiza , Salvia , ADN Mitocondrial/genética , Salvia miltiorrhiza/genética , Filogenia , Repeticiones de Microsatélite/genética , Cromosomas
5.
Environ Pollut ; 296: 118761, 2022 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-34971742

RESUMEN

Algal blooms (ABs) can affect the migration of phosphorus (P) among sediments, interstitial water and overlying water. It is important to analyze the characteristics of P and their interactions in the three media during ABs. A 5-month field study (June to October in 2016) was conducted in Zhushan Bay of Lake Taihu. P fractions, P adsorption characteristics and P diffusion fluxes at the sediment-water interface (SWI) were investigated. During the outbreak period of ABs from June to August, labile P concentrations in the sediment measured by diffusive gradients in thin films (DGT-labile P) and its diffusion fluxes across the SWI increased significantly. The equilibrium P concentration (EPC0) of the sediment was higher than the PO43--P concentration in the overlying water. During the period of decline of ABs from September to October, the concentrations and diffusion fluxes of DGT-labile P sharply decreased. However, the sediment total P (TP), overlying water TP, total dissolved P (TDP) and PO43--P concentrations increased. These results show that the ability of sediment solids to supplement interstitial water labile P was significantly enhanced by the outbreak of ABs. Labile P was then intensively released into the overlying water by interstitial water. Degraded algae became a crucial P source during the period of decline of ABs. P from the degraded algae was re-released to the sediment and overlying water. The observed DGT-labile P and DGT-labile Fe coupling in June, September and October confirmed the Fe redox-driven P release mechanism in sediment during these periods. The decoupling of DGT-labile P and DGT-labile Fe was observed in July and August and was probably caused by algal decomposition, labile organic P degradation and/or sulfate reduction in sediment stimulated by the ABs outbreak.


Asunto(s)
Lagos , Contaminantes Químicos del Agua , China , Brotes de Enfermedades , Monitoreo del Ambiente , Eutrofización , Sedimentos Geológicos , Fósforo/análisis , Contaminantes Químicos del Agua/análisis
6.
BMC Plant Biol ; 21(1): 431, 2021 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-34551721

RESUMEN

BACKGROUND: Alpinia species are widely used as medicinal herbs. To understand the taxonomic classification and plastome evolution of the medicinal Alpinia species and correctly identify medicinal products derived from Alpinia species, we systematically analyzed the plastome sequences from five Alpinia species. Four of the Alpinia species: Alpinia galanga (L.) Willd., Alpinia hainanensis K.Schum., Alpinia officinarum Hance, and Alpinia oxyphylla Miq., are listed in the Chinese pharmacopeia. The other one, Alpinia nigra (Gaertn.) Burtt, is well known for its medicinal values. RESULTS: The four Alpinia species: A. galanga, A. nigra, A. officinarum, and A. oxyphylla, were sequenced using the Next-generation sequencing technology. The plastomes were assembled using Novoplasty and annotated using CPGAVAS2. The sizes of the four plastomes range from 160,590 bp for A. galanga to 164,294 bp for A. nigra, and display a conserved quadripartite structure. Each of the plastomes encodes a total of 111 unique genes, including 79 protein-coding, 28 tRNA, and four rRNA genes. In addition, 293-296 SSRs were detected in the four plastomes, of which the majority are mononucleotides Adenine/Thymine and are found in the noncoding regions. The long repeat analysis shows all types of repeats are contained in the plastomes, of which palindromic repeats occur most frequently. The comparative genomic analyses revealed that the pair of the inverted repeats were less divergent than the single-copy region. Analysis of sequence divergence on protein-coding genes showed that two genes (accD and ycf1) had undergone positive selection. Phylogenetic analysis based on coding sequence of 77 shared plastome genes resolves the molecular phylogeny of 20 species from Zingiberaceae. In particular, molecular phylogeny of four sequenced Alpinia species (A. galanga, A. nigra, A. officinarum, and A. oxyphylla) based on the plastome and nuclear sequences showed congruency. Furthermore, a comparison of the four newly sequenced Alpinia plastomes and one previously reported Alpinia plastomes (accession number: NC_048461) reveals 59 highly divergent intergenic spacer regions. We developed and validated two molecular markers Alpp and Alpr, based on two regions: petN-psbM and psaJ-rpl33, respectively. The discrimination success rate was 100 % in validation experiments. CONCLUSIONS: The results from this study will be invaluable for ensuring the effective and safe uses of Alpinia medicinal products and for the exploration of novel Alpinia species to improve human health.


Asunto(s)
Alpinia/clasificación , Alpinia/genética , ADN de Cloroplastos/genética , Evolución Molecular , Marcadores Genéticos , Genoma del Cloroplasto , Secuenciación Completa del Genoma , Variación Genética , Genotipo , Filogenia , Plantas Medicinales/clasificación , Plantas Medicinales/genética
7.
Biotechnol Lett ; 42(11): 2425-2439, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32683523

RESUMEN

OBJECTIVE: To enhance Pi absorption and utilization efficiency of soybean, a member of PHT1 gene family was isolated and characterized from E. salsugineum, which was a homologous gene of AtPHT1;4 and consequently designated as EsPHT1;4. RESULTS: Quantitative real-time PCR (qRT-PCR) analysis showed that the transcript level of EsPHT1;4 significantly increased both in roots and leaves of E. salsugineum under Pi deficient conditions. Furthermore, EsPHT1;4 was transferred to soybean cultivar "YD22" using an Agrobacterium-mediated cotyledonary-node transformation method. Overexpression of EsPHT1;4 in soybean not only promoted the increase of plant biomass and yield of transgenic plants upon low P stress, but also increased the accumulation and transportation of Pi from roots to leaves in the transgenic soybean lines. CONCLUSION: EsPHT1;4 was critical for controlling the accumulation and translocation of Pi in plants, and can be subsequently used as an effective foreign gene for the improvement of P use efficiency of crops by genetic manipulation.


Asunto(s)
Brassicaceae/metabolismo , Glycine max/crecimiento & desarrollo , Proteínas de Transporte de Fosfato/genética , Fósforo/efectos adversos , Brassicaceae/genética , Clonación Molecular , Regulación de la Expresión Génica de las Plantas , Proteínas de Transporte de Fosfato/metabolismo , Hojas de la Planta/genética , Proteínas de Plantas/genética , Raíces de Plantas/genética , Plantas Modificadas Genéticamente/crecimiento & desarrollo , Glycine max/genética , Estrés Fisiológico , Regulación hacia Arriba
8.
Microb Pathog ; 112: 171-175, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28943152

RESUMEN

In recent years Epithelial Mesenchymal Transition (EMT) has been proposed as a mechanism indispensable to acquisition of metastatic properties by tumor cells. In this study we tested the ability of Ferrerol, a Chinese herb-derived compound to ablate the EMT in human lung squamous cell carcinoma cells. Human lung squamous cell carcinoma cells, Calu-1 were treated with various concentrations of Ferrerol for 24 h to examine its effect on their viability by the MTT assay. Only those concentrations which showed least effect on the viability of Calu-1 cells were further used to evaluate the expression of epithelial and mesenchymal markers by western blotting. Furthermore the effect of such concentrations on the migration and invasion of Calu-1 cells was determined by wound healing and transwell invasion assays respectively. The results demonstrated that Ferrerol treatment led to the downregulation of Slug and Zeb-1, transcriptional regulators of EMT with the concomitant increase and decrease in the expression of E-cadherin and vimentin respectively. These data were further supported by migration and invasion assays which demonstrated that Ferrerol treatment caused inhibited the migration and invasion of Calu-1 lung squamous cell carcinoma cells. Taken together, our results indicate that Ferrerol suppresses lung squamous cell carcinoma cell metastatic potential by modulating the expression of EMT proteins.


Asunto(s)
Carcinoma de Células Escamosas , Medicamentos Herbarios Chinos/farmacología , Transición Epitelial-Mesenquimal/efectos de los fármacos , Transición Epitelial-Mesenquimal/fisiología , Neoplasias Pulmonares/tratamiento farmacológico , Transducción de Señal/efectos de los fármacos , Antígenos CD , Cadherinas/metabolismo , Línea Celular Tumoral/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Humanos , Neoplasias Pulmonares/patología , Invasividad Neoplásica , Factores de Transcripción de la Familia Snail/metabolismo , Vimentina/metabolismo , Cicatrización de Heridas , Homeobox 1 de Unión a la E-Box con Dedos de Zinc/metabolismo
9.
Chemosphere ; 169: 577-585, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27902964

RESUMEN

Characterization of phosphorus (P) pools is vital to understanding the contribution of P to water eutrophication. In this study, dissolved and particulate P classes during an algae bloom in Lake Taihu, as well as their relationships with the main environmental factors, were analyzed based on solution 31P NMR. The results showed that dissolved P was dominated by orthophosphate (Ortho-P) in heavily polluted regions and by orthophosphate monoester (Mono-P) and orthophosphate diester (Diester-P) in lightly polluted regions, indicating that the main dissolved P classes varied with the degree of lake pollution. The difference in the temporal variation patterns of dissolved P classes revealed that dissolved Ortho-P is the preferred class, and its concentration may be affected by major primary producers. It also revealed that dissolved Mono-P is prone to accumulation under the effects of algal blooms, especially in heavily polluted regions. The main particulate P classes were similar to those of dissolved P, but their variation trends were the same in different lake regions. There were significant positive correlations between the major particulate P classes and Chl a during the majority of the sampling period, indicating that living algal cells have a major contribution to particulate P. Obvious temporal variations of P classes may affect the bioavailability and dynamics of P in the water of Lake Taihu, but the particle reactivities of the main inorganic and organic P classes were similar. Therefore, they have little effect on P partitioning between the dissolved and particulate phases.


Asunto(s)
Monitoreo del Ambiente/métodos , Eutrofización , Lagos/química , Fósforo/análisis , Contaminantes Químicos del Agua/análisis , China , Espectroscopía de Resonancia Magnética , Fósforo/química , Fitoplancton/efectos de los fármacos , Fitoplancton/crecimiento & desarrollo , Solubilidad , Contaminantes Químicos del Agua/química
10.
Chin J Integr Med ; 18(8): 629-34, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22855040

RESUMEN

Adaptation is an eternal theme of biological evolution. The paper aims at exploring the conception of positive correlation between traditional Chinese medicine (TCM) and human homeostatic evolution based on medical perspective. Discussions mainly involve TCM conforming to natural laws and natural evolution of life, spontaneous harmonization of yin and yang and operating system of human self-healing, modern human immunology and human endogenous immune function in TCM, self-homeostasis of human micro-ecological state and balance mechanism on regulating base in TCM, as well as adaptation-eternal theme of biological evolution and safeguarding adaptability-value of TCM. In perspective of medicine, theory and practice of TCM are in positive correlation with human homeostatic evolution, and what TCM tries to maintain is human intrinsic adaptive capability to disease and nature. Therefore, it is the core value of TCM, which is to be further studied, explored, realized and known to the world.


Asunto(s)
Evolución Biológica , Homeostasis , Medicina Tradicional China , Adaptación Fisiológica , Humanos , Sistema Inmunológico/inmunología , Yin-Yang
11.
Zhongguo Zhong Yao Za Zhi ; 37(24): 3701-5, 2012 Dec.
Artículo en Chino | MEDLINE | ID: mdl-23627163

RESUMEN

OBJECTIVE: To screen out fungus strains with acetylcholinesterase inhibitory activity from Huperzia serrata. METHOD: Endophytic fungi fermentation products from 59 H. serrata strains were stained with acetylcholinesterase hydrolyzed alpha-naphthaleneacetic ethyl ester and fast blue B salt, and screened for acetylcholinesterase inhibitory activity with thin-layer chromatography-bioautography. Target strains were classified and identified through the sequence analysis on 18s rDNA and 5.8s rDNA combined with morphological characteristics. RESULT: Fungus strain LQ2F01 from H. serrata showed positive color reaction in the screening for acetylcholinesterase inhibitory activity. The sequence analysis on 18s rDNA and 5.8s rDNA combined with morphological characteristics showed the strain LQ2F01 belonged to Acremonium. CONCLUSION: Endophytic Fungi LQ2F01 from H. serrata shows identical acetylcholinesterase inhibitory activity with the host plant, which is of great significance to the development of natural medicines and the studies on the relationship between the endophytic gungi and the host plant.


Asunto(s)
Acetilcolinesterasa/metabolismo , Inhibidores de la Colinesterasa/metabolismo , Hongos/metabolismo , Huperzia/microbiología , Acremonium/genética , Acremonium/metabolismo , Inhibidores de la Colinesterasa/aislamiento & purificación , Cromatografía en Capa Delgada , ADN de Hongos/química , ADN de Hongos/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Compuestos de Diazonio/metabolismo , Hongos/clasificación , Hongos/genética , Hidrólisis , Ácidos Naftalenoacéticos/metabolismo , Filogenia , ARN Ribosómico 18S/clasificación , ARN Ribosómico 18S/genética , ARN Ribosómico 5.8S/clasificación , ARN Ribosómico 5.8S/genética , Análisis de Secuencia de ADN
12.
J Sci Food Agric ; 92(1): 177-83, 2012 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-21815158

RESUMEN

BACKGROUND: Aroma is one important fruit sensory attribute influenced by the volatile constituents related to species, variety and technological treatments. We analysed the variations of volatile compounds in five pear cultivars and investigated their changes related to different pear organs, different ripening stages, 1-MCP treatment and ultra-high-pressure pasteurisation. RESULTS: Considerable variations exist in the quantity of 10 volatile compounds among five pear cultivars. Their levels generally showed an increasing trend when collected at later harvest time in Ya pear. In Whangkeumbae pear, most volatile compounds reached their maximum levels in skin and pulp. After treating pears with 42 µmol L(-1) 1-methylcyclopropene (1-MCP), the levels of volatiles remained basically unchanged or only slightly increased in Ya pear during a shelf life of 21 days. When Huangguan pear juice was pasteurised by using ultra-high pressure, the levels of volatiles significantly changed during the shelf life. CONCLUSION: The volatile compositions of five different Chinese pear cultivars differ considerably. The levels of these volatiles vary along with ripening stages and pear tissues. A moderate concentration of 1-MCP could keep the levels of volatile compounds basically unchanged during storage and ultra-high-pressure pasteurisation could change the levels of volatiles significantly during the following shelf life.


Asunto(s)
Ciclopropanos/farmacología , Frutas/metabolismo , Odorantes , Pasteurización/métodos , Pyrus/metabolismo , Compuestos Orgánicos Volátiles/metabolismo , Bebidas , China , Frutas/crecimiento & desarrollo , Preparaciones de Plantas , Presión , Pyrus/clasificación , Pyrus/crecimiento & desarrollo , Especificidad de la Especie
13.
Chin J Integr Med ; 17(12): 945-9, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22139547

RESUMEN

This paper suggests a novel approach concerning the medical treatment of human beings, which appears to be economically and practically superior to either biomedicine or traditional medicine. A brand new medical system-Hehe [see text] medicine, has been proposed based on a preventive-biomedical-psycho-social treatment model. This is characterized by a dual approach in which life nurturing is consistently practised and medical treatment is applied when necessary in order to maintain a healthy life. Its core value would facilitate the self-restoration to health and self-adaptation to nature through health cultivation and medical means. Medical services would be firstly provided to the prevention of potential disease germinating in the human body, and clinical medical treatment would be the last resort of systematic medical practice. This paper discusses not only this new concept but also the advantages of traditional Chinese medicine and biomedicine, especially how both medical systems compare in cognitive style, on a cultural level, and on a technical level.


Asunto(s)
Salud , Medicina Tradicional China , Medicina , Cognición , Humanos , Medicina Integrativa
16.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 26(11): 1042-4, 2006 Nov.
Artículo en Chino | MEDLINE | ID: mdl-17186741

RESUMEN

By analyzing the East-West difference in psychology and thinking patterns, the author compared the frequency of conventional words applied and the usage of subtitle, as well as the selection of sentence structure in title of articles, and thus advocated that the differences of attention psychology and thinking patterns, linear in the West and spiral in China, were the primary causes for different expressions of articles' title.


Asunto(s)
Lenguaje , Publicaciones Periódicas como Asunto , Traducciones , China , Difusión de la Información
17.
Planta ; 220(1): 87-96, 2004 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15309534

RESUMEN

In order to functionally analyze the predicted defensive role of leaf polyphenol oxidase (PPO; EC 1.10.3.1) in Populus, transgenic hybrid aspen (Populus tremula x P. alba) plants overexpressing a hybrid poplar (Populus trichocarpa x P. deltoides) PtdPPO1 gene were constructed. Regenerated transgenic plants showed high PPO enzyme activity, PtdPPO1 mRNA levels and PPO protein accumulation. In leaf disk bioassays, forest tent caterpillar (Malacosoma disstria) larvae feeding on PPO-overexpressing transgenics experienced significantly higher mortality and reduced average weight gain compared to larvae feeding on control leaves. However, this effect was observed only when older egg masses were used and the resulting larvae showed reduced growth and vigor. In choice tests, no effect of PPO overexpression was detected. Although PPO in poplar leaves is latent and requires activation with detergents or trypsin for full enzymatic activity, in caterpillar frass the enzyme was extracted in the fully activated form. This activation correlated with partial proteolytic cleavage, suggesting that PPO latency and activation during digestion could be an adaptive and defense-related feature of poplar PPO.


Asunto(s)
Catecol Oxidasa/genética , Lepidópteros/patogenicidad , Populus/enzimología , Animales , Catecol Oxidasa/metabolismo , Cruzamientos Genéticos , Inmunidad Innata/genética , Enfermedades de las Plantas/parasitología , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/metabolismo , Hojas de la Planta/enzimología , Hojas de la Planta/parasitología , Plantas Modificadas Genéticamente/enzimología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA