Frequency and Incidence of Pyrenochaeta terrestris in Root Internodes of Different Maize Hybrids

The frequency and incidence of Pyrenochaeta terrestris and symptom type on the roots of each internode of four maize hybrids of different maturity groups were studied 70 days after sowing. The fungus developed in the roots of all developed internodes (from the primary to the sixth or seventh internodes of all tested hybrids). The average frequency and incidence of P. terrestris in the roots of late and medium early maturity hybrids ranged from 29.5 to 55.2% and from 11.8 to 22.7%, respectively. The highest frequency of the fungus was at the 2nd root internode (93.3%), and its greatest incidence was detected in the mesocotyl of the medium early hybrid H‐1 (56.9%). Necrosis predominated in the roots of the medium early (i.e. medium late maturity hybrids, 44.5% and 44.3%, respectively), whereas reddish pink symptoms were recorded in the roots of the late hybrids (51% and 42.5%). Because the fungus always produces a distinctive red pigment on carnation leaf agar (CLA) in a light regime, these conditions can be recommended for the reliable identification of P. terrestris, even if pycnidia are not formed. These are the first reports of the successive distribution of the fungus in each maize root internode of different hybrids, as well as the use of CLA medium in the identification of the P. terrestris.     

Biopolymers from vegetable oils via catalyst- and solvent-free "click" chemistry: effects of cross-linking density

New monomers were prepared by introducing the azide groups in castor, canola, corn, soybean, and linseed oils. Polymerization of the azidated oils with alkynated soybean oil under thermal "click" chemistry conditions (without using a solvent or a catalyst) yielded fully cross-linked elastomers (1-5) of almost the same density (1.05 × 10(-3) kg/m(3)). The degree of cross-linking gradually increased from the castor-derived polymer (220 mol/m(3)) to the linseed-derived polymer (683 mol/m(3)). A systematic correlation between the degree of cross-linking and the thermal and mechanical properties was observed in these biopolymers. Tensile strength (0.62-3.39 MPa) and glass transition temperature (-5 to 16 °C) increased and the linear thermal expansion coefficient decreased in the series from the canola-derived polymer (2) to the linseed-derived polymer (5). The castor-derived polymer (1) that possesses an additional hydroxyl group per fatty acid chain behaved differently.     

The 4a/4a genotype of the VNTR polymorphism for endothelial nitric oxide synthase (eNOS) gene predicts risk for proliferative diabetic retinopathy in Slovenian patients (Caucasians) with type 2 diabetes mellitus

Thus far only a limited number of studies examined the association between endothelial nitric oxide synthase (eNOS) polymorphisms and proliferative diabetic retinopathy (PDR). In this report, two polymorphisms in the eNOS gene have been investigated, namely the 894G>T (Glu298Asp) and a 27 bp VNTR (4b/4a), to assess their possible relationships to PDR among Slovenian (Caucasians) type 2 diabetic patients. This cross-sectional case–control study enrolled 577 unrelated Slovenian subjects (Caucasians) with type 2 diabetes mellitus. The case group consisted of 172 patients with PDR and the control group had 405 patients who had no clinical signs of diabetic retinopathy (DR) but did have type 2 diabetes for more than 10 years’ duration. Genotyping of eNOS polymorphisms was carried out with conventional and real-time PCR assays. A significantly higher frequency of the eNOS minor “4a” allele was found in patients with PDR than in controls (23.6 versus 17.7%, p = 0.01). Moreover, the univariate analysis showed a significant association of the 27 bp VNTR 4a/4a genotype and PDR in the recessive model. The odds ratio (OR) of PDR for the 4a/4a genotype to 4b/4a plus 4b/4b was 2.9 (95% CI 1.3–6.2, p = 0.005). Further, the presence of 4a/a genotype was associated with a 3.4-fold (95% CI 1.4–8.6, p = 0.009) increased risk for PDR while adjusted for other risk factors. This is the first study to implicate eNOS 4a/4a homozygous deletion, and hence the “4a” allele, as the genetic risk factors for PDR in Caucasians.     

Epilepsy due to malformations of cortical development--correlation of clinical, MRI and Tc-99mECD SPECT findings

Malformations of cortical development (MCD) have been increasingly recognized as an important cause of intractable epilepsy. The aim of our study was to define epileptogenicity of MCDs by correlating MRI, EEG and semiology of epileptic attacks, and to determine the effect of MCD on drug resistant epilepsy. We also intended to reveal the utility of interictal single photo emission computed tomography (SPECT) in verification of MCD lesions and relative prevalence of different MCDs. Based on interictal EEG finding, semiology of the epileptic attacks and brain magnetic resonance imaging (MRI) "electroclinical epileptogenicity" of MCD was defined. Brain MRI revealed cortical dysplasia (CD) in nine patients, polymicrogyria in four patients, lissencephaly and schizencephaly in one patient each. Three patients had a combination of malformations. The localization of SPECT hypoperfusion corresponded to MCD lesion in ten (66.67%) patients. Electroclinically confirmed epileptogenicity of MCD overlapped with MR and interictal SPECT findings in fourteen (93.3%) and nine (60.0%) patients, respectively. Our study results demonstrated the MCD lesions to be highly epileptogenic and a frequent cause of intractability.     

Monitoring of aphid flight activities in?seed?potato?crops?in Serbia

Aphid flight activities in seed potato fields have been studied by the yellow water traps. It is a good method for monitoring aphids as vectors of viruses, but this study also showed it is a suitable method for insect-diversity research. During the four-year studies, over 11.500 specimens were collected and a total of 107 different taxa of aphids were identified. The most abundant species were polyphagous species, such as: Acyrthosiphon pisum (Haris), Aphis fabae Scopoli, Aphis gossypii Gloverand Brachycaudus helichrysi (Kaltenbach). The results of the studies show that diversity of aphids in different regions of Serbia is similar regardless of the altitude and the diversity of terrain. At most sites it ranged from 2 to 3. The highest value was recorded in Begeč, locality in northern part of Serbia, in year 2008, and it was 2.92. The maximum values of the Shannon-Weaver diversity index at all sites were recorded in the first weeks of the monitoring of aphid flight activities. Morisita-Horn similarity index shows no significant differences between sites regardless of altitudes. The sites are grouped by year, not by similarity of relief. In spite of these results, the Chi-square analysis showed highly significant difference in vector frequencies among seasons and sites with more pronounced differences for PVY. As a consequence of differences in vector frequencies, the vector pressure index in some regions was different also. The number of vectors and vector pressure index vary depending on the altitude of localities. At localities at altitudes under 1000 m, they were high. The highest index was at Kotraža, locality in central part of Serbia, in 2007, when PVY index exceeded the value of 180, while for PLRV it was 60. At high altitudes on mountain Golija, above 1100 m, the number of aphids was low, as well as the vector pressure index which indicates that these regions are suitable for producing virus-free seed potato.     

Biosynthesis of nucleic acids in pea (Pisum sativum L.) buds released of dominance

Biosynthesis of nucleic acids in the pea buds released from apical dominance by decapitation has been studied. The rate of biosynthesis of all nucleic acid classes separated by means of methylated albuminkieselgur (MAK) column chromatography was found to be increased in released pea buds as judged by the extent of orotic-6-¹⁴C acid incorporation. This increase has been observed in all experimental points examined (15, 24, 36 and 48 h after decapitation), being the most pronounced 15 h after decapitation. After that a certain decrease of the specific radioactivities of nucleic acids has been registered, but even 48 h after decapitation specific activities of the main nucleic acid classes were higher in comparison with those found in dominant buds. Variations of the free pyrimidine nucleotide pools were about 14% suggesting that this parameter did not influence the extent of the uptake of labelled orotic acid.     

A potential use of wild pea as a source of lower trypsin inhibitor activity

The aim of this work was to estimate the trypsin inhibitor activity (TIA) in seeds of cultivated pea varieties, wild varieties and selected crosses between varieties from the first group and wild pea varieties and to study the variation in genes coding trypsin inhibitors. Mean TIA in field pea varieties ranged from 3.12 TIU/mg of sample in field pea variety from Czech Republic to 12.90 TIU/mg of sample in field pea variety FP S4 of Serbian origin. Wild field pea varieties showed TIA between 0.98 TIU/mg of sample in Pisum elatius and 9.79 TIU/mg of sample in Pisum abyssinicum. Selected crosses between cultivated field pea varieties and Pisum elatius showed a decrease in TIA in comparison with a parent line that has higher TIA content. The PCR amplification resulted in variety-specific amplification. Varieties with low TIA activity showed amplification with At13/At5 primer pair, while varieties with higher TIA activity showed amplification with primer pairs At12/At5, At14/At5 and At14/At8. Thus, At13/At5 primer pair could be sufficient to distinguish most varieties. These markers can be applied during an early screening of the valuable materials for future breeding programs of pea cultivars with the low level of tripsin inhibitor.     

DNP-Enhanced MAS NMR: A Tool to Snapshot Conformational Ensembles of α-Synuclein in Different States

Intrinsically disordered proteins dynamically sample a wide conformational space and therefore do not adopt a stable and defined three-dimensional conformation. The structural heterogeneity is related to their proper functioning in physiological processes. Knowledge of the conformational ensemble is crucial for a complete comprehension of this kind of proteins. We here present an approach that utilizes dynamic nuclear polarization-enhanced solid-state NMR spectroscopy of sparsely isotope-labeled proteins in frozen solution to take snapshots of the complete structural ensembles by exploiting the inhomogeneously broadened line-shapes. We investigated the intrinsically disordered protein α-synuclein (α-syn), which plays a key role in the etiology of Parkinson’s disease, in three different physiologically relevant states. For the free monomer in frozen solution we could see that the so-called “random coil conformation” consists of α-helical and β-sheet-like conformations, and that secondary chemical shifts of neighboring amino acids tend to be correlated, indicative of frequent formation of secondary structure elements. Based on these results, we could estimate the number of disordered regions in fibrillar α-syn as well as in α-syn bound to membranes in different protein-to-lipid ratios. Our approach thus provides quantitative information on the propensity to sample transient secondary structures in different functional states. Molecular dynamics simulations rationalize the results.     

Influence of fasting and dopamine on the tissue catecholamines diurnal variations

To define the role of catecholamines (CA) in the metabolic adaptation to fasting we examined the effect of exogenous dopamine(DA) on heat production(HP) and CA content in the interscapular brown adipose tissue(IBAT) and adrenals of control-fed and 2-day fasted rats in the morning(M) and in the evening(E). DA stimulates HP in fed rats in the M by 45% but the thermogenic effect of this CA is markedly higher in the E. However, DA had no thermogenic effect in fasted rats. The tissue CA in fed rats fluctuates diurnally: in the IBAT noradrenaline(NA) was much higher in the E while adrenaline(A) in adrenals was lower. DA in fed rats did not change the adrenal A but reduced NA content both in the adrenals and in the IBAT all over the day. Fasting depleted A from adrenals but increased NA content both in the M and in the E. Unlike the adrenals in the IBAT fasting did not affect NA content. In the adrenal gland of fasted rats DA significantly increased the A content to the equal degree during the day, while this CA had no effect on NA content of the IBAT.