Anticonvulsant potential of holy basil, Ocimum sanctum Linn., and its cultures

Callus cultures from stem of O. sanctum were induced on slightly modified Murashige and Skoog's (MS) medium and supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D, 1-2 ppm) and kinetin (kn, 1 ppm). Different extractives of stem, leaf and stem callus of O. sanctum were tested for anticonvulsant activity against standard drug phenytoin using maximal electroshock (MES) model. Ethanol and chloroform extractives of stem, leaf and stem calli were effective in preventing tonic convulsions induced by transcorneal electroshock.     

Ascorbic acid status of mullet, Mugil cephalus Linn., exposed to cadmium

The effects of acute and chronic cadmium exposures on ascorbic acid concentrations and cadmium accumulation in the tissues of juvenile mullet, Mugil cephalus , are described. Hepatic ascorbic acid reserves were maintained in untreated mullet fed a diet containing ascorbate, but decreased 60% in individuals exposed to 10 mg Cd 1^-1 for six weeks. Ascorbic acid depletion was accompanied by a massive accumulation of cadmium in the liver. Similar changes were found in gill tissue. In contrast, ascorbic acid concentrations were largely unaffected in kidney tissue which had a limited capacity to accumulate the metal. There were marked fluctuations of ascorbic acid levels in the brain. Only small amounts of cadmium were accumulated by this tissue. These results indicate that in mullet liver, gill and brain ascorbic acid stores may be depleted during chronic cadmium poisoning.     

Somatic embryogenesis in Jatropha curcas Linn., an important biofuel plant

Jatropha curcas L. is one potential source of non-edible biofuel-producing energy crop. Its importance also lies in its medicinal properties. The species is primarily propagated through heterozygous seeds, and thus the seed oil content varies from 4 to 40%. Moreover, due to its perennial nature, seed setting requires 2 to 3 years time. The seed viability and rate of germination are low, and quality seed screening is another laborious task; thus, seed propagation alone cannot provide quality planting material for sustainable use. Somatic embryogenesis, a powerful tool of plant biotechnology for faster and quality plant production has been successfully applied to regenerate plants in Jatropha curcas for the first time. Embryogenic calli were obtained from leaf explants on MS basal medium supplemented with only 9.3 μM Kn. Induction of globular somatic embryos from 58% of the cultures was achieved on MS medium with different concentrations of 2.3–4.6 μM Kn and 0.5–4.9 μM IBA; 2.3 μM Kn and 1.0 μM IBA proved to be the most effective combination for somatic embryo induction in Jatropha curcas. Addition of 13.6 μM adenine sulphate stimulated the process of development of somatic embryos. Mature somatic embryos were converted to plantlets on half strength MS basal medium with 90% survival rate in the field condition. The whole process required 12–16 weeks of culture for completion of all steps of plant regeneration. This protocol of somatic embryogenesis in Jatropha curcas may be an ideal system for future transgenic research.     

禾穗新缬草,中国败酱科归化植物新记录种

报道了发现于江苏省的败酱科(Valerianaceae)新缬草属(Valerianella Mill.)归化植物新记录种:禾穗新缬草[V.locusta(Linn.)Laterr.]。     

Histochemical studies in stomatal apparatus of Phaseolus mungo Linn, Lathyrus sativus Linn and Opuntia elatior Mill

With histochemical methods the distribution of some enzymes and metabolic substances in the epidermal peelings of Phaseolus mungo, Lathyrus sativus, and Opuntia elatior under light and dark conditions is examined. Dehydrogenases oxidases, transferases and hydrolases were studied. Fluctuations in the activity of hydrolases, especially, acid phosphatase, lipase, glucose-6-phosphatase, adenosine triphosphatase, dehydrogenases and transferases were observed during light and dark conditions. The role of such fluctuations in relation to stomatal regulation is discussed. Based on the present studies the following is suggested; stomatal opening and closing is related to structural and metabolic changes, and these changes are brought about by sugar gradients in the guard cells; light is enhancing the synthesis of sugars and some hormones, and besides this it stimulates membrane bound adenyl cyclase and release of cyclic AMP which affects the permeability; subsidiary cells actively participate in the stomatal physiology. Lysosomal hydrolytic enzymes like acid phosphatase are actively involved in catabolic phase of normal guard cells metabolism and regulate the osmotic pressure of the guard cells.