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83.
Shazia Parveen Foziya Altaf Sumira Farooq Aehsan ul Haq Mohammad Lateef Lone Inayatullah Tahir 《Physiology and Molecular Biology of Plants》2021,27(7):1597
The present investigation primarily focussed on evaluating the efficacy of exogenous proline on the flower longevity of Dianthus chinensis L. Floral buds were harvested at the paint brush stage (i.e., a day prior to anthesis) and divided into 6 sets, with one set of buds (i.e., control) held in distilled water and rest of the 5 sets were supplemented with various concentrations of proline, viz., 10 mM, 20 mM, 30 mM, 40 mM and 50 mM. The application of proline at 40 mM concentration proved out to be most effective in improving the longevity of the flowers by about 4 days as compared to the control. The ameliorated longevity coincided with enhanced floral diameter, fresh mass, dry mass and water content. The flowers with delayed senescence also maintained higher soluble proteins, sugars and phenols. The results suggest that exogenous proline effectively alleviates oxidative stress in the petal tissue, as evident by a relatively lower maloendialdehyde content, which is manifested in the form of reduced lipid peroxidation (LPO). Reduced LPO was commensurate with increased membrane stability, quantified by membrane stability index. Moreover, the flowers with improved longevity exhibited a decline in lipoxygenase activity and significant augmentation of antioxidant enzymes superoxide dismutase, catalase and ascorbate peroxidase. 相似文献
84.
Sortilin and SorLA are members of the Vps10p domain receptor family, the Sortilins, which comprise five type I transmembrane
receptors differentially expressed in neuronal tissues of the central and peripheral nervous system. Since the identification
of sortilin in 1997, members of this receptor family are recognized as sorting receptors primarily in the trans-Golgi network,
interacting with a wide range of ligands comprising other transmembrane receptors as well as soluble proteins from neurotrophic
factors to enzymes targeted for lysosomes. Specifically, the involvement of sortilin in neutrophin signaling in healthy and
injured neurons is increasingly recognized, as well as the impact of SorLA on the cellular processing of amyloid precursor
protein, an important component in Alzheimer’s disease. The current understanding of these issues as well as the recent recognition
of a molecular link between sortilin and frontotemporal dementia is addressed in this present review. 相似文献
85.
Hansen BG Mnich E Nielsen KF Nielsen JB Nielsen MT Mortensen UH Larsen TO Patil KR 《Applied and environmental microbiology》2012,78(14):4908-4913
Mycophenolic acid (MPA) is a fungal secondary metabolite and the active component in several immunosuppressive pharmaceuticals. The gene cluster coding for the MPA biosynthetic pathway has recently been discovered in Penicillium brevicompactum, demonstrating that the first step is catalyzed by MpaC, a polyketide synthase producing 5-methylorsellinic acid (5-MOA). However, the biochemical role of the enzymes encoded by the remaining genes in the MPA gene cluster is still unknown. Based on bioinformatic analysis of the MPA gene cluster, we hypothesized that the step following 5-MOA production in the pathway is carried out by a natural fusion enzyme MpaDE, consisting of a cytochrome P450 (MpaD) in the N-terminal region and a hydrolase (MpaE) in the C-terminal region. We verified that the fusion gene is indeed expressed in P. brevicompactum by obtaining full-length sequence of the mpaDE cDNA prepared from the extracted RNA. Heterologous coexpression of mpaC and the fusion gene mpaDE in the MPA-nonproducer Aspergillus nidulans resulted in the production of 5,7-dihydroxy-4-methylphthalide (DHMP), the second intermediate in MPA biosynthesis. Analysis of the strain coexpressing mpaC and the mpaD part of mpaDE shows that the P450 catalyzes hydroxylation of 5-MOA to 4,6-dihydroxy-2-(hydroxymethyl)-3-methylbenzoic acid (DHMB). DHMB is then converted to DHMP, and our results suggest that the hydrolase domain aids this second step by acting as a lactone synthase that catalyzes the ring closure. Overall, the chimeric enzyme MpaDE provides insight into the genetic organization of the MPA biosynthesis pathway. 相似文献
86.
Svenningsen NB Heisterkamp IM Sigby-Clausen M Larsen LH Nielsen LP Stief P Schramm A 《Applied and environmental microbiology》2012,78(12):4505-4509
Nitrification in shell biofilms and denitrification in the gut of the animal accounted for N(2)O emission by Dreissena polymorpha (Bivalvia), as shown by gas chromatography and gene expression analysis. The mussel's ammonium excretion was sufficient to sustain N(2)O production and thus potentially uncouples invertebrate N(2)O production from environmental N concentrations. 相似文献
87.
Pitzer VE Burgner D Viboud C Simonsen L Andreasen V Steiner CA Lipsitch M 《Proceedings. Biological sciences / The Royal Society》2012,279(1739):2736-2743
The average age of infection is expected to vary during seasonal epidemics in a way that is predictable from the epidemiological features, such as the duration of infectiousness and the nature of population mixing. However, it is not known whether such changes can be detected and verified using routinely collected data. We examined the correlation between the weekly number and average age of cases using data on pre-vaccination measles and rotavirus. We show that age-incidence patterns can be observed and predicted for these childhood infections. Incorporating additional information about important features of the transmission dynamics improves the correspondence between model predictions and empirical data. We then explored whether knowledge of the age-incidence pattern can shed light on the epidemiological features of diseases of unknown aetiology, such as Kawasaki disease (KD). Our results indicate KD is unlikely to be triggered by a single acute immunizing infection, but is consistent with an infection of longer duration, a non-immunizing infection or co-infection with an acute agent and one with longer duration. Age-incidence patterns can lend insight into important epidemiological features of infections, providing information on transmission-relevant population mixing for known infections and clues about the aetiology of complex paediatric diseases. 相似文献
88.
Amy N. Spiegel E. Margaret Evans Brandy Frazier Ashley Hazel Medha Tare Wendy Gram Judy Diamond 《Evolution》2012,5(1):43-61
We examined whether a single visit to an evolution exhibition contributed to conceptual change in adult (n?=?30), youth, and child (n?=?34) museum visitors?? reasoning about evolution. The exhibition included seven current research projects in evolutionary science, each focused on a different organism. To frame this study, we integrated a developmental model of visitors?? understanding of evolution, which incorporates visitors?? intuitive beliefs, with a model of free-choice learning that includes personal, sociocultural, and contextual variables. Using pre- and post-measures, we assessed how visitors?? causal explanations about biological change, drawn from three reasoning patterns (evolutionary, intuitive, and creationist), were modified as a result of visiting the exhibition. Whatever their age, background beliefs, or prior intuitive reasoning patterns, visitors significantly increased their use of explanations from the evolutionary reasoning pattern across all measures and extended this reasoning across diverse organisms. Visitors also increased their use of one intuitive reasoning pattern, need-based (goal-directed) explanations, which, we argue, may be a step toward evolutionary reasoning. Nonetheless, visitors continued to use mixed reasoning (endorsing all three reasoning patterns) in explaining biological change. The personal, socio-cultural, and contextual variables were found to be related to these reasoning patterns in predictable ways. These findings are used to examine the structure of visitors?? reasoning patterns and those aspects of the exhibition that may have contributed to the gains in museum visitors?? understanding of evolution. 相似文献
89.
Fuursted K Schøler L Hansen F Dam K Bojer MS Hammerum AM Dagnæs-Hansen F Olsen A Jasemian Y Struve C 《Microbes and infection / Institut Pasteur》2012,14(2):155-158
The aim of the study was to compare and evaluate virulence in five strains of Klebsiella pneumoniae, including an isolate carrying New Delhi metallo-beta-lactamase-1 (NDM-1). In vivo virulence was assessed using a murine sepsis model and using the nematode Caenorhabditis elegans killing model, and in vitro virulence by assessing various virulence factors. The NDM-1 carrying K. pneumoniae isolate was the most virulent in the murine sepsis model but there was no clear cut correlation to in vitro virulence factors or killing in C. elegans. It is concluded that K. pneumoniae carrying NDM-1 have an intrinsic virulence potential, which in coexistence with its multiresistance could promote and partly explain its epidemiological success. 相似文献
90.
Ahlehoff O Skov L Gislason G Lindhardsen J Kristensen SL Iversen L Lasthein S Gniadecki R Dam TN Torp-Pedersen C Hansen PR 《PloS one》2012,7(4):e36342