50 research outputs found
Characterization of Barley Genotypes and Their Biochemical Responses against Leaf Rust (Puccinia hordei) Disease under Cold Arid Environment
Cereal rust is one of the most damaging diseases of small-grain cereals. The fungus Puccinia hordei causes leaf rust in barley and other small grain crops. Puccinia hordei causes serious yield losses in the cultivating areas where susceptible and late-maturing barley varieties are cultivated. Therefore, rust-resistant barley cultivar is highly demandable for sustainable small-grain crop production. Improving barley yields and quality is one of the major objectives of barley breeding programs in our country. Exotic and indigenous germplasm is one of the best sources of resistance to biotic stresses in barley particularly leaf rust caused by Puccinia hordei. Hence, the present investigation was carried out to identify the resistance sources to P. hordei and incorporate them into the breeding programs for higher barley yields under changing climatic scenarios. The study aimed to identify new resistant cultivars in barley and other small grain crops. In this study, 100 barley genotypes (Hordeum vulgare L.) were considered for screening susceptibility to P. hordei causing rust disease. Several biochemical responses were analyzed in P. hordei infected barley genotypes. However, the variable response was observed among the 100 barley genotypes while those were screened against leaf rust disease under high altitude cold arid conditions of Ladakh, India. The efficiency of the 100 barley genotypes were categorized into different classes including high resistance (4 genotypes)>resistance (14 genotypes)> moderately resistance (20 genotypes)> moderately susceptible (33 genotypes)>moderately susceptible to susceptible (19 genotypes)> and susceptible (10 genotypes) based on plant response to P. hordei. Among the total genotypes, SHEIKH/KP-706, SHEIKH-B1, SHEIKH-636, and IC-062190 showed high resistance (8.07-8.63) as per the international leaf rust scale, while EC-667381, EC-667390, EC-667392, EC667396, EC-667417, Jyoti, EC-667434, EC-667442, EC-667445, and EC-667446 were found as susceptible (3.13-3.97) to P. hordei. The highly resistant genotypes accumulated a high level of phenols and flavonoids and cooperated with susceptible and other rest of the genotypes in response to P. hordei rust. The efficiency of plant immune response and or fitness to P. hordei was correlated to the disease susceptibility index of particular genotypes. This provides a new insight and the mechanistic basis of genotype-specific rust disease susceptibility against P. hordei. A large number of genotype-based studies at the field level could be useful to plant breeders and farmers for improving rust resistance in barley and other small-grain cereals
Polymorphisms in Toll-like receptor genes influence antibody responses to cytomegalovirus glycoprotein B vaccine
<p>Abstract</p> <p>Background</p> <p>Congenital Cytomegalovirus (CMV) infection is an important medical problem that has yet no current solution. A clinical trial of CMV glycoprotein B (gB) vaccine in young women showed promising efficacy. Improved understanding of the basis for prevention of CMV infection is essential for developing improved vaccines.</p> <p>Results</p> <p>We genotyped 142 women previously vaccinated with three doses of CMV gB for single nucleotide polymorphisms (SNPs) in TLR 1-4, 6, 7, 9, and 10, and their associated intracellular signaling genes. SNPs in the platelet-derived growth factor receptor (PDGFRA) and integrins were also selected based on their role in binding gB. Specific SNPs in TLR7 and IKBKE (inhibitor of nuclear factor kappa-B kinase subunit epsilon) were associated with antibody responses to gB vaccine. Homozygous carriers of the minor allele at four SNPs in TLR7 showed higher vaccination-induced antibody responses to gB compared to heterozygotes or homozygotes for the common allele. SNP rs1953090 in IKBKE was associated with changes in antibody level from second to third dose of vaccine; homozygotes for the minor allele exhibited lower antibody responses while homozygotes for the major allele showed increased responses over time.</p> <p>Conclusions</p> <p>These data contribute to our understanding of the immunogenetic mechanisms underlying variations in the immune response to CMV vaccine.</p
Osteopontin Impairs Host Defense during Established Gram-Negative Sepsis Caused by Burkholderia pseudomallei (Melioidosis)
Melioidosis is a severe tropical disease caused by infection with the bacterium Burkholderia (B.) pseudomallei. In northeast Thailand infection with this bacterium is the major cause of community-acquired septicemia with a mortality rate up to 40%. Extending the knowledge on the mechanisms of host defense against B. pseudomallei infection would be helpful to improve treatment of this severe illness. Osteopontin (OPN) is a cytokine that is involved in several immune responses that occur during bacterial infection. In this study, we investigated levels of OPN in patients with melioidosis, and studied the function of OPN during experimental melioidosis in mice. We found that OPN concentrations were elevated in patients with severe melioidosis, and that high OPN concentrations are associated with poor outcome in patients with melioidosis. In experimental melioidosis in mice plasma and lung OPN levels were also increased. Moreover, mice with melioidosis that were deficient for OPN demonstrated reduced bacterial numbers in their lungs, diminished pulmonary tissue injury, and decreased neutrophil infiltration into the lungs during established melioidosis. Moreover, these mice displayed a delayed mortality as compared to control mice. In conclusion, sustained production of OPN impairs host defense during melioidosis
Pathogen Specific, IRF3-Dependent Signaling and Innate Resistance to Human Kidney Infection
The mucosal immune system identifies and fights invading pathogens, while allowing non-pathogenic organisms to persist. Mechanisms of pathogen/non-pathogen discrimination are poorly understood, as is the contribution of human genetic variation in disease susceptibility. We describe here a new, IRF3-dependent signaling pathway that is critical for distinguishing pathogens from normal flora at the mucosal barrier. Following uropathogenic E. coli infection, Irf3−/− mice showed a pathogen-specific increase in acute mortality, bacterial burden, abscess formation and renal damage compared to wild type mice. TLR4 signaling was initiated after ceramide release from glycosphingolipid receptors, through TRAM, CREB, Fos and Jun phosphorylation and p38 MAPK-dependent mechanisms, resulting in nuclear translocation of IRF3 and activation of IRF3/IFNβ-dependent antibacterial effector mechanisms. This TLR4/IRF3 pathway of pathogen discrimination was activated by ceramide and by P-fimbriated E. coli, which use ceramide-anchored glycosphingolipid receptors. Relevance of this pathway for human disease was supported by polymorphic IRF3 promoter sequences, differing between children with severe, symptomatic kidney infection and children who were asymptomatic bacterial carriers. IRF3 promoter activity was reduced by the disease-associated genotype, consistent with the pathology in Irf3−/− mice. Host susceptibility to common infections like UTI may thus be strongly influenced by single gene modifications affecting the innate immune response
AI is a viable alternative to high throughput screening: a 318-target study
: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery
Broadband multi-wavelength properties of M87 during the 2017 Event Horizon Telescope campaign
High Energy AstrophysicsInstrumentatio
PHYSIO-BIOCHEMICAL AND MOLECULAR CHARACTERIZATION FOR DROUGHT TOLERANCE IN RICE GENOTYPES AT EARLY SEEDLING STAGE
WOS: 000389137600010The aim of the current investigation was to study the influence of drought-stressed by using PEG on some rice genotypes at seedling stage. The performance was judged by growth, physiological, biochemical and molecular constituents at seedling stage. The results of study suggested that growth attributes were reduced under different drought stress (70 and 140 g/L PEG) in most of the cases as compared with control. Among various tested genotypes IRAT 259, Line 7 and Line 8 exhibited the lowest reduction values of relative water content, chlorophyll content and membrane stability index at 70 and 140 drought levels. The Line 8 produced the highest amount of proline under stress conditions which is indicating its highest tolerance to drought stress. The antioxidant enzymes such as catalase, peroxidase and polyphenol oxidase were induced by the drought levels. The growing expressions of antioxidant enzymes assist the plant for adaptation of plant under environmental conditions and tolerate stress. The IRAT 259 has highest increase percentage in antioxidant enzymes under stress. Total sixteen SSR primers examine for characterizing the power of each SSR primer by calculating polymorphic information contents and a total of 41 alleles were amplified using 16 SSR primers. The variation in number of amplified alleles per primer ranged from one allele as for wmc27 to five alleles for wmc179 and wmc 215, with an average of 2.56 alleles. The highest value was 100% polymorphism belonged to 13 out of the 16 primers. Phylogenetic analyses per primer were ranged from 0.00 to 0.794 with an average of 0.427. Average observed heterozygosity ranged from 0.00 to 0.670 with an average of 0.45. It was found the value of heterozygosity was 0.00 to 0.670 and the mean value of heterozygosity was 0.45. On the basis of phenotypic and genetypic (reaction with markers) performances under drought stress conditions, the Line 8 and the Line 7 can be recommended as a drought tolerant and a drought sensitive, respectively. This result can be acclaimed the important source for genetic diversity of rice in future breeding programs
Properties of a glow discharge lamp of the Grimm type
This work describes a glow discharge lamp of the Grimm type. The lamp proved to be stable
for periods up to about 2 hours. The intensity to background ratio of the Cu I 237.4 nm line from a
brass target was found to be 200. Analysis of the experimental results showed that the discharge
potential depends on the discharge current through a power law . K and S are
also power functions of the pressure P. Intensity was measured as a function of the lamp
operating parameters (V, i, and P). Self-absorption was shown to be insignificant. The
sputtering rate Q was found to vary with the lamp power W=Vi, Q=C Wm where C
and m are constants
Phylogenetic Analysis of Ryegrass (<i>Lolium rigidum</i>) Populations and the Proliferation of ALS Resistance in Saudi Arabia
Morphological and simple sequence repeat (SSR) approaches were used to determine the genetic diversity of 29 ryegrass (Lolium rigidum) genotypes belonging to eight populations collected from several regions in Saudi Arabia. In this study, 50 in Silico-developed SSR markers derived from genomic and expressed sequence tag (EST) microsatellites were examined. Analysis of variance showed highly significant differences in all studied traits. Cluster analysis based on the morphological data of the 29 Lolium genotypes and using PAST (paleontological statistics) software was performed. According to the results, clustering was based mostly on genotype location. The sensitive genotypes for herbicide were clustered in one group. In addition, using EST-SSR markers, we observed the existence of a considerable number of genetic variations among Lolium genotypes. From these markers, only 31 produced reasonable amplification products. The results showed that 23 SSR markers revealed that 74.19% were polymorphic. The number of alleles detected per primer ranged from one to five in the primer LTC SSR1. The tested primers amplified 1434 bands across eight populations, with an average of 46.26 bands per primer. The polymorphism information content (PIC) values ranged from 0.11 to 0.76 for the primers LT EST-SSR5 and LTC SSR1. The unweighted pair group method with arithmetic average (UPGMA) clustering of the 29 genotypes representing eight populations was based essentially on their locations and herbicide-tolerance levels. Most of the populations formed into four clusters, together representing genotypes. Moreover, the tolerant populations were distinguished from the sensitive ones. The relationship between the genetic diversity and geographical source of Lolium rigidum populations of Saudi Arabia was revealed through this study. The results showed that the efficiency of developed SSR markers are transferable across species. They have been helpful to assess the genetic diversity of the ryegrass population as this could be applied to differentiate between tolerant and sensitive populations of ryegrass
Sputtering in a glow discharge lamp of the Grimm type
The sputtering rate (Q), in glow discharge, was measured as a
function of the discharge power (W). An empirical relation could be
obtained having the form , with the constants and m. The
equation was compared with theoretical derived equation of Takatsu and
Toda, which is based on the mechanism of momentum transfer. Takatsu
and Toda theoretical relationship had to be rearranged to obtain the same
relationship between the sputtering rate (Q) and the discharge (W). The
experimental data obtained in the present work as well as by Boumans
and Takatsu and Toda were analysed on the bases of the obtained equation.
This analysis revealed that the constants appearing in the Q-W equations
are pressure dependent. These dependences are described and discussed