Transformation of tobacco with an Arabidopsis thaliana gene involved in trehalose biosynthesis increases tolerance to several abiotic stresses

Summary Trehalose (a non-reducing disaccharide) plays an important role in abiotic stress protection. It has been shown that using trehalose synthesis genes of bacterial origin, drought and salt tolerance could be achieved in several plants. A cassette harboring the AtTPS1 gene under the control of the CaMV35S promoter and the Bialaphos resistance gene was inserted in the binary plasmid vector pGreen0229 and used for Agrobacterium-mediated transformation of tobacco (Nicotiana tabacum). T0 plants obtained were analyzed by PCR for the presence of AtTPS1 gene. Thirty lines were positive and seeds were germinated on media with 6 mg/l PPT to obtain T1 plants that were grown in the greenhouse to obtain T2 seeds that were germinated on selective media. Lines which seeds showed a 100 % survival rate were considered homozygous transgenic T1 lines. Three lines were selected and gene expression confirmed by northern and western blots. Transgenic seeds were germinated on media with different concentrations of mannitol (0, 0.25, 0.5 and 0.75 M) and sodium chloride (0, 0.07, 0.14, 0.2, 0.27 and 0.34 M) to score their tolerance to osmotic stress. Assays were conducted to test the tolerance of transgenic plants to drought (measurement of water percentage as a consequence of water withdrawal), desiccation (measurement of water loss as a consequence leaf detaching) and temperature stresses (germination at 15 ^∘C and 35^∘C). Transgenic tobacco plant lines registered higher germination rates under osmotic and temperature stress situations than did wild-type plants. Responses to drought and desiccation stresses were similar for all plant lines. It can hence be suggested that the heterologous expression of TPS1 gene from Arabidopsis can be used successfully to increase abiotic stress tolerance in model plants and probably in other crops.     

温度对大叶桃花心木(Swietenia macrophylla King)幼苗叶片的光合影响(英文)

本文研究了大叶桃花心木(Swietenia macrophylla King)一年生幼苗在经过夜温处理后的光响应曲线和在饱和光强下的CO2反应曲线。结果表明:在大气CO2浓度下,叶片的最佳光合作用温度在25-31℃之间,而在饱和CO2浓度下为31-35℃。在25℃以下光合速率开始降低,主要是由于羧化效率的降低,而当温度超过31℃时,光合速率下降,是因为羧化效率的降低和呼吸速率的增加。CO2浓度对光合的促进作用在低温下受到抑制,这意味着未来在CO2浓度增高的情况下,高浓度的CO2对热带常绿植物光合的促进在冬天低温情况下表现不十分明显。图4参23。     

Autoregressive spatial analysis and individual tree modeling as strategies for the management of <Emphasis Type="Italic">Eremanthus erythropappus</Emphasis>

The objectives of this study were to apply statistical techniques to discriminate fertilization treatments of Eremanthus erythropappus (DC.) MacLeish. through autoregressive modeling, and to develop individual tree models for diameter and crown area (CA) projection to define management strategies for candeia plantations subjected to different fertilization treatments. This is an important tree species originating from the Brazilian Atlantic Rain forest and Savannah biomes, intensively used in the cosmetic industry. Nonetheless, to date, research has not addressed the management of natural stands or plantations of the species. Our experiment was located in Baependi, Minas Gerais, Brazil, and comprised of four randomized blocks and 13 treatments. The treatments consisted of 12 different regimes of fertilization plus a control. Each sample plot was composed of 50 plants plus two border plants in a planting spacing of 2.5 × 2.0 m and undergoing pruning at 5 and 6 years of age. Starting in the second year, total tree height (H) and circumference (at 1.30 m from the ground or breast height, CBH) were measured every 6 months. Starting in the fifth year CA was measured. Tree growth varied by fertilization strategy. Differences were detected by using an autoregressive approach, considering that standard statistical methods were not powerful enough to detect significant differences. Three growth groups were formed, and maximum growth was obtained for treatment 10 (NPK, 8-28-16). Management guidelines are provided based on individual tree models for different fertilization levels.     

Biological activity of some Patagonian plants

Citotoxicity (inhibition of cell division in fertilized eggs of Loxechinus albus) and general toxicity (using embryos of Artemia salina) of plants belonging to the genera Senecio, Deschampsia, Alstroemeria, Anarthrophyllum, Chloraea and Geranium were investigated.     

Growth and yield of coffee plants in agroforestry and monoculture systems in Minas Gerais, Brazil

This research compared coffee plants (Coffea arabica L.) grown in an agroforestry and monoculture systems. Data were collected during two years, on vegetative growth, reproductive development, nutritional status and yield of coffee, besides monitoring air temperature and the tree growth. All trees in agroforestry system increased in growth, resulting in a reduction in the magnitude of the diurnal temperature variation and also maximum temperature. Coffee plants in agroforestry system had less branch growth and leaf production, more persistent and larger leaves, and presented earlier flowering, with a smaller number of productive nodes and flower buds, leading to smaller berry yield than plants in monoculture system. In both systems, the coffee plants showed adequate leaf nutrient levels, except for P and K. The yield of 2443 kg ha^-1 of coffee from the monoculture was greater than 515 kg ha^-1 of coffee from the agroforestry system.     

Analysis of fatty acids in Longissimus muscle of steers of different genetic breeds finished in pasture systems

The chemical composition, the fatty acids profile, and conjugated linoleic acids content in Longissimus muscle (LM) of steers have been determined. For such, 18 steers (6, Nellore, NEL) and their Simmental (6, NSI), and Santa Gertrudes (6, NSG) crossbreds finished in pasture system with Brachiaria brizantha cv. marandu for about 3 months with approximate weight at slaughter of 480 kg at average age approximate of 25 months. The lipid content increased in the following order influenced by genetic groups: Nellore, F1 Nellore × Simmental and F1 Nellore × Santa Gertrudes crossbreds. The lipid content increased while moisture, ash and protein contents decreased. The content of saturated fatty acids (SFA) was affected by genetic groups. The conjugated linoleic acids contents (CLA) in fat were similar in the genetic groups, but the quantity of CLA concentrations in muscle lipids of steers with larger total lipid was higher. The predominant CLA was CLA cis-9, trans-11.     

Antitumor effects of deracoxib treatment in 26 dogs with transitional cell carcinoma of the urinary bladder

OBJECTIVE-To evaluate the antitumor activity and toxic effects of deracoxib, a selective cyclooxygenase-2 inhibitor, in dogs with transitional cell carcinoma (TCC) of the urinary bladder. DESIGN-Clinical trial. Animals-26 client-owned dogs with naturally occurring, histologically confirmed, measurableTCC of the urinary bladder. PROCEDURES-Dogs were treated PO with deracoxib at a dosage of 3 mg/kg/d (1.36 mg/lb/d) as a single-agent treatment for TCC. Tumor response was assessed via radiography, abdominal ultrasonography, and ultrasonographic mapping of urinary bladder masses. Toxic effects of deracoxib administration in dogs were assessed through clinical observations and hematologic and biochemical analyses. RESULTS-Of 24 dogs for which tumor response was assessed, 4 (17%) had partial remission, 17 (71%) had stable disease, and 3 (13%) had progressive disease; initial response could not be assessed in 2 of 26 dogs. The median survival time was 323 days. Median time to progressive disease was 133 days. Renal, hepatic, and gastrointestinal abnormalities attributed to deracoxib administration were noted in 4% (1/26), 4% (1/26), and 19% (5/26) of dogs, respectively. CONCLUSIONS AND CLINICAL RELEVANCE-Results indicated that deracoxib was generally well tolerated by dogs and had antitumor activity against TCC.     

Host associated polymorphisms in the Corynebacterium pseudotuberculosis rpoB gene sequence

Corynebacterium pseudotuberculosis is a widespread facultative intracellular pathogen that causes caseous lymphadenitis disease in sheep and goats, and generates cutaneous abscesses and granulomas in horses and cattle. Although some genes have been studied for diagnostic and phylogenetic analysis within the genus Corynebacterium, at subspecies level the pathogen has been poorly analyzed. The aim of this study was to characterize C. pseudotuberculosis strains isolated from domestic animals, through the sequencing of a hypervariable rpoB gene segment. As result, there were identified host associated rpoB polymorphisms in strains infecting sheep, goats and horses from Chile. These differences suggest the existence of bacterial genotypes, in which the nucleotide similarity values were ranging from 98.8 to 99.8%. In conclusion, the analysis of polymorphisms in the partial rpoB sequence can be used as a diagnostic tool that differentiates C. pseudotuberculosis strains at subspecies level.     

Frequency of blood type A, B, and AB in 515 domestic shorthair cats from the Lisbon area

Background: The A, B, and AB feline blood types are recognized worldwide and their frequencies vary geographically and among breeds. Frequencies of feline blood types have been reported previously from northern Portugal; however, they are unknown in other parts of the country. Objectives: This 13‐year retrospective study was undertaken to determine the frequency of feline blood types in domestic shorthair (DSH) cats from the Lisbon area of central Portugal. Methods: Blood samples were obtained at the Veterinary Teaching Hospital of the Technical University of Lisbon and its Veterinary Blood Bank and at several veterinary clinics in the Lisbon area. Blood‐typing was performed by the classical agglutination assay or using a cartridge assay. Results: The study population comprised 515 DSH cats of both sexes and various ages. Frequencies of blood types A, B, and AB were 97.5%, 2.1%, and 0.4%, respectively. Conclusion: As in other parts of the world, this study showed a clear predominance of type‐A cats in the Lisbon area of Portugal.