排序方式: 共有52条查询结果,搜索用时 15 毫秒
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Benjamin Schwessinger Ofir Bahar Nicolas Thomas Nicolas Holton Vladimir Nekrasov Deling Ruan Patrick E. Canlas Arsalan Daudi Christopher J. Petzold Vasanth R. Singan Rita Kuo Mansi Chovatia Christopher Daum Joshua L. Heazlewood Cyril Zipfel Pamela C. Ronald 《PLoS pathogens》2015,11(3)
Plant plasma membrane localized pattern recognition receptors (PRRs) detect extracellular pathogen-associated molecules. PRRs such as Arabidopsis EFR and rice XA21 are taxonomically restricted and are absent from most plant genomes. Here we show that rice plants expressing EFR or the chimeric receptor EFR::XA21, containing the EFR ectodomain and the XA21 intracellular domain, sense both Escherichia coli- and Xanthomonas oryzae pv. oryzae (Xoo)-derived elf18 peptides at sub-nanomolar concentrations. Treatment of EFR and EFR::XA21 rice leaf tissue with elf18 leads to MAP kinase activation, reactive oxygen production and defense gene expression. Although expression of EFR does not lead to robust enhanced resistance to fully virulent Xoo isolates, it does lead to quantitatively enhanced resistance to weakly virulent Xoo isolates. EFR interacts with OsSERK2 and the XA21 binding protein 24 (XB24), two key components of the rice XA21-mediated immune response. Rice-EFR plants silenced for OsSERK2, or overexpressing rice XB24 are compromised in elf18-induced reactive oxygen production and defense gene expression indicating that these proteins are also important for EFR-mediated signaling in transgenic rice. Taken together, our results demonstrate the potential feasibility of enhancing disease resistance in rice and possibly other monocotyledonous crop species by expression of dicotyledonous PRRs. Our results also suggest that Arabidopsis EFR utilizes at least a subset of the known endogenous rice XA21 signaling components. 相似文献
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Krista L. Plett Annegret Kohler Teresa Lebel Vasanth R. Singan Diane Bauer Guifen He Vivian Ng Igor V. Grigoriev Francis Martin Jonathan M. Plett Ian C. Anderson 《Environmental microbiology》2021,23(4):2004-2020
Ectomycorrhizal (ECM) fungi are integral to boreal and temperate forest ecosystem functioning and nutrient cycling. ECM fungi, however, originate from diverse saprotrophic lineages and the impacts of genetic variation across species, and especially within a given ECM species, on function and interactions with the environment is not well understood. Here, we explore the extent of intra-species variation between four isolates of the ECM fungus Pisolithus microcarpus, in terms of gene regulation, carbon metabolism and growth, and interactions with a host, Eucalyptus grandis. We demonstrate that, while a core response to the host is maintained by all of the isolates tested, they have distinct patterns of gene expression and carbon metabolism, resulting in the differential expression of isolate-specific response pathways in the host plant. Together, these results highlight the importance of using a wider range of individuals within a species to understand the broader ecological roles of ECM fungi and their host interactions. 相似文献
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VB Srinivasan M Venkataramaiah A Mondal V Vaidyanathan T Govil G Rajamohan 《PloS one》2012,7(7):e41505
Background
The diffusion of antibiotics through the outer membrane is primarily affected by the porin super family, changes contribute to antibiotic resistance. Recently we demonstrated that the CpxAR two-component signaling system alters the expression of an uncharacterized porin OmpCKP, to mediate antimicrobial resistance in K. pneumoniae.Principal Findings
In this study, functional characterization of the putative porin OmpCKP (denoted kpnO) with respect to antimicrobial susceptibility and virulence was evaluated by generating an isogenic mutant, ΔkpnO in a clinical isolate of K. pneumoniae. Estimation of uronic acid content confirmed that ΔkpnO produced ∼2.0 fold lesser capsular polysaccharide than the wild-type. The ΔkpnO displayed higher sensitivity to hyper osmotic and bile conditions. Disruption of kpnO increased the susceptibility of K. pneumoniae to oxidative and nitrostative stress by ∼1.6 fold and >7 fold respectively. The loss of the Klebsiella porin led to an increase in the minimum inhibitory concentration of tetracycline (3-fold), nalidixic acid (4-fold), tobramycin (4-fold), streptomycin (10-fold), and spectinomycin (10-fold), which could be restored following complementation. The single deletion of kpnO reduced the survival of the pathogen by 50% when exposed to disinfectants. In Caenorhabditis elegans model, the kpnO mutant exhibited significantly (P<0.01) lower virulence. To dissect the role of PhoBR signaling system in regulating the expression of the kpnO, a phoB KP isogenic mutant was constructed. The phoB KP mutant exhibited impaired gastrointestinal stress response and decreased antimicrobial susceptibility. The mRNA levels of kpnO were found to be 4-fold less in phoB KP mutant compared to wild type. A regulatory role of PhoBKP for the expression of kpnO was further supported by the specific binding of PhoBKP to the putative promoter of kpnO.Conclusions and Significance
Loss of PhoBR regulated porin KpnO resulted in increased antimicrobial resistance, increased susceptibility to gastrointestinal stress, and reduced virulence in K. pneumoniae NTUH-K2044. 相似文献26.
Mysore Gopal Tejeswini Hebbale Vasanth Sowmya Shimoga Prabhakar Swarnalatha 《Archives Of Phytopathology And Plant Protection》2013,46(5):564-570
Natural additives are in demand for the control of microbial growth in foods. Several natural compounds including essential oils (EOs) are being explored for food uses. In the present investigation, the antifungal activity of cinnamaldehyde, eugenol, peppermint and clove EOs and their combinations was evaluated against 12 species of Aspergillus, Fusarium, Penicillium and Rhizopus in in vitro and tomato fruit system (in-vivo). The EOs were able to inhibit complete growth of tested fungi at or below 0.6% level and 80?μL of EOs (except peppermint oil) in in vitro condition and tomato system, respectively. The fractional inhibitory studies showed either additive or indifferent effect by combining eugenol and peppermint, and indifferent or antagonist effect by combining the cinnamaldehyde and clove in both in vitro and in vivo studies. The findings may be useful for application of these EOs in foods, but their effects on organoleptic quality of foods need to be investigated. 相似文献
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Anther-derived pre-embryogenic masses (PEMs) of callus, established via suspension cultures, were encapsulated to form synthetic seeds suitable for cryopreservation. The synchronised suspension
culture proliferation necessitated the optimisation of plant growth regulators for different cultivars. The growth phase and
density of the culture were also important as well as the exposure of cells to vitrification solution containing 0.75 M sucrose
with 0.1 M CaCl2 and 2.0 % sodium alginate (pH 5.7). Pre-treatment of the encapsulated cells for 2 d with Nitsch and Nitsch (NN) medium containing
0.75 M sucrose solution followed by dehydration for 4 h in a laminar flow box provided maximum cell viability, which varied
from 0 to 40 %. The embryo proliferation from the cryopreserved beads involved warming them and then transfer to NN medium
containing glutamine (50 mg dm−3) and activated charcoal (2.5 %). The maximum number of embryos obtained was 31–53 per bead. Subculture into the same medium
induced secondary embryogenesis, which was initiated from the meristematic region, radicle, and root cap. Proliferation and
maturation of secondary embryos was faster than of primary embryos. No phenotypic variation or abnormal structures compared
to the control were observed in the regenerated plantlets. 相似文献
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Claudia?M.B. Carvalho Shivakumar Vasanth Marwan Shinawi Chad Russell Melissa?B. Ramocki Chester?W. Brown Jesper Graakjaer Anne-Bine Skytte Angela?M. Vianna-Morgante Ana?C.V. Krepischi Gayle?S. Patel LaDonna Immken Kyrieckos Aleck Cynthia Lim Sau?Wai Cheung Carla Rosenberg Nicholas Katsanis James?R. Lupski 《American journal of human genetics》2014,95(5):565-578
The 17p13.1 microdeletion syndrome is a recently described genomic disorder with a core clinical phenotype of intellectual disability, poor to absent speech, dysmorphic features, and a constellation of more variable clinical features, most prominently microcephaly. We identified five subjects with copy-number variants (CNVs) on 17p13.1 for whom we performed detailed clinical and molecular studies. Breakpoint mapping and retrospective analysis of published cases refined the smallest region of overlap (SRO) for microcephaly to a genomic interval containing nine genes. Dissection of this phenotype in zebrafish embryos revealed a complex genetic architecture: dosage perturbation of four genes (ASGR1, ACADVL, DVL2, and GABARAP) impeded neurodevelopment and decreased dosage of the same loci caused a reduced mitotic index in vitro. Moreover, epistatic analyses in vivo showed that dosage perturbations of discrete gene pairings induce microcephaly. Taken together, these studies support a model in which concomitant dosage perturbation of multiple genes within the CNV drive the microcephaly and possibly other neurodevelopmental phenotypes associated with rearrangements in the 17p13.1 SRO. 相似文献
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Specification of the mouse cardiac conduction system in the absence of Endothelin signaling 总被引:1,自引:0,他引:1
Lisa L. Hua Vasanth Vedantham Ralston M. Barnes Jianxin Hu Ashley S. Robinson Michael Bressan Deepak Srivastava Brian L. Black 《Developmental biology》2014
Coordinated contraction of the heart is essential for survival and is regulated by the cardiac conduction system. Contraction of ventricular myocytes is controlled by the terminal part of the conduction system known as the Purkinje fiber network. Lineage analyses in chickens and mice have established that the Purkinje fibers of the peripheral ventricular conduction system arise from working myocytes during cardiac development. It has been proposed, based primarily on gain-of-function studies, that Endothelin signaling is responsible for myocyte-to-Purkinje fiber transdifferentiation during avian heart development. However, the role of Endothelin signaling in mammalian conduction system development is less clear, and the development of the cardiac conduction system in mice lacking Endothelin signaling has not been previously addressed. Here, we assessed the specification of the cardiac conduction system in mouse embryos lacking all Endothelin signaling. We found that mouse embryos that were homozygous null for both ednra and ednrb, the genes encoding the two Endothelin receptors in mice, were born at predicted Mendelian frequency and had normal specification of the cardiac conduction system and apparently normal electrocardiograms with normal QRS intervals. In addition, we found that ednra expression within the heart was restricted to the myocardium while ednrb expression in the heart was restricted to the endocardium and coronary endothelium. By establishing that ednra and ednrb are expressed in distinct compartments within the developing mammalian heart and that Endothelin signaling is dispensable for specification and function of the cardiac conduction system, this work has important implications for our understanding of mammalian cardiac development. 相似文献