Phylogenetic relationships among Phytopythium species,and re-evaluation of Phytopythium fagopyri comb. nov., recovered from damped-off buckwheat seedlings in Japan

We examined the phylogenetic relationships among Phytopythium species using the rDNA ITS region, the LSU rDNA region, and the mitochondrial coxI and coxII genes. The genus was resolved into three monophyletic clades (1–3). Clade 1 was the largest clade, composed of 12 known species. Clades 2 contained two known and one new species candidate and clade 3 contained two known species. Three isolates in clade 2 (FP1, HonMa, and a strain designated as P. helicoides CBS293.35) formed a monophyletic group with high bootstrap support. This monophyletic group was distinct from P. helicoides sensu stricto. All three isolates came from damped-off buckwheat seedlings. The isolates were morphologically identical with one another and were characterized by globose, sub-globose, or pyriform sporangia with apical papillae; internally or internally nested proliferating sporangia; simple sympodia; coiling antheridial stalks; and wavy, sessile, or clavate antheridial cells. The isolates grew at temperatures between 15 °C and 40 °C, and the optimum temperature was 30 °C, with a radial growth rate of 20 mm/24 h. The phylogenetic and morphological analyses indicated that these isolates belong to a distinct species, which was previously under the genus Pythium, named here Phytopythium fagopyri comb. nov.     

Assembly of cyclic enterobacterial common antigen in Escherichia coli K-12

We describe here the purification and quantification of a water-soluble cyclic form of enterobacterial common antigen (ECA(CYC)) from Escherichia coli K-12 as well as information regarding its subcellular location and the genetic loci involved in its assembly. Structural characterization of purified ECA(CYC) molecules obtained from E. coli K-12 revealed that they uniformly contained four trisaccharide repeat units, and they were substituted with from zero to four O-acetyl groups. Cells from overnight cultures contained approximately 2 microg ECA(CYC) per milligram (dry weight), and cell fractionation studies revealed that these molecules were localized exclusively in the periplasm. The synthesis and assembly of ECA(CYC) were found to require the wzxE and wzyE genes of the wec gene cluster. These genes encode proteins involved in the transmembrane translocation of undecaprenylpyrophosphate-linked ECA trisaccharide repeat units and the polymerization of trisaccharide repeat units, respectively. Surprisingly, synthesis of ECA(CYC) was dependent on the wzzE gene, which is required for the modulation of the polysaccharide chain lengths of phosphoglyceride-linked ECA (ECA(PG)). The presence of ECA(CYC) in extracts of several other gram-negative enteric organisms was also demonstrated; however, it was not detected in cell extracts of Pseudomonas aeruginosa. These data suggest that in addition to ECA(PG), ECA(CYC) may be synthesized in many, if not all, members of the Enterobacteriaceae.     

Antagonistic potentiality of Trichoderma harzianum towards seed-borne fungal pathogens of winter wheat cv. Protiva in vitro and in vivo

The antagonistic effect of Trichoderma harzianum on a range of seed-borne fungal pathogens of wheat (viz. Fusarium graminearum, Bipolaris sorokiniana, Aspergillus spp., and Penicillium spp.) was assessed. The potential of T. harzianum as a biocontrol agent was tested in vitro and under field conditions. Coculture of the pathogens and Trichoderma under laboratory conditions clearly showed dominance of T. harzianum. Under natural conditions, biocontrol effects were also obtained against the test fungi. One month after sowing, field emergence (plant stand) was increased by 15.93% over that obtained with the control treatment, and seedling infection was reduced significantly. Leaf blight severity was decreased from 22 to 11 at the heading stage, 35 to 31 at the flowering stage, and 86 to 74 at the grain filling stage. At harvest, the number of tillers per plant was increased by 50%, the yield was increased by 31.58%, and the 1,000-seed weight was increased by 21%.     

Targeting peptidylarginine deiminase reduces neutrophil extracellular trap formation and tissue injury in severe acute pancreatitis

Recent evidence suggests that neutrophil extracellular traps (NETs) play an important role in the development of acute pancreatitis (AP). Herein, we examined the role of peptidylarginine deiminase (PAD), which has been shown to regulate NET formation, in severe AP. AP was induced by retrograde of taurocholate infusion into pancreatic duct in C57BL/6 mice. PAD was pharmacologically inhibited using Cl-amidine, a pan-PAD inhibitor. Pancreata were collected, and histones, citrullinated histone 3, chemokines, myeloperoxidase, and NETs were quantified. Chemokines, matrix metalloproteinase-9 (MMP-9), interleukin-6 (IL-6), and DNA-histone complexes were determined in plasma samples. Infusion of taurocholate induced formation of NETs in pancreatic tissues of mice. Pretreatment with Cl-amidine markedly reduced the NET formation in the inflamed pancreas. Moreover, inhibition of PAD decreased the levels of blood amylase as well as edema, acinar cell necrosis, hemorrhage, and neutrophil infiltration in the pancreas of animals with AP. Administration of Cl-amidine attenuated the myeloperoxidase levels in the pancreas and lung of mice exposed to taurocholate. In addition, Cl-amidine decreased pancreatic levels of CXC chemokines, plasma levels of IL-6, and MMP-9 in mice with severe AP. This study shows that Cl-amidine is a potent inhibitor of NET formation in severe AP. Also, our results suggest that PAD regulates pathological inflammation and tissue damage in the inflamed pancreas. Thus, targeting PAD might be a useful strategy to treat patients with severe AP.     

Curcumin Mimics the Neurocognitive and Anti-Inflammatory Effects of Caloric Restriction in a Mouse Model of Midlife Obesity

Dietary curcumin was studied for its potential to decrease adiposity and reverse obesity- associated cognitive impairment in a mouse model of midlife sedentary obesity. We hypothesized that curcumin intake, by decreasing adiposity, would improve cognitive function in a manner comparable to caloric restriction (CR), a weight loss regimen. 15-month-old male C57BL/6 mice were assigned in groups to receive the following dietary regimens for 12 weeks: (i) a base diet (Ain93M) fed ad libitum (AL), (ii) the base diet restricted to 70% of ad libitum (CR) or (iii) the base diet containing curcumin fed AL (1000 mg/kg diet, CURAL). Blood markers of inflammation, interleukin 6 (IL-6) and C-reactive protein (CRP), as well as an indicator of redox stress (GSH: GSSG ratio), were determined at different time points during the treatments, and visceral and subcutaneous adipose tissue were measured upon completion of the experiment. After 8 weeks of dietary treatment, the mice were tested for spatial cognition (Morris water maze) and cognitive flexibility (discriminated active avoidance). The CR group showed significant weight loss and reduced adiposity, whereas CURAL mice had stable weight throughout the experiment, consumed more food than the AL group, with no reduction of adiposity. However, both CR and CURAL groups took fewer trials than AL to reach criterion during the reversal sessions of the active avoidance task, suggesting an improvement in cognitive flexibility. The AL mice had higher levels of CRP compared to CURAL and CR, and GSH as well as the GSH: GSSG ratio were increased during curcumin intake, suggesting a reducing shift in the redox state. The results suggest that, independent of their effects on adiposity; dietary curcumin and caloric restriction have positive effects on frontal cortical functions that could be linked to anti-inflammatory or antioxidant actions.     

Cardiac Sympathetic Denervation in 6-OHDA-Treated Nonhuman Primates

Cardiac sympathetic neurodegeneration and dysautonomia affect patients with sporadic and familial Parkinson''s disease (PD) and are currently proposed as prodromal signs of PD. We have recently developed a nonhuman primate model of cardiac dysautonomia by iv 6-hydroxydopamine (6-OHDA). Our in vivo findings included decreased cardiac uptake of a sympathetic radioligand and circulating catecholamines; here we report the postmortem characterization of the model. Ten adult rhesus monkeys (5–17 yrs old) were used in this study. Five animals received 6-OHDA (50 mg/kg iv) and five were age-matched controls. Three months post-neurotoxin the animals were euthanized; hearts and adrenal glands were processed for immunohistochemistry. Quantification of immunoreactivity (ir) of stainings was performed by an investigator blind to the treatment group using NIH ImageJ software (for cardiac bundles and adrenals, area above threshold and optical density) and MBF StereoInvestigator (for cardiac fibers, area fraction fractionator probe). Sympathetic cardiac nerve bundle analysis and fiber area density showed a significant reduction in global cardiac tyrosine hydroxylase-ir (TH; catecholaminergic marker) in 6-OHDA animals compared to controls. Quantification of protein gene protein 9.5 (pan-neuronal marker) positive cardiac fibers showed a significant deficit in 6-OHDA monkeys compared to controls and correlated with TH-ir fiber area. Semi-quantitative evaluation of human leukocyte antigen-ir (inflammatory marker) and nitrotyrosine-ir (oxidative stress marker) did not show significant changes 3 months post-neurotoxin. Cardiac nerve bundle α-synuclein-ir (presynaptic protein) was reduced (trend) in 6-OHDA treated monkeys; insoluble proteinase-K resistant α-synuclein (typical of PD pathology) was not observed. In the adrenal medulla, 6-OHDA monkeys had significantly reduced TH-ir and aminoacid decarboxylase-ir. Our results confirm that systemic 6-OHDA dosing to nonhuman primates induces cardiac sympathetic neurodegeneration and loss of catecholaminergic enzymes in the adrenal medulla, and suggests that this model can be used as a platform to evaluate disease-modifying strategies aiming to induce peripheral neuroprotection.     

Accurate Phylogenetic Tree Reconstruction from Quartets: A Heuristic Approach

Supertree methods construct trees on a set of taxa (species) combining many smaller trees on the overlapping subsets of the entire set of taxa. A ‘quartet’ is an unrooted tree over taxa, hence the quartet-based supertree methods combine many -taxon unrooted trees into a single and coherent tree over the complete set of taxa. Quartet-based phylogeny reconstruction methods have been receiving considerable attentions in the recent years. An accurate and efficient quartet-based method might be competitive with the current best phylogenetic tree reconstruction methods (such as maximum likelihood or Bayesian MCMC analyses), without being as computationally intensive. In this paper, we present a novel and highly accurate quartet-based phylogenetic tree reconstruction method. We performed an extensive experimental study to evaluate the accuracy and scalability of our approach on both simulated and biological datasets.     

Estimation of Genetic Divergence and Character Association Studies in Local and Exotic Diversity Panels of Soybean (<i>Glycine max</i> L.) Genotypes

The availability of favorable genetic diversity is a thriving vitality for the success of a breeding program. It provides a firm basis of selecting superior breeding lines for the development of high yielding crop genotypes. In this context, present investigation aimed to generate information on genetic divergence and character association in a diversity panel of 123 local and exotic soybean genotypes. Analysis of variance revealed significant response of the evaluated genotypes based on studied attributes. It depicted the probability of selecting desirable soybean genotypes by focusing on character association studies and genetic diversity analysis. Correlation analysis revealed that seed yield per plant showed high positive correlation with 100-seed weight followed by pods per plant and plant height. Furthermore, path coefficient analysis exposed that pods per plant had maximum direct contribution in seed yield per plant followed by 100-seed weight, days to flowering and SPAD measurement. Genotype named “G-10” showed maximum yield per plant followed by 24607, G-52, 24593, Arisoy, 24566, 17426, A-3127, 24570 and 24567. Genetic diversity analysis grouped the evaluated germplasm into 17 clusters. All clusters showed zero intra-cluster variability; while inter-cluster divergence ranged from 9.00 to 91.11. Cluster V showed maximum inter-cluster distance with cluster XII followed by that of between V and VIII. Moreover, cluster IV with superior genotypes (G-10, 24607, 24593 and 24566), VI (17426 and 24567), XIII (24570) and X (Arisoy and G-52) showed above mean values for most of the studied characters. Overall, the results of hybridization between the superior genotypes of these cluster pairs might be useful for soybean breeding with improving agronomic traits and adaptability.     

Characterisation of the wheat Mr 15000 “grain-softness protein” and analysis of the relationship between its accumulation in the whole seed and grain softness

The Mr 15000 protein associated with water-washed wheat starch granules from soft wheats was shown to be heterogeneous: it could be divided into a fraction containing one or more-amylase inhibitor subunits and a fraction largely composed of a previously uncharacterised polypeptide(s) referred to as the grainsoftness protein (GSP). The major N-terminal sequence and sequences of peptides derived from protease digests of GSP are reported. An antiserum specific for GSP was used to show that GSP accumulated in both hard and soft wheat grains, but the GSP in soft grains associated more strongly with starch granules than the GSP in hard grains. A positive correlation between grain softness and accumulation of GSP in the seed was demonstrated for a range of cultivars. This differs from the qualitative relationship, based on the isolated starch fraction, between GSP and grain softness that has already been reported. Analysis of wholemeal extracts with the antiserum demonstrated that the accumulation of GSP in the seed was dependent on the short arm of chromosome 5D, which also encodes theHa locus. In addition, examination of near-isogenic lines differing in hardness indicated that the gene(s) controlling GSP was (were) linked with theHa locus. The findings indicate that GSP may be the product of theHa locus and thus be the major factor that determines the milling characteristics of bread wheats.