A 7S DNA polymerase in the cytoplasmic fraction from higher plant

A 7S DNA polymerase, which resembled high molecular weight human cell DNA polymerase in size, elution behavior from DEAE-cellulose and phosphocellulose columns and some other properties, was demonstrated for the first time in the cytoplasmic fraction of a higher plant (normal and crown gall tumor tissue cultures of tobacco).     

Ultracytochemical localization of estrogen-stimulated guanylate cyclase in rat uterus

Estrogens are known to increase cyclic guanosine monophosphate (cGMP) levels in the uterus of rats by enhancing guanylate cyclase (GC) activity. In the present study, the cytochemical localization of GC activity was studied in the uteri of immature and ovariectomized rats after treatment with diethylstilbestrol (DES), progesterone, estrogen antagonist (CI628), and a combination of DES and CI628. Twenty-four hours after the first dose of DES, moderate to strong guanylate cyclase activity was indicated by lead phosphate precipitate on the luminal microvillar and basolateral surfaces of epithelial cells, whereas strong activity was found on the plasma membranes of fibroblasts, endothelial cells, and myometrial cells. The enzyme activity in the epithelial cells declined slightly 24 hr after the second daily dose of DES. Uterine tissues from DES-treated rats that were preheated at 60 degrees C for 30 min or preincubated with a GC inhibitor showed no reaction product. Guanylate cyclase activity was not observed cytochemically in the uterine tissues of the vehicle control (immature or ovariectomized) or progesterone-and CI628-treated animals. Weak guanylate cyclase activity was observed on the plasma membranes of epithelial cells and endothelial cells after doses of DES and CI628 were given simultaneously. The biochemical assays of the total homogenate in vitro indicated that uterine GC showed about a twofold increase after one dose of DES and a 1.3-fold increase following two doses (one dose per day) of DES when compared with their respective nontreated controls, or with progesterone-treated uteri. GC was found in particulate (09%) and cytosol (10%) fractions.These data demonstrated that DES stimulated uterine guanylate cyclase activity, while progesterone and CI628 were ineffective at the doses used. Estrogen antagonist CI628 doses not completely suppress the effect of DES.     

Changes in enzymic activity during cultivation of human cells in vitro

The composition of chromatin, its template activity and the activity of certain chromatin-associated enzymes, including DNA polymerase (DP) and soluble RNase, DNase, DP and seryl tRNA synthetase, were examined in early and late passage of WI-38 cells and of WI-38VA13 cells.No significant changes in soluble RNase, DNase, seryl tRNA synthetase or soluble and chromatin-associated DP were found with increasing passage of WI-38 cells. The activity of seryl tRNA synthetase and DP in WI38VA13 cells was, however, significantly higher than WI-38 cells in all passages. A decline in RNA synthesizing activity of chromatin, an increase in the proportion of RNA and histone in chromatin, as well as an increase in the activities of ‘chromatin-associated enzymes’ (RNase, DNase, protease, nucleoside triphosphatase, DPN pyrophosphorylase) were noted in WI-38 cells with increasing passages. Although RNA synthesizing activity of chromatin from WI38VA13 cells was lower than that from WI-38 cells, the former also were much lower in ‘chromatin-associated enzymes’. An increase of chromatin-associated enzymes responsible for RNA, DNA and protein degradation in WI-38 cells in successive passages, and a much lower activity of these enzymes in WI-38VA13 cells (which have an indefinite doubling potential in vitro) suggests that an elevation in the activity of these enzymes, which would seriously interfere with the chromatin function, could result in ‘aging’ of WI-38 cells.     

Auriculoside,a new flavan glycoside from Acacia auriculiformis

The structural elucidation of auriculoside, a new flavan glucoside from Acacia auriculiformis, is described. This is the third report of a flavan glycoside unsubstituted in the heterocyclic ring.     

Effect of formulated root endophytic fungus Piriformospora indica and plant growth promoting rhizobacteria fluorescent pseudomonads R62 and R81 on Vigna mungo

In the present investigation, the effect of three beneficial organisms (root endophytic fungus Piriformospora indica (Pi) and pseudomonads strains R62 and R81) and their four different consortia (Pi+R62, Pi+R81, R62+R81, Pi+R62+R81) was investigated on the plant Vigna mungo through their inorganic carrier-based (talcum powder and vermiculite) formulations. All the treatments resulted in significant increase in growth parameters under glasshouse as well as field conditions and showed a consistency in their performance on moving from glasshouse to field conditions. In glasshouse conditions, a maximum increase of 4.5-fold in dry root weight and 3.9-fold in dry shoot weight compared to control was obtained with vermiculite-based consortium formulation of Pi+R81. In field studies using vermiculite as carrier, a maximum enhancement of 3.2-fold in dry root weight, 3.0-fold in dry shoot weight, 8.4-fold in number of nodules and 4.0-fold in number of pods in comparison to control was obtained with the bio-inoculant formulation containing consortium of Pi+R81. The same treatment also caused the highest improvement of 1.9-fold in nitrogen content and 1.7-fold in phosphorus content, while the highest increase of 1.4-fold in potassium content was obtained with Pi alone.