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851.
Effect of dietary supplementation of different oils during the first or second half of pregnancy on the glucose tolerance of the sow 总被引:1,自引:0,他引:1
Corson AM Laws J Litten JC Dodds PF Lean IJ Clarke L 《Animal : an international journal of animal bioscience》2008,2(7):1045-1054
Poor glucose tolerance may be an under-researched contributory factor in the high (10% to 20%) pre-weaning mortality rate observed in pigs. Insulin resistance commences at around week 12 of gestation in the sow, although there are conflicting reports in the literature about the extent to which insulin resistance is modulated by maternal diet. The aim of the study was to determine the effects of supplementing the maternal diet with different dietary oils during either the first half or the second half of gestation on the glucose tolerance of the sow. Sows were offered the control (C: n = 5) diet as pellets or the C diet plus 10% extra energy (n = 16 per group) derived from either: (i) extra pellets; (ii) palm oil; (iii) olive oil; (iv) sunflower oil; or (v) fish oil. Experimental diets were fed during either the first (G1) or second (G2) half of gestation. A glucose tolerance test (GTT) was conducted on day 108 of gestation by administering 0.5 g/kg glucose i.v. Blood samples were taken every 5 to 10 min for 90 min post administration. The change in body weight and backfat thickness during gestation was similar but both type and timing of dietary supplementation influenced litter size and weight. With the exception of the sunflower oil group, supplementing the maternal diet in G1 resulted in larger and heavier litters, particularly in mothers offered palm oil. Basal blood glucose concentrations tended to be more elevated in G1 than G2 groups, whilst plasma insulin concentrations were similar. Following a GTT, the adjusted area under the curve was greater in G1 compared to G2 sows, despite no differences in glucose clearance. Maternal diet appeared to influence the relationship between glucose curve characteristics following a GTT and litter outcome. In conclusion, the degree of insulin sensitivity can be altered by both the period during which maternal nutritional supplementation is offered and the fatty acid profile of the diet. 相似文献
852.
Teppei Moriwaki Yujirou Yamamoto Takehiko Aida Tatsuya Funahashi Toshiyuki Shishido Masataka Asada Shamusul Haque Prodhan Atsushi Komamine Tsuyoshi Motohashi 《Plant biotechnology reports》2008,2(1):41-46
Salinity stress is a major limiting factor in cereal productivity. Many studies report improvements in salt tolerance using
model plants, such as Arabidopsis thaliana or standard varieties of rice, e.g., the japonica rice cultivar Nipponbare. However, there are few reports on the enhancement
of salt tolerance in local rice cultivars. In this work, we used the indica rice (Oryza sativa) cultivar BR5, which is a local cultivar in Bangladesh. To improve salt tolerance in BR5, we introduced the Escherichia coli catalase gene, katE. We integrated the katE gene into BR5 plants using an Agrobacterium tumefaciens-mediated method. The introduced katE gene was actively expressed in the transgenic BR5 rice plants, and catalase activity in T1 and T2 transgenic rice was approximately 150% higher than in nontransgenic plants. Under NaCl stress conditions, the transgenic
rice plants exhibited high tolerance compared with nontransgenic rice plants. T2 transgenic plants survived in a 200 mM NaCl solution for 2 weeks, whereas nontransgenic plants were scorched after 4 days
soaking in the same NaCl solution. Our results indicate that the katE gene can confer salt tolerance to BR5 rice plants. Enhancement of salt tolerance in a local rice cultivar, such as BR5, will
provide a powerful and useful tool for overcoming food shortage problems. 相似文献
853.
Okochi M Kanie K Kurimoto M Yohda M Honda H 《Applied microbiology and biotechnology》2008,79(3):443-449
Prefoldin is a jellyfish-shaped hexameric chaperone that captures a protein-folding intermediate and transfers it to the group II chaperonin for correct folding. In this work, we characterized the organic solvent tolerance of Escherichia coli cells that overexpress prefoldin and group II chaperonin from a hyperthermophilic archeaum, Pyrococcus horikoshii OT3. The colony-forming efficiency of E. coli cells overexpressing prefoldin increased by 1,000-fold and decreased the accumulation of intracellular organic solvent. The effect was impaired by deletions of the region responsible for the chaperone function of prefoldin. Therefore, we concluded that prefoldin endows E. coli cells by preventing accumulation of intracellular organic solvent through its molecular chaperone activity. 相似文献
854.
Wild-type tobacco plants (Nicotiana tabacum L. cv. Petit Havanna line SR1) and plants transformed with full-length alfalfa ferritin cDNA with the chloroplast transit peptide under the control of a Rubisco small subunit gene promoter (C3 and C8) were cold-treated at 0 degrees C with continuous light (250mumolm(-2)s(-1)). These transgenic plants had higher chlorophyll content and higher F(v)/F(m) chlorophyll-a fluorescence induction parameters than wild-type plants after 2 or 3d of cold treatment in C3 and C8 transgenic plants, respectively. Thermoluminescence studies on the high-temperature bands suggest that these plants suffered less oxidative damage in comparison to the wild-type genotype. The present experiments provide evidence that transgenic tobacco lines overexpressing alfalfa ferritin, which is accumulated in the chloroplasts, may show higher tolerance to various stress factors, generating ROS including low temperature-induced photoinhibition. 相似文献
855.
856.
This study investigated the role of quercitol in osmotic adjustment in field-grown Eucalyptus astringens Maiden subject to seasonal drought stress over the course of 1 year. The trees grew in a native woodland and a farm plantation in the semi-arid wheatbelt region of south Western Australia. Plantation trees allocated relatively more biomass to leaves than woodland trees, but they suffered greater drought stress over summer, as indicated by lower water potentials, CO2 assimilation rates and stomatal conductances. In contrast, woodland trees had relatively fewer leaves and suffered less drought stress. Plantation trees under drought stress engaged in osmotic adjustment, but woodland trees did not. Quercitol made a significant contribution to osmotic adjustment in drought-stressed trees (25% of total solutes), and substantially more quercitol was measured in the leaves of plantation trees (5% dry matter) than in the leaves of woodland trees (2% dry matter). We found no evidence that quercitol was used as a carbon storage compound while starch reserves were depleted under drought stress. Differences in stomatal conductance, biomass allocation and quercitol production clearly indicate that E. astringens is both morphologically and physiologically 'plastic' in response to growth environment, and that osmotic adjustment is only one part of a complex strategy employed by this species to tolerate drought. 相似文献
857.
Three types of transgenic tobacco plants were acquired by separate transformation or co-transformation of a vacuolar Na+/H+ antiporter gene, SeNHX1, and a betaine synthesis gene, BADH. When exposed to 200 mM NaCl, the dual gene-transformed plants displayed greater accumulation of betaine and Na+ than their wild-type counterparts. Photosynthetic rate and photosystem II activity in the transgenic plants were less affected
by salt stress than wild-type plants. Transgenic plants exhibited a greater increase in osmotic pressure than wild-type plants
when exposed to NaCl. More importantly, the dual gene transformed plants accumulated higher biomass than either of the single
transgenic plants under salt stress. Taken together, these findings indicate that simultaneous transformation of BADH and SeNHX1 genes into tobacco plants can enable plants to accumulate betaine and Na+, thus conferring them more tolerance to salinity than either of the single gene transformed plants or wild-type tobacco plants.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
858.
An in vitro plant regeneration system was established from the spores of Pteris vittata and identification of its tolerance, and accumulation of gametophytes and callous, to arsenic (As) and copper (Cu) was investigated. The highest frequency (100%) of callus formation was achieved from gametophyte explants treated with 0.5 mg l?1 6-benzylaminopurine (6-BA) + 0.5 mg l?1 gibberellin acid (GA). Furthermore, sporophytes were differentiated from the callus tissue derived from gametophyte explants on MS medium supplemented with 0.5 mg l?1 6-BA, 0.5–1.0 mg l?1 GA and additional 300 mg l?1 lactalbumin hydrolysate (LH) for 4 weeks. The optimum combination of ½ MS + 1.0 mg l?1 GA + 0.5 mg l?1 6-BA + 300 mg l?1 LH promoted sporophyte formation on 75 ± 10% of the callus. Every callus derived from gametophyte explants could achieve 3–4 sporophytes. The in vitro growth of gametophyte and callus was accelerated in the medium containing Na3AsO4 lower than 0.5 mM, but this growth was inhibited with 2 mM Na3AsO4. And with the increase of Na3AsO4 in the culture medium from 0 to 2 mM, the As accumulation in gametophytes and callus increased and achieved a level of 763.3 and 315.4 mg kg?1, respectively. Gametophytes and calluses transplanted to culture medium, supplemented with different concentrations of CuSO4, are similar to those in Na3AsO4, and the Cu accumulation in gametophytes could achieve 7,940 mg kg?1 when gametophytes were subcultured in medium containing 3 mM CuSO4. These results suggested that the high efficiency propagation system could be a useful and rapid means to identify other heavy metal tolerance and accumulation. Further, the regeneration ability of callus made it possible for genetic transformation of this fern. 相似文献
859.
Ramírez-Benítez JE Chee-González L Hernandez-Sotomayor SM 《Journal of inorganic biochemistry》2008,102(8):1631-1637
The primary Al-tolerance mechanism in plants involves exudation and/or accumulation of specific organic acid species, which form non-phytotoxic complexes with Al3+ under physiological conditions. An evaluation was done of the role of organic acids in the tolerance mechanism of a cell suspension line of coffee Coffea arabica that exhibits Al-tolerance (LAMt) but for which the metabolic tolerance mechanism remains unknown. Significant differences existed in malate dehydrogenase and citrate synthase activities (key enzymes in organic acids metabolism) between protein extracts (day 7 of culture cycle) of the L2 (Al-sensitive) and LAMt (Al-tolerant) cells when cell suspensions were treated with 100 μM AlCl3. HPLC analysis showed that the suspension cells of both lines exudate malate when incubated in a minimal solution but that exudation was not enhanced by treatment with AlCl3 (100 μM). This is the first study demonstrating that plant Al-tolerance may be associated with down-regulation of malate dehydrogenase and citrate synthase activities. 相似文献
860.