Low phosphate nutrition alters bean plants’ ability to assimilate and translocate nitrate

Bean plants (Phaseolus vulgaris L.) were cultured for 10 or 18 days on phosphate sufficient (+P) or phosphate deficient (‐P) nutrient medium. Nitrate and phosphate distribution between shoot and root, nitrate uptake, and nitrate reductase activity (NR activity, in vivo and in vitro) in root and leaves was estimated. The decrease in Pi concentration in leaves and roots led to decreased rate of NO₃ uptake and increased NO₃ accumulation in roots, accompanied by alterations in NO₃ distribution between shoot and roots. Nitrate reductase activity estimated in vitro was twice higher than estimated in vivo and both in +P and ‐P plants was lower in the roots than in the shoots. The decrease of NR activity in ‐P plants was more pronounced in the roots and after 2 weeks of phosphate starvation it was about 40% lower as compared with the control. The depression in nitrate uptake may be the result of feedback inhibition due to accumulation of nitrate in the roots. The increased NO₃ concentration in root tissue may be explained by decreased NR activity and lower transport of nitrate from roots to shoot.     

Analysis of Noxious Gas Pollution in Horse Stable Air

The aim of this study was to determine quantitative and qualitative occurrence of noxious gas compounds in the stable, depending on the time of the day (4:00 AM, 12:00, 8:00 PM), the height (20 cm, 150 cm), and the place (boxes, aisle) from which the samples were collected. Seven compounds were analyzed (NH₃, SO₂, COS, HCN, CH₄, NO₂, and CO). For analyzing stable air, a mobile gas analyzer was used. The time of day was a significant differential factor (P < .01) for concentrations of NH₃, COS, and CH₄. The highest concentrations of CH₄, COS, NO₂, NH_3, and CO appeared at 4:00. For the rest of the studied compounds (SO₂, HCN, CO) differences were not statistically significant, but there was a tendency for the highest concentrations at 12:00. The concentrations of gas compounds depending on height did not differ significantly from each other, but there was a tendency for higher concentrations of NH₃, SO₂, CH₄, and CO at 150 cm and for HCN at 20 cm. COS and NO₂ remained constant at both heights in boxes. The places where the samples were collected was a significant differential factor (P < .01) for NH₃ and SO₂. For the rest of the studied compounds the differences were not statistically significant. It can be concluded that many noxious compounds may appear without being noticed, and that is why it is necessary to provide stables with efficient air exchange throughout the day.     

Diploid Potato Hybrids as Sources of Resistance to Blackspot Bruising

Resistance to bruising is an important quality trait of potato depending on multiple genetic and environmental factors. Thirty one interspecific diploid hybrids and two tetraploid standards were evaluated for resistance to bruising in 2 years. Diploids originated from crosses between wild and primitive Solanum species and dihaploids of S. tuberosum. Two-year mean values of bruising resistance of tested genotypes indicated significant variability of the trait. Analysis of variance showed significant effects of genotype, year and interaction between them on the trait. Broad-sense heritability of bruising resistance was estimated as moderately high, Hb?=?0.73. Content of L-tyrosine, the main substrate of discoloration reaction, was not significantly correlated with brusing in tested diploid hybrids. The clones, that were resistant to blackspot bruise, also combined quality traits and resistances to many pathogens. All these traits could be transferred together into tetraploid level in 4x?×?2x crosses via male 2n gametes produced by diploid hybrids.     

Effect of Conceptus on Transforming Growth Factor (TGF) β1 mRNA Expression and Protein Concentration in the Porcine Endometrium—In Vivo and In Vitro Studies

Transforming growth factor (TGF) β and its receptors are expressed at the conceptus-maternal interface during early pregnancy in the pig. The present studies were conducted to examine: (1) the effect of conceptus products on TGFβ1 mRNA expression and protein concentration in the porcine endometrium using in vivo and in vitro models, and (2) the effect of TGFβ1 on proliferation of porcine trophoblast cells in vitro. During in vivo experiments, gilts with one surgically detached uterine horn were slaughtered on days 11 or 14 of the estrous cycle and pregnancy. For in vitro studies, endometrial explants and luminal epithelial (LE) cells co-cultured with stromal (ST) cells were treated with conceptus-exposed medium (CEM). Moreover, porcine trophoblast cells were treated with TGFβ1, and the number of viable cells was measured. On day 11, the presence of conceptuses had no effect on TGFβ1 mRNA expression, but decreased the TGFβ1 protein concentration in the connected uterine horn compared with the detached uterine horn. In contrast to day 11, on day 14 after estrus, TGFβ1 mRNA expression and protein content in the endometrium collected from the gravid uterine horn were greater when compared with the contralateral uterine horn. The treatment of endometrial slices with CEM resulted in greater TGFβ1 mRNA expression and protein secretion. LE cells responded to CEM with an increased TGFβ1 mRNA level. Moreover, TGFβ1 stimulated the proliferation of day 14 trophoblast cells. In summary, porcine conceptuses may regulate TGFβ1 synthesis in the endometrium at the time of implantation. TGFβ1, in turn, may promote conceptus development by increasing the proliferation of trophoblast cells.     

Herbicidal pyridyl derivatives of aminomethylene-bisphosphonic acid inhibit plant glutamine synthetase

A series of aminomethylene-bisphosphonic acid derivatives, previously synthesized and shown to be endowed with herbicidal properties, were evaluated as potential inhibitors of plant glutamine synthetase. The cytosolic form of the enzyme was partially purified from rice cultured cells and assayed in the presence of millimolar concentrations of the compounds by means of three different assay methods, respectively measuring the hemibiosynthetic, the transferase, and the full biosynthetic reactions. Several compounds were found to exert a remarkable inhibition, with I(50) values similar to those obtained under the same conditions with a well-established inhibitor of glutamine synthetase, the herbicide phosphinothricin. Contrary to the reference compound, enzyme kinetics accounted for a reversible inhibition mechanism. The biological activity of the most active derivatives was further characterized by measuring free glutamine levels in cell suspension rice cultures following treatment with the inhibitors. Results confirmed their ability to interfere in vivo with nitrogen metabolism. A preliminary analysis of structure-activity relationship allowed it to be hypothesized that steric rather than electronic factors are responsible for the inhibitory potential of these compounds.     

Proteome changes in renal cortex and medulla induced by dietary supplementation with inulin‐type fructans in growing pigs

The aim of the study was to evaluate the influence of dietary supplementation with inulin extract from chicory root and dried chicory root on the protein profile of the renal cortex and medulla of growing pigs. The experiment was carried out on renal cortex and medulla tissue collected from 24 50‐day‐old PIC x Penarlan P76 crossbred piglets (males). Animals were divided into three dietary groups (n = 8) and fed with a control diet, diet supplemented with 2% inulin extract from chicory root and a diet supplemented with 4% dried chicory root. Kidney samples were collected after 40 days of feeding, and renal cortex and medulla proteins were separated by two‐dimensional electrophoresis. Protein identification was performed using MALDI‐TOF mass spectrometry. The diet supplemented with 2% chicory inulin induced significant expression changes of 20 and 26 protein spots in the renal cortex and medulla respectively. Supplementation with 4% dried chicory root triggered changes in the expression of 44 and 24 proteins in the renal cortex and medulla respectively. Both forms of chicory inulin‐type fructans effectively affected the expression of proteins involved in energy metabolism, heat shock proteins and other chaperones, cytoskeletal and cytoskeleton‐related proteins, as well as other proteins. Additionally, changes in transferrin abundance in both experimental groups suggested the significance of chicory fructan supplementation for iron absorption and bioavailability. In conclusion, 2% inulin extract from chicory root and 4% dried chicory root exerted a similar effect on changes in renal protein expression; however, more pronounced alterations were induced by dried chicory root. Nevertheless, further studies are needed for better understanding the mechanism underlying the effect of chicory inulin‐type fructans and their fermentation end products on the kidneys of growing pigs.