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101.
102.
Physiologic and yield effects of mixtalol at various concentrations sprayed on rape at the anthesis stage were examined. Foliar sprays of 4 and 2 ppm mixtalol significantly increased the chlorophyll content of rape leaves and pods, reduced the accumulation of malondialdehyde and ethylene production, and delayed the degradation of superoxide dismutase and catalase activities of the rape plant. Mixtalol also increased root oxidizability. Meanwhile, the number of branches and pods per plant was increased, and a 10.7% and 8.2% increase of seed yield over the controls was observed with treatments of 4 and 2 ppm mixtalol, respectively. No significant effects from mixtalol were observed on the maturation of plants or on the seed oil content or the erucic acid and glucosinolate content. Total rape oil production increased with 4 and 2 ppm mixtalol significantly by 12.4% and 10.5%, respectively, over the controls.Abbreviations MTL
mixtalol
- MDA
malondialdehyde
- TBA
thiobarbituric acid
- SOD
Superoxide dismutase
- CAT
catalase
- TTC
tetrazolium 相似文献
103.
104.
The dissociation constants for the binding of ferric enterobactin with FepA and FecA are quantitated with displacement experiments. It is found that K
d for FepA is 12 times lower than the one for FecA. This indicates that FepA is an high-affinity receptor while FecA binds ferric enterobactin with a lower affinity. Monoclonal antibodies specific for binding epitopes of FepA inhibit the binding of ferric enterobactin with purified FepA. These same antibodies do not inhibit the binding of ferric enterobactin with purified FecA. This indicates that the binding epitopes in FecA and FepA are different. 相似文献
105.
106.
107.
108.
The protection of F1 ATPase by inorganic phosphate, ADP, ATP, and magnesium ion against inactivation by 1-fluoro-2,4-dinitrobenzene, 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole, and 1-(ethoxycarbonyl)-2-ethoxy-1,2-dihydroquinoline, respectively, has been investigated. Dissociation equilibrium constants and rate constants for the labeling reactions have been deduced from a quantitative treatment of the kinetic data. Comparison of these dissociation constants with each other and with the corresponding literature values indicates that the essential Tyr, Arg, Lys, and Glu or Asp residues are indeed located at the catalytic site of the enzyme. Examination of the rate constants for the labeling reactions in the presence of excess inorganic phosphate, ADP, ATP, or magnesium ion, respectively, suggests that the essential phenol and amino groups are located nearer to the bound inorganic phosphate or the gamma-phosphate group than to the alpha- or beta-phosphate group of the bound ATP, that the essential guanidinium group is located nearer to the alpha- or beta-phosphate group than to the gamma-phosphate group of the bound ATP or the bound inorganic phosphate, and that the essential carboxylate group is located slightly farther away but complexed with magnesium ion which it shares with the bound inorganic phosphate. A mechanism consistent with these topographical relationships is proposed for the catalytic hydrolysis and synthesis of ATP. 相似文献
109.
Strong, adult (Type II) autologous mixed lymphocyte reactions (AMLR) were observed in cultures of lymphoid cells from both A.TH and A.TL mice. These were suppressed by more than 90% in the continuous presence of 7.5 × 10?8M hydrocortisone-21-sodium succinate. This concentration of hormone had minimal effects on the allogeneic mixed lymphocyte response (MLR) and the mitogenic response to concanavalin A (Con A). Higher concentrations suppressed all three responses. Treatment of autologous cell mixtures for the first 30 hr with 7.5 × 10?8M hydrocortisone resulted in a 78% suppression of the AMLR. This was not associated with a detectable decrease in the quantity of Ia antigens on the stimulator-cell surface, as evaluated by the susceptibility of treated cells to antibody dependent, complement-mediated lysis, using [A.TH × B.10M]F1 anti-A.TL antiserum. Hence, this suppression did not appear to result from an alteration of the antigens putatively associated with stimulation of the AMLR. Separate pretreatment of stimulator and responder cells with 7.5 × 10?8M hydrocortisone followed by culturing with appropriate companion cells had no major effect on the AMLR. Therefore, low-dose hydrocortisone did not appear to selectively eliminate or permanently inactivate subpopulations of responder or stimulator cells. Rather, it appeared to regulate active cellular processes that are initiated by the coculturing of these cells and are required for the early stages of autologous lymphocyte activation. 相似文献
110.
Irwin P. Ting 《Photosynthesis research》1981,2(1):39-48
Water stress induces Crassulacean acid metabolism (CAM) in Portulacaria afra as manifested by day stomatal closure, organic acid fluctuation, and night CO2 uptake. We now have evidence that abscisic acid treatment of leaves causes partial stomatal closure that is accompanied by the induction of CAM in a manner similar to water stress. There appears to be an inverse relationship between exogenous CO2 uptake and decarboxylation of organic acids in that organic acids remain high during the day providing stomata are open. When stomata close, there is consumption of organic acids by decarboxylation. The hypothesis is that stomatal opening controls CAM in this species.This material is based upon work supported by the Science and Education Administration of the USDA under Competitive Grant No. 5901-0410-8-0018-0. 相似文献