Raising the pH of the Pulsing Solution Improved the Acropetal Transport of NAA and 2,4-D and Their Efficacy in Reducing Floret Bud Abscission of Red Cestrum Cut Flowers.

The use of auxins to improve the vase life of cut flowers is very limited. Previous studies demonstrated that a pulse treatment of Red Cestrum (Cestrum elegans Schlecht.) cut flowers with 2,4-dichlorophenoxyacetic acid (2,4-D) significantly reduced floret bud abscission, whereas 1-naphthaleneacetic acid (NAA) was ineffective. This difference resulted, at least in part, from the higher acropetal transport capability of 2,4-D compared to that of NAA. The present research focused on examining the factors affecting the acropetal transport, and hence the efficacy of the two auxins in reducing floret bud abscission of Red Cestrum cut flowers. We assumed that the differential acropetal transport capability of the two auxins results from the difference in their dissociation constants (pKa), with values of 2.75 and 4.23 for 2,4-D and NAA, respectively, which affects their pH-dependent physicochemical properties. Thus, increasing the pH of the pulsing solution above the pKa of both auxins might improve their acropetal movement. Indeed, the results of the present research show that raising the pH of the pulsing solution to pH 7.0 and above improved the efficacy of the two auxins in reducing floret bud abscission, with a higher effect on 2,4-D than that on NAA. Raising the pH of the pulsing solution decreased the adsorption and/or uptake of the two auxins by the cells adjacent to the xylem vessels, leading to an increase in their acropetal transport. The high pH of the pulsing solution increased the dissociation and hence decreased the lipophilicity of the auxin molecules, leading to improved acropetal movement. This effect was corroborated by the significant reduction in their 1-octanol/water partition coefficient (K OW ) values with the increase in the pH. A significant increase in the CeIAA1 transcript level was obtained in response to 2,4-D pulsing at pH 7.0 and 8.25 and to NAA pulsing at pH 8.25, indicating that the acropetally transported auxins were taken up by the cells under these conditions. Our data suggest that raising the pH of the pulsing solution would significantly contribute to the increased efficacy of auxins in improving the vase life of cut flowers.

Integration of motor imagery and physical practice in group treatment applied to subjects with Parkinson's disease.

BACKGROUND AND PURPOSE: The application of motor imagery practice in the treatment of Parkinson's disease (PD) is a novel treatment approach for improving motor function. The purpose of this study was to compare group treatment using a combination of physical and motor imagery practice with group treatment using only physical practice in subjects with PD. METHODS: Of 23 patients with idiopathic PD, 12 received combined therapy, whereas 11 received physical therapy alone. Exercises for both groups were applied during 1-h sessions held twice a week for 12 weeks. Comparable motor tasks provided to both groups included callisthenic exercises, functional tasks, and relaxation exercises. However, the experimental group was treated with both imagery and real practice, whereas the control group received only physical exercises. Outcome measures included the time required to complete sequences of movements, the performance of balance tasks, impairment and functional scores on the Unified Parkinson's Disease Rating Scale (UPDRS), and specific cognitive abilities (Stroop and clock drawing tests). RESULTS: Following the intervention, the combined treatment group exhibited significantly faster performance of movement sequences than the control group. In addition, the experimental subjects demonstrated higher gains in the mental and motor subsets of the UPDRS and in the cognitive tests. Both groups improved on the activities of daily living scale. CONCLUSIONS: The combination of motor imagery and real practice may be effective in the treatment of PD, especially for reducing bradykinesia. The implementation of this treatment regimen allows for the extension of practice time with negligible risk and low cost.

In vitro sugar uptake by grapefruit (Citrus paradisi) juice-sac cells.

To further our understanding of the mechanisms of sugar uptake and accumulation into grapefruit (Citrus paradisi Macf. cv. Marsh seedless), the patterns of uptake and utilisation of sucrose, glucose and fructose by Citrus juice cells was investigated. Analyses were conducted on sliced juice sacs that were incubated in radioactive [14C]-sugar solutions with unlabelled sugars, in the presence or absence of metabolic inhibitors. Both hexoses demonstrated an initial uptake peak in December and a second uptake peak in February-March. From March through April the rates of sucrose uptake increased to levels comparable to those of glucose and fructose. Sucrose and its moieties fructose and glucose entered the juice cells of Citrus juice fruit by an insaturable, and mostly by an independent, process. However, NaN3 and carbonylcyanide m-chlorophenylhydrazone (CCCP) produced slight inhibition of these processes. Cells took up hexoses at a greater rate than sucrose, with accumulation reaching a plateau by 4-8 h, and then continuing unabated, in the case of glucose, for 42 h. Uptake of all three sugars increased linearly in the range of sugar concentrations tested, which extended from 0.01 to 320 mm, denoting an insaturable system for sugar uptake. 14CO2 evolution was relatively low in all the experiments, the lowest evolution being recorded when the uptake of [14C]-sucrose was studied, while the highest 14CO2 evolution was recorded when the uptake of [14C]-glucose was studied. The data demonstrate a preferential utilisation of glucose over fructose and sucrose. In all the experiments, the two metabolic inhibitors significantly inhibited the decarboxylation of the three sugars.