Regional responses in antioxidant system to exercise training and dietary Vitamin e in aging rat brain

We have evaluated the effect of exercise, Vitamin E and a combination of both on the antioxidant enzymes (AOEs) - superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) along with the products of lipid peroxidation (LP) - malondialdehyde (MDA) and lipofuscin-like auto fluorescent substances (LF-like AFS) in discrete brain regions of rats of 4 (young adults), 8 (old adults), 12 (middle-age) and 22 months (mos) old of age. Hippocampus (HC) showed greater increase in GSH-Px activity than cerebral cortex (CC) to exercise and Vitamin E and was irrespective of the age. A combination of both was effective in the CC of all age groups but not in the supplemented sedentary of 12- and 22-mo-olds. CAT activity increased significantly in the HC of supplemented and trained rats but not in the combination group of any age. SOD increased in both the regions of supplemented trainees. However, old were more benefited in terms of maximal elevation in the HC. Vitamin E reduced MDA content in both regions of adult. LF-like AFS decreased significantly in supplemented sedentary and trainees of all ages. Our results demonstrate that an age-related deficit in AOEs in the CC and HC can be overcome through Vitamin E plus exercise, and further suggests the rationale for looking at these markers of oxidative stress in several age-related neuronal diseases. © 2003 Elsevier Inc. All rights reserved

Transpiration and leaf growth of potato clones in response to soil water deficit

Potato (Solanum tuberosum ssp. Tuberosum) crop is particularly susceptible to water deficit because of its small and shallow root system. The fraction of transpirable soil water (FTSW) approach has been widely used in the evaluation of plant responses to water deficit in different crops. The FTSW 34 threshold (when stomatal closure starts) is a trait of particular interest because it is an indicator of tolerance to water deficit. The FTSW threshold for decline in transpiration and leaf growth was evaluated in a drying soil to identify potato clones tolerant to water deficit. Two greenhouse experiments were carried out in pots, with three advanced clones and the cultivar Asterix. The FTSW, transpiration and leaf growth were measured on a daily basis, during the period of soil drying. FTSW was an efficient method to separate potato clones with regard to their response to water deficit. The advancedclones SMINIA 02106-11 and SMINIA 00017-6 are more tolerant to soil water deficit than the cultivar Asterix, and the clone SMINIA 793101-3 is more tolerant only under high solar radiation

Transpiration response of de-rooted peanut plants to aquaporin inhibitors

Selected genotypes of peanut (Arachis hypogaea L.) have been identified that show constrained transpiration rates (TR) at high atmospheric vapor pressure deficits (VPD) in contrast to genotypes that exhibit continually increasing TR with increasing VPD. The constraint of TR has been proposed as a putative trait for soil water conservation and improved crop performance during late-season water deficits. In soybean (Glycine max (L.) Merr.), limited TR at high VPD has been found to be related to a decreased hydraulic conductance in leaves. A different population of water-transport-mediating proteins, i.e., aquaporins (AQP), was indicated in soybean by measuring the response of shoot TR to treatment with a silver AQP inhibitor. The objective of this study was to test the shoots of four peanut genotypes for a transpiration response when treated with four inhibitors of AQP, which appear to have differing modes of action in inhibiting AQP. Transpiration rate of all four genotypes were equally sensitive to exposure to cycloheximide and mercuric chloride (HgCl 2). Treatment of the shoots of three genotypes (ICGS 44, TMV 2 and ICGV 86699) with silver nitrate (AgNO 3) and hydrogen tetrachloroaurate (HAuCl 4) resulted in decreased TR while treatment of genotype ICGV 91284, which had constrained TR at high VPD, resulted in little or no decrease of TR. In fact, the AgNO 3 treatment of this fourth genotype resulted in a stimulation of TR at higher AgNO 3 concentrations. Among the three genotypes with TR not constrained at high VPD, two genotypes had less decrease in TR with HAuCl 4 treatment than the third genotype. These results identified major differences in shoot response to AQP inhibitors, which were hypothesized to indicate different populations of AQP in the leaves of these peanut genotypes. © 2012 Elsevier B.V