Data collection and advanced statistical analysis in phytotoxic activity of aerial parts exudates of Salvia spp

In order to define the phytotoxic potential of Salvia species a database was developed for fast and efficient data collection in screening studies of the inhibitory activity of Salvia exudates on the germination of Papaver rhoeas L. and Avena sativa L.. The structure of the database is associated with the use of algorithms for calculating the usual germination indices reported in the literature, plus the newly defined indices (Weighted Average Damage, Differential Weighted Average Damage, Germination Weighted Average Velocity) and other variables usually recorded in experiments of phytotoxicity (LC50, LC90). Furthermore, other algorithms were designed to calculate the one-way ANOVA followed by Duncan's multiple range test to highlight automatically significant differences between the species. The database model was designed in order to be suitable also for the development of further analysis based on the artificial neural network approach, using Self-Organising Maps (SOM).

Antioxidant activity of Punica granatum fruits.

Arils, juice and rinds of Punica granatum fruits and their aqueous and ethyl acetate extracts displayed good antioxidant activity.

myo-[3H]-inositol loaded erythrocytes and white ghosts: two models to investigate the phosphatidylinositol synthesis in human red cells.

Human erythrocytes were loaded with myo-[(3)H]-inositol in the presence or absence of cytidine trisphosphate to investigate the synthesis of membrane phosphoinositides in the intact red cell. The addition of cytidylic nucleotides to the loading mixture yielded a four-fold increase in the [(3)H]-labeling of the membranes. The [(3)H]-labeling of phosphatidylinositol, phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate was distinguished by two chromatographic techniques. Experiments performed on white ghosts demonstrated the presence of CDP-diacylglycerol synthase and phosphatidylinositol synthase. These results and those already reported allow to discuss a possible turnover of the inositol polar head.

Effects of UV-C irradiation on phosphoinositide turnover in plant cells: similarities with those occurring via the formation of reactive oxygen intermediates in animal cells.

With the aim of examining the response of plant cells to UV-C irradiation, we investigated the behaviour of the phosphatidylinositol 4,5 bisphosphate (PtdIns 4,5-P2) molecule (the precursor of the phosphoinositide signal transduction cascade) by exposing callus cells from Peucedanum verticillare to UV-C (130 J m-2) and by examining the level and the fatty acid composition of PtdIns 4,5-P2 at different times after irradiation. We show that a pathway for the UV-C response includes transient PtdIns 4,5-P2 breakdown. The effect of ultraviolet rays is mimicked by H2O2 suggesting that in this plant it may be brought about by reactive oxygen intermediates (ROI), as already underlined in experimental animal models.

Inositol 1,4,5-trisphosphate distribution in Lycopersicon esculentum Mill seedlings cultivated "in vitro" under different conditions.

Measurements of inositol 1,4,5-trisphosphate (Ins1,4,5-P3) in cotyledons, epicotyls and roots of tomato seedlings grown "in vitro" either in the light or in the dark indicated that higher concentrations of this signal-transducing molecule are contained in hypogeous vs. epigeous tissues. The same was observed in induced cotyledon explants grown in the light in the presence of growth regulators. Data concerning phosphatidylinositol metabolism in seedling roots are also reported. Taken together, our results may be helpful in understanding the role of the polyphosphoinositide signal system in plants.