Kinetics of L-valine uptake in tobacco leaf discs. Comparison of wild-type, the digenic mutant Val(r)-2, and its monogenic derivatives

Moringa oleifera: a food plant with multiple medicinal uses

Moringa oleifera Lam (Moringaceae) is a highly valued plant, distributed in many countries of the tropics and subtropics. It has an impressive range of medicinal uses with high nutritional value. Different parts of this plant contain a profile of important minerals, and are a good source of protein, vitamins, beta-carotene, amino acids and various phenolics. The Moringa plant provides a rich and rare combination of zeatin, quercetin, beta-sitosterol, caffeoylquinic acid and kaempferol. In addition to its compelling water purifying powers and high nutritional value, M. oleifera is very important for its medicinal value. Various parts of this plant such as the leaves, roots, seed, bark, fruit, flowers and immature pods act as cardiac and circulatory stimulants, possess antitumor, antipyretic, antiepileptic, antiinflammatory, antiulcer, antispasmodic, diuretic, antihypertensive, cholesterol lowering, antioxidant, antidiabetic, hepatoprotective, antibacterial and antifungal activities, and are being employed for the treatment of different ailments in the indigenous system of medicine, particularly in South Asia. This review focuses on the detailed phytochemical composition, medicinal uses, along with pharmacological properties of different parts of this multipurpose tree.

Removal of cadmium from aqueous system by shelled Moringa oleifera Lam. seed powder

The present study explores the unexploited sorption properties of the plant Moringa oleifera Lam. for decontamination of Cd at laboratory scale. Sorption studies using standard practices were carried out in batch experiments as functions of biomass dosage, contact time, metal concentrations, particle size and pH. Percentage sorption in each case was computed on the basis of Cd estimation using a planar NaI (TI) detector coupled to a 4K MCA (Canberra Accuspec Card with PC-AT 386). The adsorption data accurately in a Freundlich isotherm. Sorption studies resulted in the standardization of optimum conditions for removal of Cd (85.10%) as follows: biomass dosage (4.0 g), metal concentration (25 microg/ml), contact time (40 min) and volume of the test solution (200 ml) at pH 6.5. Fourier transform infrared (FTIR) spectrometry highlighted amino acid-Cd interactions responsible for sorption phenomenon. The findings open up new avenues in the removal of toxic metals by shelled Moringa oleifera seeds (SMOS) from water bodies as low cost, domestic and environmentally friendly safe technology.

Sucrose transport into plasma membrane vesicles from tobacco leaves by H+ symport or counter exchange does not display a linear component

Uptake of [14C]sucrose by plasma membrane vesicles from leaves of tobacco (Nicotiana tabacum L.) was measured after the imposition of an inwardly directed proton gradient (delta pH = 2) and an electrical gradient (delta psi = -68 mV, inside negative) across the vesicle membrane. The vesicles were isolated from a microsomal fraction by two-phase partitioning using media that contained 330 mM of either sorbitol or sucrose. Sucrose transport into vesicles isolated using the sorbitol-containing media showed the hallmarks of electrogenic H+-symport, as it was highly dependent on delta pH, could be increased three- to four-fold by delta psi, and was abolished by carbonylcyanide m-chlorophenylhydrazone (CCCP). Transport of [14C]sucrose into vesicles that were isolated using the sucrose-containing media apparently occurred by counter exchange. Its initial influx also depended on a low external pH, but it was insensitive to CCCP and hardly stimulated by delta psi. Both symport and counter exchange obeyed simple Michaelis-Menten kinetics. Transport that depends linearly on the external sucrose concentration could not be detected, indicating that the 'linear' component that has been observed in sucrose uptake by leaf tissues does not represent a transport route that is provided by the sucrose symporter. The potential role of H+/sucrose-symporters in phloem unloading is briefly discussed.

Amino acid transporters are localized to transfer cells of developing pea seeds

To determine the nature and cellular localization of amino acid transport in pea seeds, two cDNA clones belonging to the AAP family of H(+)/amino acid co-transporters (PsAAP1 and PsAAP2) were isolated from a cotyledon cDNA library of pea (Pisum sativum L.). Functional expression in the yeast amino acid uptake mutants 22Delta6AAL and 22Delta8AA showed that PsAAP1 mediates transport of neutral, acidic, and basic amino acids. RNA-blot analyses showed that PsAAP1 is expressed in seeds and vegetative organs, including amino acid sinks and sources, whereas PsAAP2 could not be detected. For developing seeds, transcripts of PsAAP1 were detected in coats and cotyledons, with seed coats giving a weak signal. In cotyledons, expression was highest in epidermal-transfer-cell-enriched tissue. RNA in situ hybridization analysis showed that PsAAP1 was predominantly present in epidermal transfer cells forming the outer surface of cotyledons, which abuts the seed coats. Overall, our observations suggest that this transporter, which is localized in transfer cells of cotyledons, might play a role in the uptake of the full spectrum of amino acids released from seed coats.