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101.
102.
Expression of an ABA-induced gene of tomato in transgenic tobacco during periods of water deficit 总被引:9,自引:1,他引:8
The gene le25 is an abscisic acid (ABA)-induced gene of tomatowhich is expressed both in wilted vegetative organs and developingseeds. Spatial and temporal expression was analysed in tobaccoplants transformed with a chimeric gene in which 5'-upstreamDNA sequences of le25 were fused to the E. coli uidA gene, whichencodes ß-glucuronidase (GUS). Histochemical stainingrevealed that GUS was expressed in all tissues of vegetativeorgans in response to water deficit. Exogenous ABA induced expressionto a lesser extent, even though ABA content was the same asdroughtstressed leaves, indicating a difference in responseto endogenous ABA compared to exogenous ABA. Water-deficit-inducedGUS expression in floral tissues was examined in pre-anthesisfloral buds from four different stages (IIV; 11, 16,33, 49 mm bud length, respectively). While non-stressed floralorgans showed no GUS activity except in pollen at stages IIIand IV, GUS activity was water-deficit-induced in sepals ofall stages, petals of stage II, and stigmas of stage II andIII. In seeds, GUS activity was detected in both the embryoand endosperm at 15 d post-anthesis, which coincided with alarge increase in the concentration of ABA in the seed. In transgenicplants, the le25 5'-flanking DNA drove expression of GUS duringwater deficit in two modes: non-tissue-specific expression invegetative organs, and tissue-specific expression in reproductiveorgans. The location of GUS activity indicated that ABA concentrationis elevated throughout the tissues of the leaf during periodsof water deficit. Key words: Tomato, ABA, drought stress, lea gene, water deficit 相似文献
103.
104.
OBJECTIVE: To test the efficacy of a graded aerobic exercise programme in the chronic fatigue syndrome. DESIGN: Randomised controlled trial with control treatment crossover after the first follow up examination. SETTING: Chronic fatigue clinic in a general hospital department of psychiatry. SUBJECTS: 66 patients with the chronic fatigue syndrome who had neither a psychiatric disorder nor appreciable sleep disturbance. INTERVENTIONS: Random allocation to 12 weeks of either graded aerobic exercise or flexibility exercises and relaxation therapy. Patients who completed the flexibility programme were invited to cross over to the exercise programme afterwards. MAIN OUTCOME MEASURE: The self rated clinical global impression change score, "very much better" or "much better" being considered as clinically important. RESULTS: Four patients receiving exercise and three receiving flexibility treatment dropped out before completion. 15 of 29 patients rated themselves as better after completing exercise treatment compared with eight of 30 patients who completed flexibility treatment. Analysis by intention to treat gave similar results (17/33 v 9/33 patients better). Fatigue, functional capacity, and fitness were significantly better after exercise than after flexibility treatment. 12 of 22 patients who crossed over to exercise after flexibility treatment rated themselves as better after completing exercise treatment 32 of 47 patients rated themselves as better three months after completing supervised exercise treatment 35 of 47 patients rated themselves as better one year after completing supervised exercise treatment. CONCLUSION: These findings support the use of appropriately prescribed graded aerobic exercise in the management of patients with the chronic fatigue syndrome. 相似文献
105.
106.
Post-thawing survival of ram sperm was examined after semen which had been layered on top of isolation columns containing solutions of bovine serum albumin (BSA) in Tris diluent was processed for freezing by the pellet method. Sperm isolated from the bottom of the BSA column had better post-thawing survival than sperm from the top of the column. The efficiency of sperm isolation was affected by the concentration of BSA in the column, the holding time of semen on the column and the concentration of sperm in the layered semen. The best post-thawing survival of sperm occurred when semen diluted to a concentration of 200 x 10(6) sperm/ml was layered on a column of 6% BSA in Tris diluent and the bottom layer of the column was isolated for freezing after two hours' holding time. 相似文献
107.
alpha, alpha'-Bis[3-(N,N-diethylcarbamoyl)piperidino]-p-xylene enhances human blood platelet membrane integrity by exerting a stabilizing action at the level of the dense tubular system in surface membrane complexes known to sequester platelet calcium. 相似文献
108.
Production of an insulin-like growth factor by osteosarcoma 总被引:3,自引:0,他引:3
J Blatt C White S Dienes H Friedman T P Foley 《Biochemical and biophysical research communications》1984,123(1):373-376
To test the possibility that osteosarcoma cells produce their own growth factors, we measured levels of insulin and somatomedin C (SMC), an insulin-like growth factor, in culture media of two cell lines derived from patients with that disease. SMC but not insulin levels increased three- to ten-fold over a period of 7 days paralleling the increases in cell number. Production of SMC was inhibited by cycloheximide. 相似文献
109.
Production of Viscous Dextran-Containing Whey-Sucrose Broths by Leuconostoc mesenteroides ATCC 14935 下载免费PDF全文
Viscous broths were produced by growing Leuconostoc mesenteroides on a medium containing whey supplemented with sucrose. When combined with similarly produced xanthan-containing broths, a synergistic increase in viscosity was observed. 相似文献
110.
Douglas L. Vizard R.Allen White Allen T. Ansevin 《Archives of biochemistry and biophysics》1984,229(2):498-508
High-resolution thermal denaturation was used to measure the heterogeneity within repeated DNA sequences. An analysis of combined denaturation/redenaturation experiments on mouse satellite DNA suggests the existence of two minor components, one of which does not appear in the prepared EcoRII monomer. The resolving power of the denaturation/redenaturation experiment is estimated and contrasted with that of the reassociation experiment, often used to estimate repeated sequence heterogeneity. A mathematical model of the redenaturation experiment was developed and applied to mouse satellite data; the results suggest that only one-fourth of the mismatched base pairs are energetically significant in the reduction of heteroduplex stability. 相似文献