High frequency, cell type-specific visualization of fluorescent-tagged genomic sites in interphase and mitotic cells of living Arabidopsis plants

Background  

Interphase chromosome organization and dynamics can be studied in living cells using fluorescent tagging techniques that exploit bacterial operator/repressor systems and auto-fluorescent proteins. A nuclear-localized Repressor Protein-Fluorescent Protein (RP-FP) fusion protein binds to operator repeats integrated as transgene arrays at defined locations in the genome. Under a fluorescence microscope, the tagged sites appear as bright fluorescent dots in living cells. This technique has been used successfully in plants, but is often hampered by low expression of genes encoding RP-FP fusion proteins, perhaps owing to one or more gene silencing mechanisms that are prevalent in plant cells.     

Potential hazard characteristics of Tilia, Betula, and Acer trees removed in the Helsinki City Area during 2001–2003

In order to study decay, and to improve the management and protection of old urban trees, a total of 256 felled urban trees were examined during 2001–2003: 95 Tilia spp., 74 Betula spp., and 87 Acer spp. Most of the trees (73%) were located in the main parks and along the main streets in the downtown area of Helsinki City, Finland. The mean age of the trees was over 60 years, and the majority (64%) were old park trees. Poor condition and increasing risk of failure were the main reasons for felling in 82% of the cases. Thirty three percent of these trees were degenerated or dead, but the amenity value of 14% of the risk trees was still high. The latter were old, big trees which posed a potential hazard, but had a vital and balanced crown.Some characteristic profiles for potential failure were identified for each of the tree species studied: Ganoderma lipsiense in the butts and hollows in the stems of Tilia spp., weak fork formations together with Rigidoporus populinus on Acer spp., and degeneration together with decay in the stem on Betula spp.Decay fungi most commonly identified were R. populinus, G. lipsiense, Inonotus obliquus and Piptoporus betulinus. In addition, Kretzschmaria deusta was very common in three of the parks, and on every one of the tree species investigated.     

Comparison of S-RNase,RNase T1, T2, and A effects on growth inhibition and RNA degradation of in vitro-cultured pear pollen

To obtain the basic information on fruit set regulation, effects of several RNases including S-RNase on pollen tube growth and RNA degradation in the tube were studied in the pear. Purified S-RNase from the Japanese pear ‘Kosui’ (S₄S₅) predominantly inhibited the growth of ‘Kosui’ pollen tubes (self) in vitro at 0.28 unit μL⁻¹, but it inhibited ‘Chojuro’ (S₂S₃) pollen (cross) only slightly. The same unit of RNase T₁ (EC 3.1.27.3) clearly inhibited the pollen tube growth, but the action was significantly weaker than that of the S-RNase against the self-pollen. Inhibitory effect of RNase T₂ (EC 3.1.27.1) and RNase A (EC 3.1.27.5) was only slight. The proteins other than the S-RNase extracted from pear style did not have any inhibitory action, though they possessed RNase activity 3.8 times higher than S-RNase. Thus, RNases tested here could not substitute for the S-RNase in specific inhibition against the self-pollen tube growth. Total RNA degradation by each RNase occurred in the pollen tubes as following order; S-RNase (self) ≥T₁ > T₂ ≥ A > S-RNase (cross). Degradation degree of 28S and 18S rRNA was as follows; S-RNase (self) > A > T₁ > T₂ > S-RNase (cross). The degradation of 5.8S and 5S rRNA was; S-RNase (self) > S-RNase (cross) > A > T₂ > T_1. The degree of rRNA degradation was, thus, not always in parallel with the degree of pollen growth inhibition. The S-RNase may degrade not only rRNA but also mRNA essential for pollen tube growth, and may be specifically adapted to inhibit the growth of self-pollen tubes. Therefore, controlling S-RNase amount in the style will produce self-thinning cultivars efficiently, which are unnecessary not only for hand-pollination but fruit-thinning practices in the pear. Practically, cultivar with weak self-incompatibility and small amount of S-RNase, such as ‘Okusankichi’, may be an expecting candidate for breeding self-thinning cultivars.     

Effects of CO2, temperature and their interaction on the growth, development and yield of cauliflower (Brassica oleracea L. botrytis)

Stands of summer cauliflower were grown within polyethylene-covered tunnels along which a temperature gradient was imposed. Two tunnels were maintained at either normal or elevated CO₂ concentrations. At the last harvest (88 days from transplanting) no interaction between CO₂ and temperature on total biomass was detected. The total dry weight of plants grown at 531 μmol mol⁻¹ CO₂ was 34% greater than those grown at 328 μmol mol⁻¹ CO₂, whereas a 1 °C rise reduced dry weight by 6%. From serial harvests the radiation conversion coefficient was 2.01 g MJ⁻¹ and 1.42 g MJ⁻¹ at 531 μmol mol⁻¹ CO₂and 328 μmol mol⁻¹ CO₂, respectively, but was not greatly affected by differences in temperature. No effect of either CO₂ or temperature on the canopy light extinction coefficient was detected. The rate of progress towards curd initiation increased to a maximum at 15.5 °C, and declined thereafter. Provided the effect of temperature was accounted for, CO₂ enrichment did not affect the time of curd initiation. From serial harvests after curd initiation, the logarithm of curd weight or diameter were negative linear functions of mean temperature from initiation. Increases in curd weight and diameter at 531 compared with 328 μmol mol⁻¹ CO₂ were greater at warmer temperatures (27% at 13 °C compared with 47% at 15 °C, 57 days after initiation). Effects of CO₂ on curd diameter were less than those on curd dry weight because the curd dry matter content was greater at 531 compared with 328 μmol mol⁻¹ CO₂. Thus, the effects of elevated CO₂ concentrations on fresh weight based yield parameters of cauliflower were less than the increase in total dry matter production.     

Refining the accessibility evaluation of urban green spaces with multiple sources of mobility data: A case study in Shenzhen,China

Urban green space (UGS) is an important component of urban resources which contributes to human physical and mental health. Studies on the accessibility of UGS under the two-step floating catchment (2SFCA) framework have recently received much attention. However, the effects of people’s actual mobility patterns have not been fully considered in current studies. Proposed in this study is an improved accessibility model called AM-Ga2SFCA, which refines the traditional Gaussian 2SFCA method with the actual mobility information extracted from mobile phone big data and online map. A new attractiveness index of UGS is implemented by combining the popularity evaluated by the PageRank algorithm and the actual utilisation based on buffer analysis. In addition, realistic travel time between each demand point and UGS is retrieved from the online map, which is further introduced into AM-Ga2SFCA as the travel cost. A case study is conducted in Shenzhen, China to validate the proposed model. Results show that the accessibility of UGS is strongly correlated with regional urbanization level, for example, higher accessibility generally occurred in the region with developed transportation and rich green resources. From the perspective of age groups and travel modes, we found that the environmental justice issue had already occurred in Shenzhen especially for the non-elderly: under the walk mode, nearly 80% of the non-elderly only shared 20% of UGS whilst approximately 80% of the elderly shared 30% of UGS. However, taxi or private vehicles can effectively alleviate the aforementioned phenomenon by reducing the Gini index to less than 0.5. The proposed model is expected to advance the understanding of UGS accessibility and facilitate effective planning to reduce environmental justice.     

Isolation of arbuscular mycorrhizal fungi and Azotobacter chroococcum from local litchi orchards and evaluation of their activity in the air-layers system

Soil samples were collected from rhizosphere of litchi-growing areas of North-Western Himalayan Region (NWHR) of India, for finding qualitative and quantitative differences in arbuscular mycorrhizal (AM) fungi and Azotobacter chroococcum. These samples were taken from plants being grown in different cultivation types namely, weed control with weedicides or tillage; orchard floor either clear or with cover crops; intercropping with cereals and legumes. Qualitative and quantitative differences were noticed with different cultivation types and a marked reduction in the AM fungi was observed in orchards where chemicals were used for weed control and intensive farming system was used on the orchard floor. AM fungi were generally abundant in the soils with range pH 5.5–6.6. Among different AM fungi retrieved from the soils, Glomus spp. was most dominant. Fifteen AM fungal species were isolated, identified and characterized and along with their ability to colonize the roots. In the soil samples, a marked variation in viable bacterial count of A. chroococcum was also noticed due to varied physico-chemical characteristics of the orchard soils. The changes in AM fungal species composition can be attributed to changes in soil chemical properties resulting from cultural practices such as ploughing, application of chemical fertilizers and weedicides. An experiment was also conducted to study the comparative efficacy of four dominant and frequently occurring indigenous AM species namely, Glomus fasciculatum (Thaxter sensu Gerdemann), G. magnicaulis (Hall), G. mosseae (Nicol. & Gerd.), Gigaspora heterogamma (Nicol. & Gerd.) and two A. chroococcum strains viz., AZ₁ and AZ₂ singly and in dual combination to evaluate their effect in air-layers system. Dual inoculation of G. fasciculatum and AZ₁ increased total root length of air-layered shoots by 81.39% over uninoculated control. These studies indicated that indigenously isolated AM fungal species and A. chroococcum strains can be used for air-layering for better adaptation under specific agro-climatic and ecological zone conditions.     

In vitro propagation of some olive (Olea europaea sativa L.) cultivars with different root-ability,and medium development using analytical data from developing shoots and embryos

Short- and long-term objectives for research on tissue culture of the olive are described. Sterile shoots were obtained from single-node woody explants or buds of 3 olive cultivars (‘Frantoio’, ‘Dolce Agogia’ and ‘Moraiolo’) with different root-ability, collected from shoots having different degrees of juvenility (suckers, vigorous nonfruit-bearing and fruit-bearing shoots, which are easy, medium and difficult to root, respectively).Because many of the media tested did not give a satisfactory growth rate and good quality shoots, a new medium was formulated by comparing data from analysis of the main mineral elements found in the apical shoots (4–5 mm long) and in mature embryos in olive and almond. Olive tissues were characterized by a high content of Ca, Mg, S, Cu and Zn compared to almond, which is easy to propagate on MS medium. In this newly derived medium, characterized by a high content of these elements, multiplication rate (number of nodes formed per explant) was about 9× in 40 days. The shoots grew more rapidly and were more tender than when grown in other media. Washing of the explants in water or GSH (reduced glutathione) solution, before sub-culturing, improved quality and growth rate of the shoots.Explants, with 2 or 3 nodes, rooted easily in half-strength MS, in Bourgin and Nitsch, or in half Knop macro and Heller microelements, agar media, with 1 mg 1^?1 NAA and 2% sucrose. Rooting was not affected by the different degrees of juvenility of the original explants used.Hardening-off was achieved by growing plants in a 1:1 mixture of perlite and peat-moss in a transparent plastic chamber with saturated circulating air for 1 month. GA₃ sprayed on the leaves was found to be beneficial in stimulating growth resumption of plantlets.     

Examining the product and process of scenic beauty evaluations using moment-to-moment data and GIS: The case of Savannah,GA

Growing out of a recent debate on aesthetics, and in particular scenic beauty, we added the term ‘process’ to our conceptualization of scenic beauty so it is broader and more dynamic than other traditional definitions. The purpose of this study is to evaluate the product (content of the environment such as tree characteristics) and process (spatial and temporal patterns of change perceived such as frequency, maximum, minimum, and average quality) of scenic beauty tourist evaluations to better understand what and how it is experienced in real-time. Five city street corridors in Savannah, GA, were video recorded with a roadside view during the spring, summer, and winter (2008–2009). Visitors (N = 130) were asked to evaluate the scenic beauty of a video by turning a hand-held dial (Perceptual Analyzer) and completing a questionnaire. Moment-to-moment data, post-video evaluations, and GIS tree data were used to develop a scenic beauty map, evaluation timelines for each season, and a model predicting willingness-to-pay for a trolley tour. The specific tourism product-based characteristics of the urban forest (tree groupings, height, diameter or DBH, age, condition, and species) that contribute to scenic beauty support what is reported in the literature, thus further validating the mapping of real-time data. Both quality (i.e., average scenic beauty) and quantity (i.e., positive changes in scenic beauty per minute) related measures were both significant process-based predictors of tourists’ willingness-to-pay for scenic beauty. The only product-based variable that was significant was an overall measure of quantity of visitor experiences (i.e., eventful measure). The quality of scenic beauty may be only part of the story.     

Growth, survival, and root system morphology of deeply planted Corylus colurna 7 years after transplanting and the effects of root collar excavation

Urban trees are frequently planted with their root collars and structural roots buried well below soil grade, either because of planting practices, nursery production practices, or both. These deeply planted structural roots can impair tree establishment and are thought to reduce tree growth, lifespan, and stability, although research has provided few and contradictory results on these questions to date. This study examines container-grown (55 L) Turkish hazel trees (Corylus colurna L.), planted either at grade, 15 cm below grade, or 30 cm below grade into a well-drained silt loam soil, over nearly 8 years. Five years after planting, in 2004, remediation treatments (root collar excavations) were performed on two replicates of each below-ground treatment. Subsequently, all trees were subjected to flooding stress by being irrigated to soil saturation for approximately 6 weeks. In 2006, flooding stress was repeated. Trees root systems were partially excavated in 2007, and root architecture was characterized. Deep planting did not affect trunk diameter growth over 8 years. Survival was 100% for the first 5 years; however, one 30 cm below grade tree died after flooding in 2004 and another died after the 2006 flooding. Photosynthesis was monitored during the 2004 flooding and all trees experienced decline in photosynthetic rates. There was an apparent slight delay in the decline for trees with excavated root collars and those planted at grade. Girdling roots reduced trunk taper and occurred primarily on unremediated trees planted 30 cm below grade.

Selected individual roots were excavated and followed from the root ball and were observed to gradually rise to the upper soil regions. Analysis of roots emerging from excavation trench faces indicated that vertical root distribution at approximately 1.25 m from the tree trunks was the same regardless of planting depth. Longterm consequences of planting below grade are discussed.     

Application of a dynamic model using agronomic and economic data to evaluate the sustainability of the olive grove landscape of Estepa (Andalusia,Spain)

Context

In the Andalusia region (Spain), olive grove agro-systems cover a wide area, forming social-ecological landscapes. Recent socioeconomic changes have increased the vulnerability of these landscapes, resulting in the abandonment and intensification of farms. The provision of the main ecosystem services of these landscapes have thus been degraded.

Objectives

To analyse the sustainability of an olive grove social-ecological landscape in Andalusia. Specifically, to develop a quantitative model proposing land planning and management scenarios, considering abandonment, production and economic benefits of olive crops in different conditions of erosion and management.

Methods

We applied a dynamic model using agronomic and economic data, to evaluate different types of olive management. We considered different levels of erosion, the loss of production related to this erosion, and useful life spans for each type of management. We simulated scenarios for the long-term assessment of dynamics of crops, abandonment rate, production and benefits.

Results

(a) There was a loss of productive lands and benefits in the medium term in the more intensive crops. (b) Scenarios that partially incorporated ecological management proved to be more sustainable without economic subsidies. (c) The spatial combination of integrated, intensive and ecological plots was sustainable, and was well balanced from an economic, productive and ecological point of view.

Conclusions

Scenarios that partially incorporate ecological management allowed the best economic and environmental balance. However, to ensure the sustainability of olive landscapes, farmers should be financially rewarded for their role in the conservation of ecosystem services through landscape stewardship and direct environmental payments.

     

Diversity,relationships, and genetic fingerprinting of the Listada de Gandía eggplant landrace using genomic SSRs and EST-SSRs

Listada de Gandía is one of the most renowned Spanish eggplant (Solanum melongena L.) landraces. Assessing its genetic diversity and relationships, as well as devising tools for its identification, is of great relevance for the enhancement and protection of this landrace. Forty-two eggplant accessions, which included 25 Striped accessions, of which 19 were of the Listada type (six accessions of Listada de Gandía, eight of Other Spanish Listada, and five of Non-Spanish Listada) and six of the Other Non-Spanish Striped group, and 17 Non-Striped accessions were characterized with 17 genomic SSRs and 32 EST-SSRs. Genomic SSRs had, as a mean, a greater polymorphism and polymorphic information content (PIC) than EST-SSRs. Although Listada de Gandía proved to be genetically diverse, specific and universal alleles for two SSR markers were found for this landrace. All the Listada accessions cluster together in the multivariate PCoA and UPGMA phenograms performed, and are separated from the Other Non-Spanish Striped and Non-Striped accessions. Also, Listada de Gandía accessions were clearly differentiated from the Other Spanish Listada and Non-Spanish Listada accessions in these analyses. SSR markers revealed of great utility to obtain a specific fingerprint for the Listada de Gandía eggplant as well as to establish the uniqueness and distinctness of this landrace. This information will be very helpful for the enhancement and protection from imitation of Listada de Gandía, and contributes to support its potential recognition with a Protected Designation of Origin (PDO) status.     

Effect of the culture environment on stomatal features, epidermal cells and water loss of micropropagated Annona glabra L. plants

Shoots of Annona glabra L. were rooted in vitro under three levels of irradiance and two closure systems (conventional and natural ventilation) of the culture vessels. Once the shoots had been rooted, we studied how the manipulation of the culture environment affects the stomata features and water loss through leaf tissues after the plants are removed from the vessel. The stomata frequency increased significantly in the leaves of plants grown under high (300 μmol m⁻² s⁻¹) compared to low (50 μmol m⁻² s⁻¹) or intermediate (150 μmol m⁻² s⁻¹) irradiance, with higher effect under natural ventilation. Irrespective of the culture environment, leaves developed in vitro attained a higher stomata frequency than those grown in vivo. Under high irradiance and natural ventilation, the leaves presented functional stomata of characteristically elliptical shape and the epidermal cells were smaller and had slightly sinuous anticlinal walls. Besides, water loss through leaves of plants grown under high irradiance and natural ventilation was drastically reduced if these plants were exposed to an environment with low relative humidity thereafter. Our results indicate that an increased light availability and the use of natural ventilation improve the regulatory capacity of water loss in micropropagated A. glabra L. plants and can favor the plants’ survival and growth after transference to the natural environment.     

Effect of tea-polyphenols on the activation of NF-κB and the expression of TGF-β1 mRNA in THP-1 cells incubated with VLDL,LDL or ox-LDL

AIM:To investigate the effect of tea-polyphenols (TP) on the activation of NF-κB and the expression of TGF-β₁ mRNA in THP-1 cells (a human acute monocytic leukemia cell line). METHODS:THP-1 cells were incubated with the different concentrations of TP, VLDL, LDL or ox-LDL. In the THP-1 cellls, the nuclear malposition rate of NF-κB was detected with immunohistochemistry technique, the positive index of the TGF-β₁ mRNA expression was detected by hybridization in situ, and accumulation of total cholesterol (TC) in cells incubated with 0.4-40 μg/L TP was determined with oxidase assay. RESULTS:The nuclear malposition rate of NF-κB, the positive index of the TGF-β₁ mRNA expression and TC in THP-1 cells incubated with 0.4-40 μg/L of TP were lower than those with 0 μg/L of TP in TP-V group, TP-L group and TP-O (P＜0.05). The differences of these markers in THP-1 cells incubated with more than 40 μg/L TP in TP-V group, TP-L group and TP-O were not statistically significant, compared with TP-C group (P＞0.05). CONCLUSION:TP inhibited the activation of NF-κB, the expression of TGF-β₁ mRNA and the foam cell formation in the mono-macrophage.     

Genetic transformation of Citrus sinensis cv. Hamlin with hrpN gene from Erwinia amylovora and evaluation of the transgenic lines for resistance to citrus canker

Transgenic Citrus sinensis (L.) Osb. cv. Hamlin plants expressing the hrpN gene were obtained by Agrobacterium tumefaciens (Smith and Towns) Conn-mediated transformation. hrpN encodes a harpin protein, which elicits the hypersensitive response and systemic acquired resistance in plants. The gene construct consisted of gst1, a pathogen-inducible promoter, a signal peptide for protein secretion to the apoplast, the selection genes nptII or aacC1 and the Nos terminator. The function of gst1 in citrus was evaluated in transgenic C. sinensis cv. Valencia harboring the reporter gene uidA (gus) driven by this promoter. Histochemical analysis for gus revealed that gst1 is activated in citrus leaves by both wounding and inoculation with Xanthomonas axonopodis Starr and Garces pv. citri (Hasse) Vauterin et al. Genetic transformation was confirmed by Southern blot hybridization in eight cv. Hamlin acclimatized plants. RT-PCR confirmed hrpN gene expression in seven cv. Hamlin transgenic lines before pathogen inoculation. Some hrpN transgenic lines showed severe leaf curling and abnormal growth. Six hrpN transgenic lines were propagated and evaluated for susceptibility to X. axonopodis pv. citri. RT-PCR confirmed gene expression in all six hrpN transgenic lines after pathogen inoculation. Several of the hrpN transgenic lines showed reduction in susceptibility to citrus canker as compared with non-transgenic plants. One hrpN transgenic line exhibited normal vegetative development and displayed very high resistance to the pathogen, estimated as up to 79% reduction in disease severity. This is the first report of genetic transformation of citrus using a pathogen-inducible promoter and the hrpN gene. Further evaluations of the transgenic plants under field conditions are planned. Nevertheless, the evidence to date suggests that the hrpN gene reduces the susceptibility of citrus plants to the canker disease.     

Relationship between polymorphism of angiotensin I converting enzyme gene insertion/deletion and ACE,PAI-1 activity in patients with myocardial infarction

AIM:To explore the relationship between polymorphism of angiotensin I converting enzyme gene insertion/deletion (I/D) and ACE, PAI-1 activity in patients with myocardial infarction (MI). METHODS:Ninety-three patients with MI and eighty-seven healthy controls were tested. ACE genomic DNA was amplified using the polymerase chain reaction (PCR). Serum ACE activity was measured by colorimetry, plasma level of PAI-1 activity was determined by spectrophotometric assay. RESULTS:① The frequency of ACE DD genotype and D alleles (32.3% and 54.3%) in MI group was significantly higher than those in control group (12.6% and 37.4%, P<0.01, respectively). ② The ACE activity in serum (216.00±58.26)U/L and plasma PAI-1 activity (0.85±0.19)AU/mL in MI group were significantly higher than those in control group (170.19±48.99)U/L, (0.66±0.20)AU/mL, P<0.01, respectively. The serum ACE activity was positively correlated with plasma PAI-1 activity both in MI group and control group (r=0.7108 and r=0.7829;P<0.01, respectively). ③ In MI group, the serum ACE activity and plasma PAI-1 activity showed a significantly higher level in subjects with DD genotype (251.64±57.76)U/L, (0.96±0.16)AU/mL than those with ID (211.47±51.87)U/L, (0.82±0.18) AU/mL and Ⅱ genotypes (179.84±52.65)U/L, (0.71±0.17)AU/mL. The serum ACE activity and plasma PAI-1 activity were significantly higher in subjects with ID genotype than those with II genotype (P<0.05). In control group, the serum ACE activity and plasma PAI-1 activity showed a significantly higher level in subjects with DD genotype (195.53±54.76)U/L, (0.78±0.20)AU/mL than the subjects with Ⅱ genotype (154.98±52.74)U/L, (0.59±0.17)AU/mL (P<0.05). CONCLUSION:The increased ACE activity caused by DD polymorphism may play an important role in elevating the level of plasma PAI-1. The DD genotype of ACE is associated with high PAI-1 level. The genetic variation of ACE contributes to the balance of fibrinolytic pathway, indicating the pathogenesis mechanisms linking to the ACE I/D genotype and MI.     

Detection of the IgE in cat allergic patients and analysis of the allergic reaction cause during the hyposensitization with IPC-1/IPC-2

AIM:To analyse the cause of allergic reaction during the treatment with synthetic peptide allergen IPC-1/IPC-2 (ALLERVAX CAT).METHODS:The measurement of allergen-specific IgE(as-IgE)level be fore and after the inject ion of IPC-1/IPC-2 and placebo in 27 cats allergic patients.Detection of the as-IgG,as-IgG4,as-IgE,T-IgE and histamine for one supernormal allergic person.RESULTS: No statistically significance were found in IgE in both IPC-1/IPC-2 and placebo groups. There were some obvious changes in the histamine, IgG and IgG₄ levels, and not in IgE for this supernormal patient. CONCLUSION: IPC-1/IPC-2 has no effect on the IgE. Hypernormal reaction is not related to IgE during the hyposensitization. It may be related to the IgG, especially to the IgG₄ which induce the histamine release that is non-IgE-dependent.     

Dissemination of Phytophthora cactorum, cause of crown rot in strawberry,in open and closed soilless growing systems and the potential for control using slow sand filtration

Closed (recirculating) growing systems provide a greater potential for the dispersal of water-borne plant pathogens and disease expression compared to open (run-to-waste) systems. Here we studied the effects of three soilless growing systems (open, closed, and closed with slow sand filtration) on the dispersion of Phytophthora cactorum propagules and the severity of the crown rot disease in strawberry (Fragaria × ananassa Duch.). The plant-growth medium used was coir fiber. The three growing systems showed the same density of P. cactorum propagules in the water drained from the growing media. However, propagules of this pathogen were not detected by the baits in the filtered solution recovered from slow sand filtration. In all systems Phytophthora propagules dispersed from the inoculated plant to adjacent uninoculated plants. At the end of the first crop no differences in the severity of crown rot were found between the different systems of crop culture. However, at the end of the second crop cycle, crown rot in the closed soilless system without slow sand filtration was more severe than in the other two systems. These results demonstrated that the commercial potential of slow sand filtration to prevent propagule dispersal and hence suppress crown rot in strawberry crops grown in a closed culture system.     

Curcumin inhibits lipid peroxidation and the expression of TGF-β1 and PDGF in the liver of rats with hepatic fibrosis

AIM: To investigate changes of the level of reactive oxygen species (ROS),malondialdehyde (MDA),transforming growth factor-β1 (TGF-β1) and platelet-derived growth factor (PDGF) expression in a rat hepatic fibrosis model and the effect of curcumin ,and discuss the mechanism of the prophylactic effect of curcumin on hepa tic fibrosis.METHODS: Rat models of hepatic fibrosis were established by intraperitoneally injection of carbon tetrachloride.Curcumin of 20 mg,10 mg,5mg per 100 gram weight of rat was given to these rats respectively at the same time.Normal,fibrosis model and positive groups were made as controls.After eight weeks,all rats were executed and the blood and liver were kept.Serum level of ROS was tested by chromatometry.Content of MDA in liver homogenate was tested by thiobarbituric acid (TBA) method.Expressions of TGF-β1 and PDGF in liver were detected by immunohistochemical method. RESULTS: Serum level of ROS in fibrotic group increased significantly compared with that of normal group,and which was depressed obviously in curcumin groups(P＜0.05).Content of MDA in liver of curcumin group reduced significantly compared with that of fibrotic group (P＜0.01).Expressions of TGF-β1 and PDGF in fibrotic group increased significantly compared with those of normal group,which were depressed obviously in curcumin groups (P＜0.01).CONCLUSION: Curcumin could inhibit expression of TGF-β1,PDGF and lipid peroxidation in liver.These may be mechanisms of curcumin preventing hepatic fibrosis.