Local signalling pathways regulate the Arabidopsis root developmental response to Mesorhizobium loti inoculation.

Numerous reports have shown that various rhizobia can interact with non-host plant species, improving mineral nutrition and promoting plant growth. To further investigate the effects of such non-host interactions on root development and functions, we inoculated Arabidopsis thaliana with the model nitrogen fixing rhizobacterium Mesorhizobium loti (strain MAFF303099). In vitro, we show that root colonization by M. loti remains epiphytic and that M. loti cells preferentially grow at sites where primary and secondary roots intersect. Besides resulting in an increase in shoot biomass production, colonization leads to transient inhibition of primary root growth, strong promotion of root hair elongation and increased apoplasmic acidification in periphery cells of a sizeable part of the root system. Using auxin mutants, axr1-3 and aux1-100, we show that a plant auxin pathway plays a major role in inhibiting root growth but not in promoting root hair elongation, indicating that root developmental responses involve several distinct pathways. Finally, using a split root device, we demonstrate that root colonization by M. loti, as well as by the bona fide plant growth promoting rhizobacteria Azospirillum brasilense and Pseudomonas, affect root development via local transduction pathways restricted to the colonised regions of the root system.

[Evaluation of the treatment of ovarian infertility in women with moderate hyperprolactinemia]. / Ocena leczenia nieplodnosci jajnikowej u kobiet z mierna hyperprolaktynemia.

The authors evaluated the therapy by means of clomiphene++ and hCG in a group of 34 menstruating women aged 18-41 who suffered from ovarian infertility and hyperprolactinaemia not exceeding 100 ng/ml. Previous treatment of the women by means of bromoergocryptine decreasing the prolactin concentration did not provoked ovulation. It was found that moderate hyperprolactinaemia still blocked ovulation in one third of the women undergoing therapy. In a group of patients with a concentration of PRL from 50 to 100 ng/ml of blood serum there was a lower percentage of ovulation (62% v 67%) and subsequent pregnancies (23% v 33%). The authors did not find hypofunction of corpus luteum in women who reacted to the therapy. The average progesterone concentration amounted to 11.2 +/- 2.6 ng/ml of blood serum. The hormone concentration was significantly lower in a group of women with prolactinaemia exceeding 50 ng/ml (10.4 +/- 2.5 ng/ml vs 12.6 +/- 3.1 t = 1.86, p less than 0.1). The course of subsequent pregnancies in all cases, also in the group of women with prolactinaemia exceeding 50 ng/ml, was favourable.

Effect of exercise on the content of lipids, cholesterol and on the composition of fatty acids in the adrenals of rats receiving rapeseed oil in diet.

The effect of different levels of high-erucic acid rapeseed oil in diet and exposure to graded exercise on the contents of total lipids and total cholesterol, and the composition of fatty acids, in total lipids and cholesterol ester fractions in the adrenals of Wistar rats was investigated. Presence of erucic acid in the diet produced greater changes in the characteristic composition of fatty acids in the fraction of cholesterol esters than in the total lipids in the adrenals. The intensity of changes in the composition of fatty acids was greater with higher amounts of rapeseed oil in the diet and longer administration of the diet. Exercise decreased the changes in fatty acid composition in the fraction of cholesterol esters in rats receiving 50% of calories from rapeseed oil. In the group receiving 30% of calories from rapeseed oil the trained rats accumulated more rapidly cholesterol in the adrenals than the untrained rats. Exercise load had no effect on the total lipid level in the adrenals.

Effect of exercise on the lipid content, lipid fatty acid composition and morphology of myocardial and skeletal muscles in rat.

The effect of exercise on the morphology of the myocardial and skeletal muscle, total lipid content and lipid fatty acid composition was checked in rats fed a rapeseed oil-containing diet. The graded exercise was found to reduce the growth rate of animals. Myocardial fatty degeneration was less intense and erucic acid content lower in trained rats fed a diet with 50% kcal of rapessed oil than the untrained ones. The opposite was true when rapeseed oil supplied 30% of calories. Histiocytic granulomata were more numerous in trained rats. Exercise failed to affect the accumulation of erucic acid in skeletal muscle.