Powdery mildew (Blumeria graminis f. sp. tritici) is one of the most devastating wheat diseases. The wheat line N9134 contains PmAS846 that was transferred to N9134 from wild emmer wheat, and is still one of the most effective resistance genes in China. A full-length wheat RPM1 gene was obtained by rapid amplification of cDNA ends (RACE) based on the up-regulated probe sequence from differentially expressed transcripts during the N9134 and powdery mildew interaction. The gene was named TaRPM1, and the open reading frame (ORF) is 2721 nucleotides and encodes a polypeptide of 907 amino acids with a predicted isoelectric point of 4.86. Phylogenetic analysis revealed that TaRPM1 was highly homologous on both Aegilops tauschii and Triticum urartu at both the nucleotide and protein level. Using real-time quantitative PCR, the TaRPM1 gene expression level in wheat leaves was found to be sharply up-regulated, while the transcript level was lowly induced in the root and stem. Under the powdery mildew treatment, the transcription profile of TaRPM1 was very strongly expressed at 48 hour post inoculation (hpi), which increased again to 96 hpi and reaching a high level at 120 hpi. Based on sequence similarities and positions, we inferred that the TaRPM1 gene was on wheat chromosome 3D. These results suggested that TaRPM1 plays an important role in the mechanism of innate immunity to infection by the powdery mildew pathogen.
Authors:Ralf Ignatius, Robert Neuber, Heike Kietzmann, Christiane Berg, Thilo Wenzel, Jörg Fuhrmann, and Michael Müller
This study aimed at evaluating in outpatients an algorithm for the laboratory diagnosis of Clostridioides (Clostridium) difficile infection (CDI), i.e., enzyme immunoassays (EIAs) detecting bacterial glutamate dehydrogenase (GDH) and toxin A/B, followed by polymerase chain reaction (PCR) analyses of samples with discordant EIA results.
In total, 9802 examinations of stool samples by GDH and toxin EIAs performed in 7263 outpatients and 488 inpatients were analyzed retrospectively. Samples with discordant EIA results had been tested by a commercially available PCR assay detecting genes of the C. difficile-specific triose phosphate isomerase (tpi) and toxin B (tcdB).
Concordant EIA results (686 C. difficile-positive, 8121 negative) were observed for 8807 (89.8%; 95% CI, 89.2–90.4%) samples. Of 958 samples with discordant EIA results, 895 were analyzed using PCR and 580 of 854 GDH-positive/borderline, toxin-negative samples (67.9%; 95% CI, 64.7–71.0%) were positive for tpi and tcdB, while 274 samples (32.1%; 95% CI, 29.0–35.3%) were tcdB-negative. In contrast, 35 of 41 GDH-negative, toxin-positive/borderline samples (85.4%; 95% CI, 71.2–93.5%) were tcdB-negative. Still, 6 samples (14.6%; 95% CI, 6.5–28.8%) yielded positive PCR results for both genes.
In conclusion, around 90% of the samples were analyzed appropriately by only applying EIAs. Approximately one third of the PCR-analyzed samples were tcdB-negative; thus, patients most likely did not require CDI treatment.
Authors:J. Sangrattanaprasert, S. Kornochaleart, and S. Chantanaorrapint
Cololejeunea metzgeriopsis (K. I. Goebel) Gradst. et al., a neotenic liverwort, was newly discovered in lowland evergreen forest, southern Thailand. A description and illustrations of Thai plants are provided.
Authors:S. Esfandani-Bozchaloyi, M. Sheidai, and M. Hassanzadeh Kalalegh
The genus Geranium (Geraniaceae); with about 320 species throughout the temperate regions, is chemically characterised by the presence of tannins, flavonoids, anthocyanins and essential oils which interfere with the extraction of pure genomic DNA. It is necessary to optimise the extraction protocols to reduce the effects of the presence of these compounds to the lowest level.
The present study compares the plant genomic DNA extraction Kit (DNP™ Kit), CTAB DNA extraction method by Murray and Thompson and Sahu et al., from the extracting DNA point of view Geranium species. The results showed significant differences in DNA contents between the three methods. Quantity and quality of extracted genomic DNAs were compared by employing the spectrophotometer, Nano-Drop, agarose gel electrophoresis, and polymerase chain reaction (PCR) methods and molecular marker such as (ITS and trnL-F) and ISSR. The method of Sahu et al., provided the best results (200 ng/µL) in terms of quantity and quality of DNA, therefore, this method was taken and optimised for DNA extraction. Our results proposed that this method could be effective for plants with same polysaccharides, proteins and polyphenols components. The advantage of this method is that it omits the use of liquid nitrogen and toxic phenols which are expensive. The success of this method in obtaining high-quality genomic DNA has been demonstrated in the Geranium species group and the reliability of this method has been discussed.
Authors:M.I.E. Arabi, E. Al-shehadah, and M. Jawhar
Powdery mildew, caused by Blumeria graminis f. sp. hordei (Bgh) is a common foliar disease of barley worldwide. The creation of new cultivars with durable resistance to Bgh is highly desirable. This work was undertaken to examine the resistance to Bgh in 10 genetically diverse barley parents, and to evaluate their general combining ability (GCA) and specific combining ability (SCA) effects toward determining the genetic basis of disease resistance. Two experiments, in a growth chamber on seedling and in the field on adult plant stages, were conducted using a randomized complete block design with three replicates. The parents expressing differences in their reactions to Bgh were crossed in a half-diallel mating design to generate 45 full-sib families. Genetic component analysis showed significant effects for both GCA and SCA under both experiments suggesting that additive as well as non-additive genetic mechanisms were involved in the expression of resistance in these parents. The estimate of narrow-sense heritability was 0.63 and broad-sense heritability was 98% indicating that selection for the disease resistance should be effective in these crosses. Resistant parents ‘Banteng, PK 30-136 and ‘Igri’ had significantly negative GCA effects, suggesting their prime suitability for use in barley breeding programs to improve resistance to Bgh.
Authors:Katrin Bote, Judith Pöppe, Susanne Riede, Gerhard Breves, and Uwe Roesler
Glyphosate (N-(phosphonomethyl)glycine) is the most-used herbicide worldwide. Many studies in the past have shown that residues of the herbicide can be found in many cultivated plants, including those used as livestock feed. Sensitivity to glyphosate varies with bacteria, particularly those residing in the intestine, where microbiota is exposed to glyphosate residues. Therefore, less susceptible pathogenic isolates could have a distinct advantage compared to more sensitive commensal isolates, probably leading to dysbiosis.
To determine whether the ruminal growth and survival of pathogenic Escherichia coli or Salmonella serovar Typhimurium are higher when glyphosate residues are present in the feed, an in vitro fermentation trial with a “Rumen Simulation System” (RUSITEC) and a glyphosate-containing commercial formulation was performed.
Colony forming units of E. coli and Salmonella ser. Typhimurium decreased steadily in all fermenters, regardless of the herbicide application. Minimum inhibitory concentrations of the studied Salmonella and E. coli strains did not change, and antibiotic susceptibility varied only slightly but independent of the glyphosate application.
Overall, application of the glyphosate-containing formulation in a worst-case concentration of 10 mg/L neither increased the abundance for the tested E. coli and Salmonella strain in the in vitro fermentation system, nor promoted resistance to glyphosate or antibiotics.
Authors:Rafighe Ghiasi, Roya Naderi, Asou Mozaffar, and Alireza Alihemmati
Elevated oxidative stress in type 2 diabetes mellitus (T2DM) has been proposed as one of the major risk factors in pathophysiology of several organ damages including liver tissue.
Materials and methods
In this study, we evaluated the effect of swimming training on hepatic oxidative markers, SIRT1 gene expression, and histological alterations in T2DM. Twenty-eight male Wistar rats were randomly assigned into four groups (N = 7): control, exercise, diabetic, and diabetic + exercise. One week after the induction of T2DM, rats were subjected to swimming (60 min/5 days a week) for 12 weeks. At the end of the experiment, oxidative markers (SOD, GPx, CAT activities, and MDA level) and SIRT1 gene expression were measured in the liver by special kits and RT-PCR, respectively. Hematoxylin–eosin statins were used for histological alterations.
Swimming training attenuated MDA levels and enhanced SOD, GPx, and CAT activities in the liver of diabetic animals. Furthermore, swimming training restored the expression of SIRT1 in T2DM. Histopathological finding of the hepatic tissue confirmed a protective role for swimming training in diabetic rats.
Our findings indicate that swimming training attenuates oxidative stress probably by upregulation of SIRT1 in the liver of type 2 diabetic rats.
Authors:R. Liu, Q.N. Zhang, J. Lu, C.H. Zhang, L. Zhang, and Y. Wu
Salt stress is one of the major abiotic stress which severely limits plant growth and reduces crop productivity across the world. In the present study, the effects of exogenous pyridoxal-5-phosphate (vitamin B6, VB6) on seedling growth and development of wheat under salt stress were investigated. The results showed that exogenous application of pyridoxal-5-phosphate (VB6) significantly increased the RWC, biomass, the concentration of photosynthetic pigments, proline, the activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), together with decreasing the content of Malondiadehyde (MDA) and hydrogen peroxide (H2O2) in wheat leaves under salt stress. Meanwhile, the transcript level of P5CR, P5CS, SOD, TaSOS1 and TaSOS4 were also up-regulated after treatment with pyridoxal-5-phosphate. VB6 acts as a signal in regulating the activities of plant antioxidant enzymes and SOS pathway to improve resistance to salt stress. The current study results may give an insight into the regulatory roles of VB6 in improving salt stress and VB6 could be an easily and effective method to improve salt-stress tolerance to wheat in the field condition. It is urgency to understand the molecular mechanism of VB6 to enhance the salt tolerance of wheat in the next work.
Authors:Arne Thell, Mats Hansson, Per-Erik Persson, Mark R. D. Seaward, Maik Veste, and Mikael Hedrén
Background and aims
Betony (Betonica officinalis L.) is one of the rarest and most spectacular plants in the Scandinavian flora. A long-term question has been whether it is spontaneous or introduced, or whether it comprises both spontaneous and introduced populations. This study aimed to answer this question by analyzing sequence data from the nuclear external transcribed spacer (ETS) region and three regions of the plastid genome, the trnT–trnL intergenic spacer (IGS) region, tRNA-Leu (trnL) intron, and the trnS–trnG IGS.
Materials and methods
Altogether 41 samples from 11 European countries were analyzed. A unique duplication in the trnT–trnL IGS was detected in material from Skåne (southern Sweden), the “Skåne-duplication.” Populations with this duplication are united on a moderately supported branch in the phylogeny based on plastid sequences. A distinct heath genotype from Yorkshire was discovered in the phylogeny based on plastid sequences and in a comparative cultivation.
Phylogeny based on ETS sequences does not support any Scandinavian group, whereas a principal coordinates analysis ordination based on variable ETS positions indicated a spontaneous origin for all Scandinavian populations, which comprise a genetically well-defined subgroup of the species, most closely related to other spontaneous populations from adjacent parts of continental parts of northern Europe.
Seven possible naturally occurring localities remain in Scandinavia, five in central Skåne, southernmost Sweden, and two on the southwestern part of the Danish island of Lolland.
Authors:A. Sattar, M.A. Cheema, A. Sher, T. Abbas, M. Ijaz, S. Ul-Allah, M. Butt, A. Qayyum, and M. Hussain
The impact of trinexapac-ethyl (TE) on salinity subjected wheat plants was evaluated via pot based experiment. The treatments applied to wheat seedlings included (Ck) control (no NaCl nor TE spray), foliar spray of TE (1.95 ml L−1), only NaCl (50 mM) and NaCl+ TE (50 mM + 1.95 ml L−1). Foliar application of TE was done seven days after imposition of salinity. Growth parameters (root length, shoot length, fresh weight, and dry weight) and photosynthetic pigments content (chlorophyll a, b, a + b and a/b), water relation (water potential, osmotic potential, turgor potential and relative water contents) as well as catalase (CAT) activity exhibited marked reduction in comparison to control. In addition, an increment was noted in organic solutes content (proline, soluble protein and soluble sugar) and enzyme activity of superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) in stressed seedlings over control seedlings. The foliar applied TE mostly enhanced growth of salt stressed seedlings, accompanied by reinforcement in photosynthetic pigments, organic solutes, and enzyme activity (SOD, CAT, POD, and APX) in comparison to stressed seedlings. It is worthy to mention that, TE has potential to enhance salt tolerance of wheat seedlings. Thus, our findings suggest that seedling treated with TE is an effective strategy that can be used to enhance salt tolerance of wheat crop.