Characterization of Clavibacter michiganensis subsp. michiganensis strains from recent outbreaks of bacterial wilt and canker in Serbia

Sixty-eight Clavibacter michiganensis subsp. michiganensis (Cmm) strains from recent outbreaks of bacterial wilt and canker in Serbia were collected from several tomato growing regions during a three-year period. The pathogen was identified based on bacteriological characteristics and pathogenicity tests and the identity of strains was confirmed by DAS ELISA and PCR amplification using primers CMM5/6 and PSA4/R. The strains showed homogeneity in biochemical and physiological properties. However, pathogenicity tests revealed differences in virulence that are presumably due to a loss of the pat-1 gene. Further strain characterization using DNA-based methods revealed a high diversity of the Serbian Cmm strains. Based on multi-locus sequence typing (MLST) analyses of five genes, Cmm strains were divided into seven groups. The pulsed-field gel electrophoresis (PFGE) pattern of a selection of strains supported the groupings based on trees of the kdpA/sdhA sequences. On the other hand, groupings made according to PFGE and MLST were not correlated to plasmid content in all cases. This study suggested that high genetic variability of the Serbian Cmm strains was detected both in MLST and PFGE analyses, and could have resulted either from new Cmm strains being introduced by seeds from different origins or as a consequence of an intraspecific hybridization process. In addition, this study proposed MLST as an efficient tool in epidemiological studies, population biology investigations and tracking the routes of transmission of pathogens. Four of the five house-keeping genes (kdpA, sdhA, ligA and gyrB) selected to characterize Cmm strains proved to be suitable for the MLST analysis. This is the first study carried out on the characterization of Cmm using MLST.     

Changes in Ensembles’ Thermal Insulation According to Garment’s Fit and Length Based on Athletic Figure

The purpose of this paper is to analyse the impact of design solutions on the thermal insulation of the garments and the ensembles. Previous studies investigated the microclimatic air gaps and volumes, however only under the first - and the second - layered clothing. Since none of the previous studies covered three - layered ensembles, in this study ensembles were accompanied by jackets of different fit and length to investigate the ensembles’ thermal insulation. Variants of bomber jacket differ in the amount of the ease allowance, while variants of the parka differ in length. The thermal insulation of the ensembles increased for 21.6 to 59.7 % when one of the jacket variants was added as the outerwear garment. A threshold volume, after which the thermal insulation will start to decrease due to convection, wasn’t determined for the outerwear third - layered garments nor was the impact of the length of the garment on the thermal insulation clearly stated. This study involved laboratory testing of garments and ensembles by 3D body scanning and thermal manikin measurements. To evaluate the volume of the microclimatic air volume the accurate 3D body scanning was used and the impact of the microclimatic volume on the ensemble’s insulation was tested. The thermal insulation for the selected outerwear garments and afterwards ensembles was measured by resting thermal manikin. Analysis of the results obtained from tests, showed that the garments’ fit and length can be used to model the overall thermal insulation of the ensembles. The ensembles insulation enlargement was measured for microclimatic volumes up to 33.57 dm³ (measured with ensembles accompanied with bomber jacket). The study proved that the limiting microclimatic volume is greater for three - layered clothing, than previously reported. The overall ensembles’ insulation increased simultaneously with the length enlargement (measured with ensembles accompanied with parka jacket). Findings will be of help in the future research on garments and ensembles thermal properties modelled through the design process and the construction.     

Variation in chromosome numbers and nuclear DNA contents in genetic resources of Lactuca L. species (Asteraceae)

Fifty accessions of 25 Lactuca species,L. serriola ×L. sativa and Mycelismuralis were analyzed for chromosome number and relative DNA amountvariation. In the majority of Lactuca species studiedchromosome counts, as earlier reported (n = 8, 9, 17), were verified; however,for L. dregeana andL. homblei (probablyL. schweinfurthii orL. longespicata) the chromosome number(n = 9) was determined for the first time. Relative nuclear DNA content,estimated by using flow cytometry (DAPI staining), showed that 2C DNA contentranged from 2.02 pg in L.capensis to 17.96 pg inL. canadensis. Statistical and clusteranalysis of data based on relative nuclear DNA contents correspond fairly wellwith recently accepted taxonomic classification of the genusLactuca. However, the position of certain species as wellas clarification of taxonomic determinations of someLactuca accessions needs further examination.     

Characterization of "lettucine", a serine-like protease from Lactuca sativa leaves, as a novel enzyme for milk clotting

In this work we focused on the characterization of a novel plant rennet purified from lettuce leaves (Lactuca sativa L. cv Romana). The lettuce protease, lettucine, showed trypsin-like, SV8-like, and caseinolytic activities. Although the enzyme did not recognize peptides having hydrophobic amino acid residues in the P(1) position of the target bond, it did show milk-clotting activity, suggesting that different bonds rather than the Phe(105)-Met(106) of the kappa-casein might be cleaved, still inducing milk-clotting. The enzyme exhibited proteolytic activity toward alpha-casein, beta-casein, kappa-casein, and milks with different fat contents, with the highest activity observed with partially skimmed milk, total casein, and alpha- and kappa-casein. SDS-PAGE studies showed that lettucine cleaved alpha-casein, beta-casein, and kappa-casein. In particular, we showed that alpha-casein breakdown occurred even though total casein or milks were supplied, suggesting that the lettuce enzyme is able to operate a significant disorganization of the casein's micellar structure. Moreover, the proteolytic activity of the enzyme analyzed under various technological parameters, such as temperature and pH, indicated that the lettuce enzyme is highly consistent with the milk-clotting process.     

Amendment Type and Dose Effects onto Coexisting Copper,Lead, and Nickel Ions Distribution in Soil

The use of soil additives for toxic metals chemical stabilization aims to decrease in situ the pollutants’ mobility and availability. In this study, the effectiveness of rinsed red mud (RBRM) and annealed animal bones (B400) was compared in terms of Cu, Pb and Ni stabilization in two contaminated soils with contrasting properties Dystric Cambisol (CM dy) and Rendzic Leptosol (LP rz). The mobility of metals in unamended soil samples (control) and samples amended with 1% and 5% of selected additives were compared using sequential extraction protocol. The relative content of metals in readily and potentially available fractions was higher in CM dy (62% Pb, 13% Cu, and 31% Ni in exchangeable fraction) than in LP rz (<?5% of Pb, Cu, Ni in exchangeable fraction). In CM dy, both additives have caused a decrease in metal mobility with an increase of their doses. The effect of 5% sorbent addition was most pronounced related to Pb immobilization, provoking decrease of exchangeable Pb content to <?10%. Furthermore, B400 addition has redistributed investigated metals from the exchangeable to the residual phase more effectively than RBRM, and its effect on metal mobility decreased in the order Pb?>?Cu?>?Ni. Amending of LP rz soil had limited effects with no apparent decrease in exchangeable metal content. The effects of soil type variation, the type of additive and the additive dose onto metal mobility were compared according to ANOVA results. The content of readily and potentially available forms of metals was found to be (i) significantly correlated with all investigated variables for Pb, (ii) significantly correlated with soil type for Cu, and (iii) not in significant correlation with selected variables for Ni. Complex impacts of soil properties and treatment conditions on the mobility of co-contaminants emphasize the need for an individual approach to each case of contamination.     

Effects of milling and baking technologies on levels of deoxynivalenol and its masked form deoxynivalenol-3-glucoside

The co-occurrence of the major Fusarium mycotoxin deoxynivalenol (DON) and its conjugate deoxynivalenol-3-glucoside (DON-3-Glc) has been documented in infected wheat. This study reports on the fate of this masked DON within milling and baking technologies for the first time and compares its levels with those of the free parent toxin. The fractionation of DON-3-Glc and DON in milling fractions was similar, tested white flours contained only approximately 60% of their content in unprocessed wheat grains. No substantial changes of both target analytes occurred during the dough preparation process, i.e. kneading, fermentation, and proofing. However, when bakery improvers enzymes mixtures were employed as a dough ingredient, a distinct increase up to 145% of conjugated DON-3-Glc occurred in fermented dough. Some decrease of both DON-3-Glc and DON (10 and 13%, respectively, compared to fermented dough) took place during baking. Thermal degradation products of DON, namely norDON A, B, C, D, and DON-lactone were detected in roasted wheat samples and baked bread samples by means of UPLC-Orbitrap MS. Moreover, thermal degradation products derived from DON-3-Glc were detected and tentatively identified in heat-treated contaminated wheat and bread based on accurate mass measurement performed under the ultrahigh mass resolving power. These products, originating from DON-3-Glc through de-epoxidation and other structural changes in the seskviterpene cycle, were named norDON-3-Glc A, B, C, D, and DON-3-Glc-lactone analogically to DON degradation products. Most of these compounds were located in the crust of experimental breads.     

A heme export protein is required for red blood cell differentiation and iron homeostasis

Hemoproteins are critical for the function and integrity of aerobic cells. However, free heme is toxic. Therefore, cells must balance heme synthesis with its use. We previously demonstrated that the feline leukemia virus, subgroup C, receptor (FLVCR) exports cytoplasmic heme. Here, we show that FLVCR-null mice lack definitive erythropoiesis, have craniofacial and limb deformities resembling those of patients with Diamond-Blackfan anemia, and die in midgestation. Mice with FLVCR that is deleted neonatally develop a severe macrocytic anemia with proerythroblast maturation arrest, which suggests that erythroid precursors export excess heme to ensure survival. We further demonstrate that FLVCR mediates heme export from macrophages that ingest senescent red cells and regulates hepatic iron. Thus, the trafficking of heme, and not just elemental iron, facilitates erythropoiesis and systemic iron balance.     

Preliminary nutrient diagnosis norms and optimum ranges in potted ornamental plants grown under saline conditions

Abstract

Diagnosis and Recommendation Integrated System (DRIS) norms for nitrogen (N), phosphorus (P), potassium (K), sulfur (S), chlorine (Cl) and sodium (Na) and nutrient sufficiency ranges for Aloe vera, Kalanchoe blossfeldiana, Lavandula multifidi, and Rosmarinus officinalis were based on two experiments. DRIS norms and nutrient ratios were computed and selected. Nutrient sufficiency ranges were developed using the data of the whole population according to the DRIS approach. The development of DRIS norms revealed that only K. blossfeldiana and R. officinalis showed limiting nutrients. The nutrient sufficiency ranges for each species expressed in mg g^?1 were: A. vera (N (9–28), P (1–3), K (37–48), S (8–10), Cl (47–50), Na (17–37)), K. blossfeldiana (N (16–22), P (2–3), K (35–39), S (7–10), Cl (45–54), Na (7–19)), L. multifida (N (15–16), P (1–7), K (18–37), S (7–8), Cl (41–60), Na (21–49)), R. officinalis (N (9–23), P (2–5), K (31–48), S (7–8), Cl (36–40), Na (7–12)). The establishment of these DRIS norms will useful to manage the nutritional status of the species studied under saline conditions.