Metabolomic Profiling and Neuroprotective Effects of Purslane Seeds Extract Against Acrylamide Toxicity in Rat’s Brain

Neurochemical Research - Acrylamide (ACR) is an environmental pollutant with well-demonstrated neurotoxic and neurodegenerative effects in both humans and experimental animals. The present study...     

MicroRNA signature in hepatocellular carcinoma patients: identification of potential markers

MicroRNAs (miRNAs) play important roles in liver pathologies and they are potential biomarkers for diagnosis of liver diseases progression. Changes in miRNA sera expression can be used as non-invasive biomarkers for hepatocellular carcinoma (HCC). The aim of the study was to identify the miRNome profiling of HCC and its diagnostic value in distinguishing HCC from healthy individuals. Expression profiles of miRNAs in serum samples of 20 HCC patients and 10 healthy controls were detected. Whole miRNome profiling was done using next generation sequencing. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic performance of the deregulated miRNAs for discriminating HCC cases from healthy controls. MiRNA 142 was highly expressed in HCC (P value?=?0.023) while miRNAs 191, 22, and 126 were higher in the controls (P value?=?0.005, 0.034, 0.010 respectively). We have identified 5 novel miRNAs and they were highly expressed in HCC than controls. Analysis of ROC curve demonstrated that these deregulated miRNAs can be used as a reliable biomarker for detection of HCC with high diagnostic accuracy (AUC?=?0.93). We have detected a panel of serum miRNAs that can be used as a reliable noninvasive screening biomarker of HCC. The study recommends further research to shed light on a possible role of the newly discovered novel miRNAs in HCC pathogenesis.

     

Hydrogen peroxide detoxifying enzymes show different activity patterns in host and non-host plant interactions with Magnaporthe oryzae Triticum pathotype

Wheat blast caused by the hemibiotroph fungal pathogen Magnaporthe oryzae Triticum (MoT) pathotype is a destructive disease of wheat in South America, Bangladesh and Zambia. This study aimed to determine and compare the activities of antioxidant enzymes in susceptible (wheat, maize, barley and swamp rice grass) and resistant (rice) plants when interacting with MoT. The activities of reactive oxygen species-detoxifying enzymes; catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX), glutathione S-transferase (GST), peroxidase (POX) were increased in all plants in response to MoT inoculation with a few exceptions. Interestingly, an early and very high activity of CAT was observed within 24 h after inoculation in wheat, barley, maize and swamp rice grass with lower H₂O₂ concentration. In contrast, an early and high accumulation of H₂O₂ was observed in rice at 48 hai with little CAT activity only at a later stage of MoT inoculation. The activities of APX, GST and POD were also high at an early stage of infection in rice. However, these enzymes activities were very high at a later stage in wheat, barley, maize and swamp rice grass. The activity of GPX gradually decreased with the increase of time in rice. Taken together, our results suggest that late and early inductions of most of the antioxidant enzyme activities occurs in susceptible and resistant plants, respectively. This study demonstrates some insights into physiological responses of host and non-host plants when interacting with the devastating wheat blast fungus MoT, which could be useful for developing blast resistant wheat.     

Redox cycling of adrenaline and adrenochrome catalysed by mitochondrial Complex I

Complex I in bovine heart submitochondrial particles catalyses the NADH-supported generation of superoxide anion; adrenaline is oxidised by superoxide to adrenochrome that, on its hand, is reduced by Complex I, thus establishing a redox cycle that amplifies the superoxide production. The routes in Complex I for superoxide formation and for adrenochrome reduction appear to be different, since they have a different sensitivity to Complex I inhibitors. The results are discussed in terms of current assays for superoxide detection and of pathologies linked to catecholamine oxidation.     

Non-gel based techniques for plant pathogen genotyping

The introduction of real-time PCR technology has significantly improved and simplified the quantification of nucleic acids, and this technology has become an invaluable tool for many scientists working in different disciplines. Particularly in the field of molecular diagnostics and genotyping, real-time PCR-based assays have gained favour in the recent past. Rapid real-time PCR diagnosis can result in appropriate control measures and eradication procedures in a faster and more accurate way than traditional methods based on pathogen isolation. Real-time quantitative PCR represents a highly sensitive and powerful technique for the gel-free detection of nucleic acids. In this review, the main chemistries used for the detection of PCR product during real-time PCR, as well as advantages and limitations of real-time PCR will be depicted. Furthermore, the existing literature as it applies to plant pathogens detection in the routine and research laboratory will be reviewed in order to focus on one of the many areas in which the application of real-time PCR has provided significant methodological benefits.     

Novel Mutations Detected in Avirulence Genes Overcoming Tomato Cf Resistance Genes in Isolates of a Japanese Population of Cladosporium fulvum

Leaf mold of tomato is caused by the biotrophic fungus Cladosporium fulvum which complies with the gene-for-gene system. The disease was first reported in Japan in the 1920s and has since been frequently observed. Initially only race 0 isolates were reported, but since the consecutive introduction of resistance genes Cf-2, Cf-4, Cf-5 and Cf-9 new races have evolved. Here we first determined the virulence spectrum of 133 C. fulvum isolates collected from 22 prefectures in Japan, and subsequently sequenced the avirulence (Avr) genes Avr2, Avr4, Avr4E, Avr5 and Avr9 to determine the molecular basis of overcoming Cf genes. Twelve races of C. fulvum with a different virulence spectrum were identified, of which races 9, 2.9, 4.9, 4.5.9 and 4.9.11 occur only in Japan. The Avr genes in many of these races contain unique mutations not observed in races identified elsewhere in the world including (i) frameshift mutations and (ii) transposon insertions in Avr2, (iii) point mutations in Avr4 and Avr4E, and (iv) deletions of Avr4E, Avr5 and Avr9. New races have developed by selection pressure imposed by consecutive introductions of Cf-2, Cf-4, Cf-5 and Cf-9 genes in commercially grown tomato cultivars. Our study shows that molecular variations to adapt to different Cf genes in an isolated C. fulvum population in Japan are novel but overall follow similar patterns as those observed in populations from other parts of the world. Implications for breeding of more durable C. fulvum resistant varieties are discussed.     

Differential interactions among cotton genotypes and isolates of Fusarium oxysporum f. sp. vasinfectum

Abstract

The pathogenicity of nine isolates of Fusarium oxysporum f. sp. vasinfectum (Fov) was evaluated on seedlings of 30 cotton (Gossypium barbadense L.) genotypes in 2005 and 2006. Isolate×genotype interaction was a highly significant (P < 0.01) source of variation in wilt incidence, suggesting that physiologic specialization exists within Fov isolates. Cluster analysis of aggressiveness of isolates and susceptibility of genotypes by the unweighted pair-group method based on arithmetic means (UPGMA) placed the isolates and the genotypes in several groups. Isolates were separated into two distinct groups. One group was closely related to race 5 while the other group was closely related to race 1. Cluster analysis also demonstrated that the Egyptian commercial cultivars had unique susceptibility patterns to Fov isolates remotely related to those of the other genotypes. The interaction between experiments of 2005 and 2006 was mainly due to a differential effect of years on the disease incidence for cotton cultivars.     

Horizontal gene and chromosome transfer in plant pathogenic fungi affecting host range

Plant pathogenic fungi adapt quickly to changing environments including overcoming plant disease resistance genes. This is usually achieved by mutations in single effector genes of the pathogens, enabling them to avoid recognition by the host plant. In addition, horizontal gene transfer (HGT) and horizontal chromosome transfer (HCT) provide a means for pathogens to broaden their host range. Recently, several reports have appeared in the literature on HGT, HCT and hybridization between plant pathogenic fungi that affect their host range, including species of Stagonospora/Pyrenophora, Fusarium and Alternaria. Evidence is given that HGT of the ToxA gene from Stagonospora nodorum to Pyrenophora tritici-repentis enabled the latter fungus to cause a serious disease in wheat. A nonpathogenic Fusarium species can become pathogenic on tomato by HCT of a pathogenicity chromosome from Fusarium oxysporum f.sp lycopersici, a well-known pathogen of tomato. Similarly, Alternaria species can broaden their host range by HCT of a single chromosome carrying a cluster of genes encoding host-specific toxins that enabled them to become pathogenic on new hosts such as apple, Japanese pear, strawberry and tomato, respectively. The mechanisms HGT and HCT and their impact on potential emergence of fungal plant pathogens adapted to new host plants will be discussed.     

Simple and rapid protocol for the isolation of PCR-amplifiable DNA from medicinal plants

Medicinal plant species has a valuable economic importance because of its usage as pharmaceuticals, nutritional, as well as its use in popular medication. For DNA-based techniques, nanogram quantities of the purified DNA are requisite to amplify and yield sufficient amounts of PCR products. SDS-based DNA isolation method was used to extract DNA from 11 species of different aromatic and medicinal plants collected from Saudi Arabia. Three hundred milligrams of fresh shredded plant material was necessary. The DNA purity was further confirmed by agarose gel, restriction endonuclease digestion and microsatellite primed-polymerase chain reaction (MP-PCR). DNA yields ranged from 10-20 μg (in 100-μL elution volumes) from all plant material evaluated. The DNA obtained was free of any contaminating proteins, polysaccharides and colored pigments. The extracted genomic DNA was found suitable for restriction digestion and PCR amplification. Our experimental procedure provides an easy, suitable, non-toxic, cheap, and quick process for the amplification of DNA from medical plant tissue.     

M13-microsatellite PCR and rDNA sequence markers for identification of Trichoderma (Hypocreaceae) species in Saudi Arabian soil

Seven fungal isolates were identified as pan-global Hypocrea/Trichoderma species, from section Trichoderma, on the basis of their morphology. These species were H. lixii/T. harzianum and H. orientalis/T. longibrachiatum. PCR-based markers with primer M13 (core sequence of phage M13) and internal-transcribed spacer sequences of ribosomal DNA were used to confirm the identity of the two Trichoderma species. Sequence identification was performed using the TrichOKEY version 2.0 barcode program and the multilocus similarity search database TrichoBLAST. Sequences from the ribosomal DNA internal-transcribed spacer regions showed limited variation among the Trichoderma species. This analysis divided the isolates into two main groups. Grouping the isolates based on cluster analysis of their DNA profiles matched the grouping based on morphological taxonomy. Molecular data obtained from analyses of gene sequences are essential to distinguish phonetically cryptic species in this group and to establish phylogenetic relationships.