Glucosinolates (GLSs) are a well-known class of specialized plant metabolites, distributed mostly in the order Brassicales. A vast research field in basic and applied sciences has grown up around ...GLSs owing to their presence in important agricultural crops and the model plant
, and their broad range of bioactivities beneficial to human health. The major purpose of GLSs in plants has been considered their function as a chemical defense against predators. GLSs are physically separated from a specialized class of beta-thioglucosidases called myrosinases, at the tissue level or at the single-cell level. They are brought together as a consequence of tissue damage, primarily triggered by herbivores, and their interaction results in the release of toxic volatile chemicals including isothiocyanates. In addition, recent studies have suggested that plants may adopt other strategies independent of tissue disruption for initiating GLS breakdown to cope with certain biotic/abiotic stresses. This hypothesis has been further supported by the discovery of an atypical class of GLS-hydrolyzing enzymes possessing features that are distinct from those of the classical myrosinases. Nevertheless, there is only little information on the physiological importance of atypical myrosinases. In this review, we focus on the broad diversity of the beta-glucosidase subclasses containing known atypical myrosinases in
to discuss the hypothesis that numerous members of these subclasses can hydrolyze GLSs to regulate their diverse functions in plants. Also, the increasingly broadening functional repertoires of known atypical/classical myrosinases are described with reference to recent findings. Assessment of independent insights gained from
with respect to (1) the phenotype of mutants lacking genes in the GLS metabolic/breakdown pathways, (2) fluctuation in GLS contents/metabolism under specific conditions, and (3) the response of plants to exogenous GLSs or their hydrolytic products, will enable us to reconsider the physiological importance of GLS breakdown in particular situations, which is likely to be regulated by specific beta-glucosidases.
Following the sequencing of whole genomes of model plants, high-throughput decoding of gene function is a major challenge in modern plant biology. In view of remarkable technical advances in ...transcriptomics and metabolomics, integrated analysis of these ‘omics’ by data-mining informatics is an excellent tool for prediction and identification of gene function, particularly for genes involved in complicated metabolic pathways. The availability of
Arabidopsis public transcriptome datasets containing data of >1000 microarrays reinforces the potential for prediction of gene function by transcriptome coexpression analysis. Here, we review the strategy of combining transcriptome and metabolome as a powerful technology for studying the functional genomics of model plants and also crop and medicinal plants.
Hypervirulent Klebsiella pneumoniae (hvKp) has been recognized an emerging pathogen that can cause life-threading infections including liver abscess, and endophthalmitis in Eastern Asia. However, ...clinical feature of infective endocarditis (IE) caused by hvKp is still unknown.
Case Description; A 47-year-old male with no past medical history developed 3 days of fever, chills. He was admitted due to altered mental status (GCS E4V4M6), and his blood pressure was 134/91 mmHg, pulse rate was 109 bpm, and body temperature was 101.48°F (38.6°C). A petechiae on the conjunctiva, both palms, and left sole were found. Vegetation with perforation on the mitral valve was found by transthoracic echocardiogram. Blood cultures were negative with no current antimicrobial exposure. Infective endocarditis was confirmed according to modified Duke criteria. Intravenous vancomycin with cefepime was administrated as empiric antimicrobial therapy for blood culture- negative endocarditis (BCNE). A mitral valve replacement was performed according to the mitral valve perforation. The 16S rRNA gene sequence of vegetation from the mitral valve showed Klebsiella pneumoniae. The multi-locus sequence typing (MLST) revealed the sequence type (ST) 23, and virulence genes (rmpA, rpmA2) were also positive for PCR from the vegetation. Following valve replacement, an adenocarcinoma in descending colon was found and a left hemicolectomy was performed.
Several reports showed that hvKp IE was caused by hematogenous spread from other foci such as pyogenic liver abscess. Although colon cancer could be the entry for hvKp for the current case, no abscesses including liver were found. Primary infective endocarditis caused by hvKp is extremely rare but underestimated in the case of BCNE.
This is the first report of blood culture-negative hvKp endocarditis confirmed by 16S rRNA gene sequencing with virulence gene detection from vegetation. In the case of BCNE with rapid progression of unstable hemodynamic status, hvKp should be considered a causable pathogen.
Summary
Plant secondary metabolites are known to facilitate interactions with a variety of beneficial and detrimental organisms, yet the contribution of specific metabolites to interactions with ...fungal pathogens is poorly understood. Here we show that, with respect to aliphatic glucosinolate‐derived isothiocyanates, toxicity against the pathogenic ascomycete Sclerotinia sclerotiorum depends on side chain structure. Genes associated with the formation of the secondary metabolites camalexin and glucosinolate were induced in Arabidopsis thaliana leaves challenged with the necrotrophic pathogen S. sclerotiorum. Unlike S. sclerotiorum, the closely related ascomycete Botrytis cinerea was not identified to induce genes associated with aliphatic glucosinolate biosynthesis in pathogen‐challenged leaves. Mutant plant lines deficient in camalexin, indole, or aliphatic glucosinolate biosynthesis were hypersusceptible to S. sclerotiorum, among them the myb28 mutant, which has a regulatory defect resulting in decreased production of long‐chained aliphatic glucosinolates. The antimicrobial activity of aliphatic glucosinolate‐derived isothiocyanates was dependent on side chain elongation and modification, with 8‐methylsulfinyloctyl isothiocyanate being most toxic to S. sclerotiorum. This information is important for microbial associations with cruciferous host plants and for metabolic engineering of pathogen defenses in cruciferous plants that produce short‐chained aliphatic glucosinolates.
Ni anisotropic microgroove structures were prepared by lithographic processes and electroforming to investigate the effect of microstructures on friction forces. For Ni microgroove structures, the ...friction forces varied significantly depending on the indenter sliding direction to the anisotropic microstructures. The friction forces of parallel sliding directions on microgroove structures were unstable and considerably larger than those of the perpendicular directions owing to the difference in the structure continuousness. These results suggest that anisotropic microstructures affect friction forces and can deploy fail-safe functions when a large load is accidentally applied.
Background: Metronidazole (MNZ) is a widely used antibiotic against anaerobic and parasitic infections due to its efficiency and safety with penetration to the central nervous system (CNS). ...MNZ-induced encephalopathy (MIE) is recognized as a rare adverse event.
Case description of a 40-year-old-man, with depression, presented with altered mental status and agitation for past two days before hospitalization. The patient found to have aphasia on examination. No meningeal sign found. Blood culture taken at admission was negative. However multiple brain abscess was found in magnetic resonance imaging (MRI). Intravenous MNZ (500mg TID) combined with vancomycin (1.5g BID) and ceftriaxone (2g BID) were administered empirically for 6 weeks as bacterial brain abscess. No pathogen was also identified from fluid by drainage. Antimicrobial treatment was switched to oral MNZ with Sulfamethoxazole-Trimethoprim for 4 weeks. During the followup, the patient developed dizziness and physical examination showed symptoms of cerebella ataxia. MIE was confirmed according to symmetrical hyperintensity in the dentate nuclei of cerebellum on both T2 and FLAIR image as a ‘boomerang-sign’ on brain MRI. The symptom was improved within 2 weeks followed by discontinuation of oral MNZ. One month later, MRI showed complete resolution of the MIE features as well as diminishing of brain abscess. Amount dose of MNZ administered was 105g.
Summary
Background
Epstein‐Barr virus (EBV)‐associated T/natural‐killer lymphoproliferative disorders form a group of diseases that includes classical and systemic hydroa vacciniforme (HV) and ...hypersensitivity to mosquito bites (HMB). Patients with systemic HV (sHV) and HMB often have a poor prognosis, although little is known about the prognostic factors.
Objectives
To elucidate the prognostic factors of HV and HMB.
Methods
We studied clinicopathological manifestations, routine laboratory findings, anti‐EBV titres, EBV DNA load and EBV‐encoded gene expression, including expression of BZLF1, in 50 patients with classical HV (cHV), sHV, HMB only and HMB with HV (HMB + HV), and further analysed 30 patients who were available for follow‐up.
Results
The median age of disease onset was 5 years (range 1–74). A follow‐up study indicated that fatal outcomes were observed in three of eight patients with sHV, two of six patients with HMB only, and two of five patients with HMB + HV. The main causes of death were complications from haematopoietic stem‐cell transplantation and multiorgan failure. There were no fatalities among the 11 patients with cHV. Univariate analysis revealed two poor prognostic indicators: (i) onset age > 9 years and (ii) the expression of an EBV‐encoded immediate–early gene transcript, BZLF1 mRNA, in the skin lesions (P < 0·001 and P = 0·003, respectively).
Conclusions
No prognostic correlation was observed in EBV‐infected lymphocyte subsets, anti‐EBV antibody titres or EBV DNA load. Late onset and EBV reactivation are both related to more severe phenotypes of the disease, and thus may predict a poor prognosis.
What's already known about this topic?
Epstein–Barr virus‐associated T/natural‐killer lymphoproliferative disorders form a group of diseases that includes classical and systemic hydroa vacciniforme (HV), and hypersensitivity to mosquito bites (HMB).
Patients with systemic HV and HMB usually present with fever, liver damage and haematological abnormalities, and often have a fatal outcome.
What does this study add?
Our patients with classical HV showed a favourable prognosis, while approximately one‐third of the patients with systemic HV or HMB died during the 10‐year follow‐up.
Late onset (over 9 years of age) and an EBV reactivation signal (BZLF1 mRNA expression) were both related to more severe phenotypes of the disease, and a poor prognosis.
This study evaluated the association between skeletal muscle mass depletion and severe oral mucositis in patients undergoing concurrent chemoradiotherapy after oral cancer resection. Skeletal muscle ...mass was evaluated in 60 patients using the skeletal muscle index, which was based on skeletal muscle cross-sectional area (on computed tomography) at the level of the third lumbar vertebra. In accordance with the grading criteria of the Radiation Therapy Oncology Group, patients with a grade ≥3 were defined as having severe oral mucositis. Multivariate logistic regression analysis was used to evaluate independent risk factors for severe oral mucositis. Eleven patients (18.3%) were diagnosed with low skeletal muscle mass. Severe oral mucositis occurred in 17 (28.3%) patients, and the mean skeletal muscle index was 42.8 cm2/m2. A low skeletal muscle mass (hazard ratio 18.1; P=0.001) and a chemotherapy regimen consisting of 5-fluorouracil and cisplatin (versus cisplatin only) (hazard ratio 5.5; P=0.015) were independent risk factors for severe oral mucositis. Future prospective studies are warranted to identify effective pre- and perioperative exercises and nutrition programmes to increase low skeletal muscle mass and reduce the incidence of severe oral mucositis in patients undergoing concurrent chemoradiotherapy after oral cancer resection.
The regulation of intracellular pyrophosphate (PPi) level is crucial for proper morphogenesis across all taxonomic kingdoms. PPi is released as a byproduct from ~200 metabolic reactions, then ...hydrolyzed by either membrane-bound (H
-PPase) or soluble pyrophosphatases (PPases). In Arabidopsis, the loss of the vacuolar H
-PPase/FUGU5, a key enzyme in PPi homeostasis, results in delayed growth and a number of developmental defects, pointing to the importance of PPi homeostasis in plant morphogenesis. The Arabidopsis genome encodes several PPases in addition to FUGU5, such as PPsPase1/PECP2, VHP2;1 and VHP2;2, although their significance regarding PPi homeostasis remains elusive. Here, to assess their contribution, phenotypic analyses of cotyledon aspect ratio, palisade tissue cellular phenotypes, adaxial side pavement cell complexity, stomatal distribution, and etiolated seedling length were performed, provided that they were altered due to excess PPi in a
mutant background. Overall, our analyses revealed that the above five traits were unaffected in
,
and
loss-of-function mutants, as well as in
mutant lines constitutively overexpressing
. Furthermore, metabolomics revealed that
,
and
etiolated seedlings exhibited metabolic profiles comparable to the wild type. Together, these results indicate that the contribution of PPsPase1/PECP2, VHP2;1 and VHP2;2 to PPi levels is negligible in comparison to FUGU5 in the early stages of seedling development.
Plants possess many metabolic genes for the production of a wide variety of phytochemicals in a tissue-specific manner. However, the metabolic systems behind the diversity and tissue-dependent ...regulation still remain unknown due to incomplete characterization of phytochemicals produced in a single plant species. Thus, having a metabolome dataset in addition to the genome and transcriptome information resources would enrich our knowledge of plant secondary metabolism. Here we analyzed phytochemical accumulation during development of the model plant Arabidopsis (Arabidopsis thaliana) using liquid chromatography-mass spectrometry in samples covering many growth stages and organs. We also obtained tandem mass spectrometry spectral tags of many metabolites as a resource for elucidation of metabolite structure. These are part of the AtMetExpress metabolite accumulation atlas. Based on the dataset, we detected 1,589 metabolite signals from which the structures of 167 metabolites were elucidated. The integrated analyses with transcriptome data demonstrated that Arabidopsis produces various phytochemicals in a highly tissue-specific manner, which often accompanies the expression of key biosynthesis-related genes. We also found that a set of biosynthesis-related genes is coordinately expressed among the tissues. These data suggested that the simple mode of regulation, transcript to metabolite, is an origin of the dynamics and diversity of plant secondary metabolism.
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