Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 54
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Foods ; 11(8)2022 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-35454654

RESUMO

In recent years, a variety of double protein dairy products have appeared on the market. It is a dairy product made by replacing parts of animal protein with plant protein and then using certain production methods. For some countries with limited milk resources, insufficient protein intake and low income, double protein dairy products have a bright future. More and more studies have found that double protein dairy products have combined effects which can alleviate the relatively poor functional properties of plant protein, including solubility, foaming, emulsifying and gelling. In addition, the taste of plant protein has been improved. This review focuses on the current state of research on double protein dairy products. It covers some salient features in the science and technology of plant proteins and suggests strategies for improving their use in various food applications. At the same time, it is expected that the fermentation methods used for those traditional dairy products as well as other processing technologies could be applied to produce novelty foods based on plant proteins.

2.
Sci Rep ; 10(1): 2388, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-32024923

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

3.
Front Plant Sci ; 9: 809, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29997634

RESUMO

Plant WRKY transcription factors (TFs) are active guardians against pathogens' insurgency, key components in developmental processes, contributors in signal transduction pathways, and regulators of diverse biotic and abiotic stress responses. In this research, we isolated, cloned, and functionally characterized a new WRKY TF GmWRKY49 from soybean. GmWRKY49 is a nuclear protein which contains two highly conserved WRKY domains and a C2H2-type zinc-finger structure. The normalized expression (log2 ratio) of GmWRKY49 was 2.75- and 1.90-fold in salt-tolerant and salt-susceptible soybean genotypes, respectively. The transcripts of GmWRKY49 could be detected in roots, stems, leaves, flowers, and almost no expression in pod tissues. The salinity-tolerance response of this gene was studied through overexpression in soybean composite seedlings and transgenic Arabidopsis. The effect of GmWRKY49 overexpression on root length of transgenic Arabidopsis was also investigated. Under salt stress, several parameters including germination rate, survival rate, root length, rosette diameter, relative electrolyte leakage, and proline content were significantly higher in composite seedlings and transgenic Arabidopsis than those in wild-type. Moreover, GmWRKY49 enhanced salinity tolerance in soybean mosaic seedlings and transgenic Arabidopsis. These results suggest that GmWRKY49 is a positive regulator of salinity tolerance in soybean and has high potential utilization for crop improvement.

4.
Sci Rep ; 7(1): 4106, 2017 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-28646139

RESUMO

In different plant species, aquaporins (AQPs) facilitate water movement by regulating root hydraulic conductivity under diverse stress conditions such as salt and water stresses. To improve survival and yield of crop plants, a detailed understanding of stress responses is imperative and required. We used Glycine soja genome as a tool to study AQPs, considering it shows abundant genetic diversity and higher salt environment tolerance features and identified 62 Gs AQP genes. Additionally, this study identifies major aquaporins responsive to salt and drought stresses in soybean and elucidates their mode of action through yeast two-hybrid assay and BiFC. Under stress condition, the expression analysis of AQPs in roots and leaves of two contrasting ecotypes of soybean revealed diverse expression patterns suggesting complex regulation at transcriptional level. Based on expression analysis, we identify GmTIP2;1 as a potential candidate involved in salinity and drought responses. The overexpression of GmTIP2;1 in Saccharomyces cerevisiae as well as in-planta enhanced salt and drought tolerance. We identified that GmTIP2;1 forms homodimers as well as interacts with GmTIP1;7 and GmTIP1;8. This study augments our knowledge of stress responsive pathways and also establishes GmTIP2;1 as a new stress responsive gene in imparting salt stress tolerance in soybean.


Assuntos
Aquaporinas/genética , Regulação da Expressão Gênica de Plantas , Estudo de Associação Genômica Ampla , Glycine max/genética , Glycine max/metabolismo , Salinidade , Estresse Fisiológico , Água , Adaptação Biológica/genética , Motivos de Aminoácidos , Sequência de Aminoácidos , Aquaporinas/química , Aquaporinas/metabolismo , Biologia Computacional/métodos , Secas , Família Multigênica , Especificidade de Órgãos , Regiões Promotoras Genéticas , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Estresse Fisiológico/genética
5.
Front Plant Sci ; 7: 1111, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27551283

RESUMO

Photosynthesis limitation by CO2 flow constraints from sub-stomatal cavities to carboxylation sites in chloroplasts under drought stress conditions is, at least in some plant species or crops not fully understood, yet. Leaf mesophyll conductance for CO2 (gm) may considerably affect both photosynthesis and water use efficiency (WUE) in plants under drought conditions. The aim of our study was to detect the responses of gm in leaves of four winter wheat (Triticum aestivum L.) genotypes from different origins under long-term progressive drought. Based on the measurement of gas-exchange parameters the variability of genotypic responses was analyzed at stomatal (stomata closure) and non-stomatal (diffusional and biochemical) limits of net CO2 assimilation rate (AN). In general, progressive drought caused an increasing leaf diffusion resistance against CO2 flow leading to the decrease of AN, gm and stomatal conductance (gs), respectively. Reduction of gm also led to inhibition of carboxylation efficiency (Vcmax). On the basis of achieved results a strong positive relationship between gm and gs was found out indicating a co-regulation and mutual independence of the relationship under the drought conditions. In severely stressed plants, the stomatal limitation of the CO2 assimilation rate was progressively increased, but to a less extent in comparison to gm, while a non-stomatal limitation became more dominant due to the prolonged drought. Mesophyll conductance (gm) seems to be a suitable mechanism and parameter for selection of improved diffusional properties and photosynthetic carbon assimilation in C3 plants, thus explaining their better photosynthetic performance at a whole plant level during periods of drought.

6.
Sci Total Environ ; 569-570: 1077-1086, 2016 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-27396318

RESUMO

Coastal mudflat areas are regarded as the important reserve land resource in China. Rational exploitation and development of the mudflat areas can relieve the stress of inadequate land resources. Probing into the developing models of resource exploitation of coastal tidal mudflats is one of the important components of achieving the sustainable development in the coastal areas. Therefore, the development history of coastal mudflats after 1950s in China is briefly introduced in this paper. Then, the status in quo of the modes of development and utilization of coastal mudflat in China the paper is reviewed with a special attention payed to the agricultural use of coastal resource, especially halophytes and improved salt-tolerant varieties planting, agricultural dyke pond and coastal saline-alkali soil remediation. Based on related research frontier, sustainable developmental prospects of these coastal areas are presented as well.

7.
Int J Clin Exp Med ; 8(8): 12935-41, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26550211

RESUMO

BACKGROUND: Published literatures report controversial results about the effect of combined treatment with alendronate and alfacalcidol for the prevention of fractures in osteoporosis patients. METHODS: Seven common databases were searched for related randomized controlled trials published up to April, 2015. Bayesian random effects network meta-analysis was used to assess the pairwise odds ratios (OR), 95% credible intervals (CI). RESULTS: Thirteen randomized controlled trials were identified (3710 patients). The network meta-analysis results indicated that combining treatment with alendronate and alfacalcidol was significantly better to prevent bone fractures in osteoporosis patients than alendronate (OR=0.53, 95% CI: 0.19-0.95) and alfacalcidol (OR=0.25, 95% CI: 0.08-0.49). In addition, there was no significant difference for adverse events among the three therapeutic regimen. CONCLUSIONS: Combined treatment with alendronate and alfacalcidol was more active than the monotherapies in preventing bone fractures in osteoporosis patients. Large-scale randomized, controlled trials are recommended to confirm the result.

8.
Front Plant Sci ; 6: 792, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26483809

RESUMO

Proline accumulation is a common response to salt stress in many plants. Salt stress also increased proline concentration in roots, stems, and leaves of Kosteletzkya virginica seedling treated with 300 mM NaCl for 24 h and reached 3.75-, 4.76-, and 6.83-fold higher than controls. Further study on proline content in leaves under salt stress showed that proline content increased with increasing NaCl concentrations or time. The proline level peaked at 300 mM NaCl for 24 h and reached more than sixfold higher than control, but at 400 mM NaCl for 24 h proline content fell back slightly along with wilting symptom. To explore the cause behind proline accumulation, we first cloned full length genes related to proline metabolism including KvP5CS1, KvOAT, KvPDH, and KvProT from K. virginica and investigated their expression profiles. The results revealed that the expressions of KvP5CS1 and KvProT were sharply up-regulated by salt stress and the expression of KvOAT showed a slight increase with increasing salt concentrations or time, while the expression of KvPDH was not changed much and slightly decreased before 12 h and then returned to the original level. As the key enzyme genes for proline biosynthesis, the up-regulated expression of KvP5CS1 played a more important role than KvOAT for proline accumulation in leaves under salt stress. The low expression of KvPDH for proline catabolism also made a contribution to proline accumulation before 12 h.

9.
ScientificWorldJournal ; 2014: 954849, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25302337

RESUMO

Recently, the frequent seasonal drought in Southwest China has brought considerable concerns and continuous heated arguments on the "water pump" viewpoint (i.e., the water demand from Hevea spp. and Eucalyptus spp. can be treated as a water pump) once again. However, such viewpoint just focused on water consumption from vegetation transpiration and its ecoenvironment impacts, which had not considered other attributes of vegetation, namely, water saving and drought resistance, and hydrological regulation (water conservation) into consideration. Thus, in this paper, the synthesized attributes of regional vegetation water use had been mainly discussed. The results showed that the study on such aspects as the characters of water consumption from vegetation transpiration, the potential of water saving and drought resistance, and the effects of hydrological regulation in Southwest China lagged far behind, let alone the report on synthesized attributes of water utilization with the organic combination of the three aspects above or the paralleled analysis. Accordingly, in this paper, the study on the synthesized attributes of water use by regional vegetation in Southwest China was suggested, and the objectives of such a special study were clarified, targeting the following aspects: (i) characters of water consumption from transpiration of regional typical artificial vegetation; (ii) potential of water saving and drought resistance of regional typical artificial vegetation; (iii) effects of hydrological regulation of regional typical artificial vegetation; (iv) synthesized attributes of water use by regional typical artificial vegetation. It is expected to provide a new idea for the scientific assessment on the regional vegetation ecoenvironment effects and theoretical guidance for the regional vegetation reconstruction and ecological restoration.


Assuntos
Eucalyptus/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Hevea/metabolismo , Água/metabolismo , Adaptação Fisiológica , Transporte Biológico , China , Conservação dos Recursos Naturais , Secas , Ecossistema , Monitoramento Ambiental , Eucalyptus/genética , Eucalyptus/crescimento & desenvolvimento , Hevea/genética , Hevea/crescimento & desenvolvimento , Transdução de Sinais , Solo
10.
Plant Physiol Biochem ; 81: 74-83, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24491798

RESUMO

The chloroplastic glutamine synthetase (GS, EC 6.3.1.2) activity was previously shown to be the limiting step of photorespiratory pathway. In our experiment, we examined the photosynthetic high-light responses of the GS2-mutant of barley (Hordeum vulgare L.) with reduced GS activity, in comparison to wild type (WT). The biophysical methods based on slow and fast chlorophyll fluorescence induction, P700 absorbance, and gas exchange measurements were employed. Despite the GS2 plants had high basal fluorescence (F0) and low maximum quantum yield (Fv/Fm), the CO2 assimilation rate, the PSII and PSI actual quantum yields were normal. On the other hand, in high light conditions the GS2 had much higher non-photochemical quenching (NPQ), caused both by enhanced capacity of energy-dependent quenching and disconnection of PSII antennae from reaction centers (RC). GS2 leaves also maintained the PSII redox poise (QA(-)/QA total) at very low level; probably this was reason why the observed photoinhibitory damage was not significantly above WT. The analysis of fast chlorophyll fluorescence induction uncovered in GS2 leaves substantially lower RC to antenna ratio (RC/ABS), low PSII/PSI ratio (confirmed by P700 records) as well as low PSII excitonic connectivity.


Assuntos
Glutamato-Amônia Ligase/metabolismo , Hordeum/enzimologia , Fotossíntese/fisiologia , Dióxido de Carbono/metabolismo , Respiração Celular , Clorofila/metabolismo , Fluorescência , Glutamato-Amônia Ligase/genética , Hordeum/genética , Hordeum/fisiologia , Hordeum/efeitos da radiação , Luz , Complexos de Proteínas Captadores de Luz/metabolismo , Mutação , Oxirredução , Fotossíntese/efeitos da radiação , Complexo de Proteína do Fotossistema I/genética , Complexo de Proteína do Fotossistema I/metabolismo , Complexo de Proteína do Fotossistema II/genética , Complexo de Proteína do Fotossistema II/metabolismo , Folhas de Planta/enzimologia , Folhas de Planta/genética , Folhas de Planta/fisiologia , Folhas de Planta/efeitos da radiação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
11.
J Photochem Photobiol B ; 137: 107-15, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24508481

RESUMO

In conditions of long-lasting moderate drought stress, we have studied the photoprotective responses in leaves of wheat (Triticum aestivum L., cv. Katya) related to the photosynthetic electron and proton transport. The dark-interval relaxation kinetics of electrochromic bandshift (ECS) indicated a decrease of electric and an increase of osmotic component of the proton motive force in drought stressed leaves, but neither the total proton motive force (pmf) nor the thylakoid proton conductance (gH(+)) were affected. We observed the enhanced protection against overreduction of PSI acceptor side in leaves of drought stressed plants. This was obviously achieved by the rapid buildup of transthylakoid pH gradient at relatively low light intensities, directly associated to the steep increase of NPQ and the down-regulation of linear electron transport. It was further accompanied by the steep increase of redox poise at PSII acceptor side and PSI donor side. The early responses related to thylakoid lumen acidification in drought-stressed leaves could be associated with the activity of an enhanced fraction of PSI not involved in linear electron flow, which may have led to enhanced cyclic electron pathway even in relatively low light intensities, as well as to the drought-induced decrease of IP-amplitude in fast chlorophyll fluorescence kinetics.


Assuntos
Folhas de Planta/metabolismo , Prótons , Estresse Fisiológico , Triticum/metabolismo , Clorofila/metabolismo , Transporte de Elétrons/efeitos da radiação , Cinética , Luz , Complexo de Proteína do Fotossistema II/metabolismo , Folhas de Planta/fisiologia , Folhas de Planta/efeitos da radiação , Estresse Fisiológico/efeitos da radiação , Fatores de Tempo , Triticum/fisiologia , Triticum/efeitos da radiação
13.
Ying Yong Sheng Tai Xue Bao ; 24(9): 2423-30, 2013 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-24417097

RESUMO

Soil salinity and groundwater depth are the two important factors affecting the vegetation growth and distribution in the Yellow River Delta. Through field investigation and statistical analysis, this paper studied the relationships between the typical vegetations (Suaeda heteroptera-Tamarix chinensis, Robinia pseudoacacia, Phragmites australis, and cotton) , soil salinity, and groundwater depth in the Delta. In the study area, groundwater depth had significant effects on soil salinity, with the average influence coefficient being 0.327. When the groundwater depth was 0.5-1.5 m, soil salinization was most severe. The vegetation growth in the Delta was poorer, with the NDVI in 78% of the total area being less than 0.4. Groundwater depth and soil salinity had significant effects on the vegetation distribution. Soil salinity had significant effects on the NDVI of R. pseudoacacia, S. heteroptera-T. chinensis, P. australis, and cotton, while groundwater depth had significant effects on the NDVI of S. heteroptera - T. chinensis, but lesser effects on the NDVI of P. australis, cotton and R. pseudoacacia.


Assuntos
Água Subterrânea , Desenvolvimento Vegetal , Solo/química , Áreas Alagadas , Chenopodiaceae/crescimento & desenvolvimento , China , Gossypium/crescimento & desenvolvimento , Poaceae/crescimento & desenvolvimento , Rios , Robinia/crescimento & desenvolvimento , Salinidade , Tamaricaceae/crescimento & desenvolvimento
14.
Zhonghua Shao Shang Za Zhi ; 28(4): 244-7, 2012 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-23248957

RESUMO

OBJECTIVE: To observe the clinical effect of the concentrated suture fixation method on skin transplantation on deep burn wound or wound of cicatricial deformity after burn in the jaw and neck region. METHODS: One hundred and fourteen patients, hospitalized from April 2002 to December 2011, with deep burn or cicatricial deformity after burn in the jaw and neck region, were divided into packaging group and concentrated suture group according to the random number table. Each group had 57 patients including 48 cases with deep burn and 9 cases with cicatricial deformity. Traditional suture-package fixation method and concentrated suture fixation method were respectively used in packaging group and concentrated suture group to fix the autologous medium split-thickness skin in transplantation on wounds or scars. On post operation day (POD) 14, the skin microcirculatory perfusion flow of skin graft was measured, and the occurrence of ecchymoma, infection, and necrosis of skin in operative region were observed. The elasticity and contracture of grafted skin and scar hyperplasia on wound edge were observed 6 months after operation. Measurement data were processed with u test, while enumeration data with Fisher's exact test or Chi-square test. RESULTS: (1) On POD 14, the skin microcirculatory perfusion flow in concentrated suture group [(2.86 +/- 0.8) V] was significantly higher than that in packaging group [(2.33 +/- 0.15) V, u = 17.776, P < 0.05]. (2) Ecchymoma occurred in 4 patients of packaging group and 3 patients of concentrated suture group, but the difference between two groups was not statistically significant (chi 2 = 0.152, P > 0.05). (3) Infection in operative region was observed in 1 patient of packaging group, while no patient in concentrated suture group showed this symptom. The difference between two groups was not statistically significant (P > 0.05). (4) Grafted skin in 6 patients of packaging group showed foliated necrosis, which was not observed on those of patients in concentrated suture group. The difference between two groups was statistically significant (P < 0.05). (5) Centipede leg-like scar hyperplasia on wound edge occurred in 21 patients in packaging group and 6 patients in concentrated suture group, and the difference between two groups was statistically significant (chi 2 = 10.920, P < 0.05). (6) Poor elasticity of grafted skin was detected in 17 patients of packaging group and 4 patients of concentrated suture group, and the difference between two groups was statistically significant (chi 2 = 9.865, P < 0.05). (7) Obvious contracture of grafted skin was observed in 15 patients of packaging group and 4 patients of concentrated suture group, and the difference between two groups was statistically significant (chi 2 = 11.684, P < 0.05). CONCLUSIONS: Concentrated suture fixation method is suitable for application in transplantation of big sheet skin on wound in the jaw and neck region. It has high survival rate and is convenient for postoperative observation.


Assuntos
Queimaduras/cirurgia , Transplante de Pele/métodos , Suturas , Adulto , Cicatriz/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pescoço/cirurgia , Procedimentos Cirúrgicos Ortognáticos , Transplante Autólogo , Resultado do Tratamento
15.
Zhonghua Shao Shang Za Zhi ; 28(3): 173-7, 2012 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-22967971

RESUMO

OBJECTIVE: To study the influence of high-voltage electric burn on the microcirculation of heart in rabbit. METHODS: One-hundred and twenty New Zealand rabbits of clean grade were divided into control group (C) and electric burn group (EB) according to the random number table, with 60 rabbits in each group. Rabbits in EB group were subjected to high-voltage electric burn (the electrical current flow into the left foreleg at the lateral side of proximal end and out from the corresponding site of the right hind leg) with voltage regulator and experimental transformer. Rabbits in C group were sham injured with the same devices without electrification. At 15 minutes before injury, and 5 minutes, 1, 2, 4, 8 hour (s) post injury (PIM or PIH), ten rabbits in each group were chosen to examine the cardiac apex microcirculation hemoperfusion (CAMH) with laser Doppler hemoperfusion image instrument. The morphologic changes of microvessels of left ventricular wall tissues of 2 rabbits from each of the 10 rabbits collected at above-mentioned time points were observed with light microscope and transmission electron microscope. Auricular vein blood of rabbit was harvested at above-mentioned time points for the determination of aspartate amino transferase (AST), lactate dehydrogenase (LDH), hydroxybutyrate dehydrogenase (HBDH), creatine kinase (CK), and creatine kinase isozyme MB (CK-MB) by full-automatic biochemical analyzer. Data were processed with two-factor analysis of variance and LSD test. RESULTS: (1) The differences between C group and EB group in detection results were statistically significant, with F values from 425.991 to 3046.834, P values all below 0.01. Only the data within EB group were comparable. (2) At PIM 5, the CAMH value of rabbits in EB group was (1.96 ± 0.09) V, which was lower than that at 15 minutes before injury [(4.34 ± 0.35) V, P < 0.01]. The CAMH value of rabbits in EB group was increased at PIH 1 [(3.43 ± 0.30) V], and then it showed a tendency of decrease. (3) Bleeding and microthrombus formation were observed in venule and capillary vessel of rabbits in EB group at PIH 8. Breakage of basement membrane of capillary endothelial cells, mitochondrial swelling, and severe degranulation from damaged endoplasmic reticulum were observed in rabbits of EB group at PIH 8. (4) Levels of AST, LDH, HBDH, CK, and CK-MB in rabbits of EB group were significantly higher at PIH 1, 2, 4, 8 than at 15 minutes before injury (with P values all below 0.01). The AST level peaked at PIH 2 [(164 ± 39) U/L]. Levels of LDH and HBDH peaked at PIH 4, which were respectively (1016 ± 246) U/L and (487 ± 54) U/L. The CK level peaked at PIH 8 [(7799 ± 738) U/L]. The CK-MB level peaked at PIH 2 [(1848 ± 65) U/L]. CONCLUSIONS: High-voltage electric burn can bring damage to the microvessels of heart in rabbits and change blood flow of microcirculation, which should be given adequate attention during the treatment.


Assuntos
Queimaduras por Corrente Elétrica/fisiopatologia , Coração/fisiopatologia , Microcirculação , Animais , Hemodinâmica , Coelhos
16.
Crit Rev Biotechnol ; 32(1): 1-21, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21699437

RESUMO

Global warming is one of the most serious challenges facing us today. It may be linked to the increase in atmospheric CO2 and other greenhouse gases (GHGs), leading to a rise in sea level, notable shifts in ecosystems, and in the frequency and intensity of wild fires. There is a strong interest in stabilizing the atmospheric concentration of CO2 and other GHGs by decreasing carbon emission and/or increasing carbon sequestration. Biotic sequestration is an important and effective strategy to mitigate the effects of rising atmospheric CO2 concentrations by increasing carbon sequestration and storage capacity of ecosystems using plant photosynthesis and by decreasing carbon emission using biofuel rather than fossil fuel. Improvement of photosynthetic carbon assimilation, using transgenic engineering, potentially provides a set of available and effective tools for enhancing plant carbon sequestration. In this review, firstly different biological methods of CO2 assimilation in C3, C4 and CAM plants are introduced and three types of C4 pathways which have high photosynthetic performance and have evolved as CO2 pumps are briefly summarized. Then (i) the improvement of photosynthetic carbon assimilation of C3 plants by transgenic engineering using non-C4 genes, and (ii) the overexpression of individual or multiple C4 cycle photosynthetic genes (PEPC, PPDK, PCK, NADP-ME and NADP-MDH) in transgenic C3 plants (e.g. tobacco, potato, rice and Arabidopsis) are highlighted. Some transgenic C3 plants (e.g. tobacco, rice and Arabidopsis) overexpressing the FBP/SBPase, ictB and cytochrome c6 genes showed positive effects on photosynthetic efficiency and growth characteristics. However, over the last 28 years, efforts to overexpress individual, double or multiple C4 enzymes in C3 plants like tobacco, potato, rice, and Arabidopsis have produced mixed results that do not confirm or eliminate the possibility of improving photosynthesis of C3 plants by this approach. Finally, a prospect is provided on the challenges of enhancing carbon assimilation of C3 plants using transgenic engineering in the face of global warming, and the trends of the most promising approaches to improving the photosynthetic performance of C3 plants.


Assuntos
Carbono/metabolismo , Engenharia Genética/métodos , Fotossíntese , Plantas Geneticamente Modificadas/metabolismo , Plantas/metabolismo , Aquecimento Global , Plantas/genética , Plantas Geneticamente Modificadas/genética
17.
PLoS One ; 6(5): e18718, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21637338

RESUMO

BACKGROUND: Seven serine/threonine kinase genes have been predicted in unicellular cyanobacterium Synechocystis sp. PCC6803. SpkA and SpkB were shown to be required for cell motility and SpkE has no kinase activity. There is no report whether the other four STKs are involved in stress-mediated signaling in Synechocystis PCC6803. METHODOLOGY/PRINCIPAL FINDINGS: In this paper, we examined differential expression of the other four serine/threonine kinases, SpkC, SpkD, SpkF and SpkG, at seven different stress conditions. The transcriptional level was up-regulated of spkG and down-regulated of spkC under high salt stress condition. Two spk deletion mutants, ΔspkC and ΔspkG, were constructed and their growth characteristic were examined compared to the wild strain. The wild strain and ΔspkC mutant were not affected under high salt stress conditions. In contrast, growth of spkG mutant was completely impaired. To further confirm the function of spkG, we also examined the effect of mutation of spkG on the expression of salt stress-inducible genes. We compared genome-wide patterns of transcription between wild-type Synechocystis sp. PCC6803 and cells with a mutation in the SpkG with DNA microarray analysis. CONCLUSION: In this study, we first study the spkG gene as sensor of high salt signal. We consider that SpkG play essential roles in Synechocystis sp. for sensing the high salt signal directly, rather than mediating signals among other kinases. Our microarray experiment may help select relatively significant genes for further research on mechanisms of signal transduction of Synechocystis sp. PCC6803 under high salt stress.


Assuntos
Proteínas Serina-Treonina Quinases/metabolismo , Cloreto de Sódio/farmacologia , Synechocystis/efeitos dos fármacos , Synechocystis/enzimologia , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Genes Bacterianos/genética , Mutagênese Insercional/efeitos dos fármacos , Mutagênese Insercional/genética , Mutação/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Repressoras/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Synechocystis/genética , Synechocystis/crescimento & desenvolvimento , Transcrição Gênica/efeitos dos fármacos
18.
Electron. j. biotechnol ; 14(3): 4-4, May 2011. ilus, tab
Artigo em Inglês | LILACS | ID: lil-602981

RESUMO

The changes of cell ultra structure as well as Ca2+ homeostasis involved in the drought-induced maize leaf senescence was investigated. Meanwhile, many indicatives of leaf senescence including thiobarbituric acid reactive substance (MDA), electrolyte leakage (EL), and chlorophyll along with soluble proteins were also detected during the process. The Polyethylene glycol6000(PEG6000)-incubated detached leaves showed a slight increase in the MDA content and electrolyte leakage during the first 30 min of our detection, which was corresponded to an unobvious alteration of the cell ultrastructure. Other typical senescence parameters measured in whole leaf exhibited a moderate elevation as well. Thereafter, however, the EL and MDA rose to a large extent, which was correlated with a dramatic damage to the cell ultrastructure with concomitant sharp decrease in the chlorophyll and soluble proteins content. The deposits of calcium antimonite, being an indicator for Ca2+ localization, were observed in the vacuoles as well as intercellular spaces in the leaves grown under normal condition. Nevertheless, after PEG treatment, it was revealed a distinct increment of Ca2+ in the cytoplasm as well as chloroplasts and nuclei. Moreover, with long-lasting treatment of PEG to the detached leaves, the concentration of Ca2+ as described above showed a continuous increment which was consist with the remarked alteration of physiological parameters and severe damage to the ultrastructure of cells, all of which indicated the leaf senescence. Such drought-induced leaf senescence might result from a loss of the cell's capability to extrude Ca2+. All above findings give us a good insight into the important role of Ca2+ homeostasis in the process of leaf senescence accelerated by the drought stress.


Assuntos
Cálcio , Senescência Celular , Secas , Folhas de Planta , Zea mays , Clorofila/análise , Eletrólitos , Homeostase , Peroxidação de Lipídeos , Células do Mesofilo , Estresse Fisiológico , Transdução de Sinais
20.
J Zhejiang Univ Sci B ; 11(11): 862-70, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21043055

RESUMO

A transgenic barley line (LSY-11-1-1) with overexpressed Phalaris coerulescens thioredoxin gene (PTrx) was employed to measure the growth, protein oxidation, cell viability, and antioxidase activity in barley roots during germination on the presence of 2 mmol/L AlCl(3) on filter paper. The results show that (1) compared with the non-transgenic barley, LSY-11-1-1 had enhanced root growth, although both were seriously inhibited after AlCl(3) treatment; (2) the degree of protein oxidation and loss of cell viability in roots of LSY-11-1-1 were much less than those in roots of non-transgenic barley, as reflected by lower contents of protein carbonyl and Evans blue uptakes in LSY-11-1-1; (3) activities of catalase (CAT), glutathione peroxidase (GPX), ascorbate peroxidase (APX), and glutathione reductase (GR) in LSY-11-1-1 root tips were generally higher than those in non-transgenic barley root tips, although these antioxidase activities gave a rise to different degrees in both LSY-11-1-1 and non-transgenic barley under aluminum stress. These results indicate that overexpressing PTrx could efficiently protect barley roots from oxidative injury by increasing antioxidase activity, thereby quenching ROS caused by AlCl(3) during germination. These properties raise the possibility that transgenic barley with overexpressed PTrx may be used to reduce the aluminum toxicity in acid soils.


Assuntos
Alumínio/farmacologia , Germinação/fisiologia , Hordeum/fisiologia , Phalaris/genética , Raízes de Plantas/fisiologia , Plantas Geneticamente Modificadas/fisiologia , Tiorredoxinas/fisiologia , Resistência a Medicamentos/efeitos dos fármacos , Resistência a Medicamentos/fisiologia , Melhoramento Genético/métodos , Germinação/efeitos dos fármacos , Hordeum/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Plantas Geneticamente Modificadas/efeitos dos fármacos , Transfecção
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...