Drought resistance in pearl millet

The influence of wilting on the levels of free proline, soluble proteins, reducing sugars, starch and on the activities of nitrate reductase, invertase, amylase and pyrophosphatases have been studied in the leaf tissue of five cultivars of pearl millet at their vegetative stage under pot culture conditions. The metabolic changes could not be correlated with the yield behaviour of the cultivars under a drought condition in the field.     

Towards the mechanism of altered nutrients uptake in renal brush border membrane vesicles from pyelonephritic rats

Affinity constant (Km) of D-glucose, L-alanine, L-aspartate, L-lysine, L-proline and nutrients coupled Na+ were determined in renal brush border membrane vesicles prepared from control and pyelonephritic rats. The Km of D-glucose, amino acids and nutrients coupled Na+ was noted to be significantly increased (p less than 0.001) in experimental animals. The Vmax of D-glucose and amino acids was determined at different concentrations of nutrients keeping extravesicular Na+ constant or at different concentrations of extravesicular Na+ keeping nutrient concentration constant. In the experimental rats the Vmax decreased significantly (p less than 0.01) when compared to control. The increased Km and decreased Vmax may be one of the underlying mechanism leading to decrease in the uptake of D-glucose and amino acids.     

Omega-3 fatty acids increase the arachidonic acid content of liver cholesterol ester and plasma triacylglycerol fractions in the rat.

Recent studies have demonstrated that dietary fish oils rich in eicosapentaenoic acid (C20:5,omega 3) lower the content of arachidonic acid and its metabolites in plasma and tissue phospholipids. The present study examined the fatty acid composition of cholesterol ester and triacylglycerol fractions from plasma and livers of rats fed diets enriched with saturated fatty acids (beef tallow), alpha-linolenic acid (linseed oil) or eicosapentaenoic acid (fish oil). Feeding diets containing linseed oil or fish oil for 28 days increased arachidonic acid (C20:4,omega 6) levels in the cholesterol ester fraction of liver and in the triacylglycerol fraction of the plasma lipids. Plasma cholesterol esters were depleted of C20:4,omega 6 after feeding of the diet containing either linseed oil or fish oil. The changes in C20:4,omega 6 content cannot be explained by alterations in cholesterol ester or triacylglycerol pools of plasma and liver. These results suggest that the decrease in phospholipid C20:4,omega 6 content generally observed after fish oil consumption may be partly due to a shift of C20:4,omega 6 from phospholipid to the triacylglycerol and/or cholesterol ester pools in the same tissue. Triacylglycerols and cholesterol esters may therefore play a buffering role in the homeostatic maintenance of tissue phospholipid levels of arachidonic acid.     

Induced Mutation inPetunia nyctaginiflora JUSS.

Seeds ofPetunia nyctaginifloraJuss. a common ornamental garden plant, were treated with two alkylating agents (methyl methane sulphonate and N-methyl-N’-nitro-N-nitrosoguanidine). Six morphological and seven chlorophyll mutants were isolated from M₂ segregating families. The isolated induced mutants are described and genetically analysed.     

Evidence for critical-period programming of intestinal transport function: variations in the dietary ratio of polyunsaturated to saturated fatty acids alters ontogeny of the rat intestine

2-week isocaloric modifications in the dietary ratio of polyunsaturated/saturated fatty acids (P/S) alters intestinal transport in rats. This study was undertaken to test the hypotheses that (1) the fatty acid composition of a nutritionally adequate diet in early life has lasting consequences for active and passive intestinal transport processes; and (2) early life feeding experiences with diets of varying fatty acid composition influence the intestines' ability to adaptively up- or down-regulate intestinal transport in later life. Female Sprague-Dawley rats were weaned onto S or P and were maintained on these diets for 2, 10 or 12 weeks. An in vitro uptake technique was used in which the bulk phase was vigorously stirred to reduce the effective resistance of the intestinal unstirred water layer. P decreased and S increased the uptake of glucose, and this effect was progressive from 2 to 12 weeks. Switching from a P to an S diet decreased jejunal but increased ileal uptake of glucose, whereas switching from an S to a P diet was associated with a decline in both the jejunal and the ileal uptake of glucose. The ileal uptake of galactose increased as the animals grew on either P or S. Switching from P to S resulted in a decline in ileal uptake of galactose, whereas the opposite effect was observed when switching from S to P. The effect of feeding P or S on hexose uptake was influenced by the animals' dietary history: ileal glucose and galactose uptake was lower in animals fed P at an early age (PSP) than in animals fed P for the first time in later life (SSP). Jejunal glucose and galactose uptake was also lower in animals fed S at an early age (SPS) than in those fed S for the first time in later life (PPS). The alterations in the uptake of long-chain saturated and unsaturated fatty acids and cholesterol did not progress with longer periods of feeding, and in the jejunum, lipid uptake did not change when switching from P to S or S to P. Early feeding with P (PSP vs. SSP) was associated with lower jejunal uptake of 18:3 and lower ileal uptake of 12:0, whereas previous feeding with S (SPS vs. PPS) was associated with lower ileal uptake of cholesterol. The changes in uptake of hexoses and lipids was not explained by differences in the animals' food consumption, body or intestinal weight or mucosal surface area.(ABSTRACT TRUNCATED AT 400 WORDS)     

Use of Brassica callus culture to induce sporulation in Alternaria brassicae (Berk.) Sacc.

A non-sporulating isolate of Alternaria brassicae, inoculated on callus culture of Brassica juncea cv. Kranti, colonized the callus and produced spores. When captafol, a fungicide, was added (100 mg/l) to the callus culture medium, if effectively checked fungal contamination and saprophytic growth of A. brassicae on culture medium, without adversely affecting callus growth or establishment of dual culture.     

A spectrophotometric method for calmodulin assay

The activity of calmodulin as an activator of cAMP phosphodiesterase was assayed. AMP was hydrolyzed by 5'-nucleotidase, and the adenosine formed was measured by both liquid scintillation counting and spectrophotometry at 265 nm. Calmodulin activities measured by the two methods were equivalent, indicating that spectrophotometric assay of calmodulin can be used in place of the isotopic method.