37 research outputs found
Trichostatin A Selectively Suppresses the Cold-Induced Transcription of the ZmDREB1 Gene in Maize
Post-translational modifications of histone proteins play a crucial role in responding to environmental stresses. Histone deacetylases (HDACs) catalyze the removal of an acetyl group from histones and are generally believed to be a transcriptional repressor. In this paper, we report that cold treatment highly induces the up-regulation of HDACs, leading to global deacetylation of histones H3 and H4. Treatment of maize with the HDAC inhibitor trichostatin A (TSA) under cold stress conditions strongly inhibits induction of the maize cold-responsive genes ZmDREB1 and ZmCOR413. However, up-regulation of the ZmICE1 gene in response to cold stress is less affected. The expression of drought and salt induced genes, ZmDBF1 and rab17, is almost unaffected by TSA treatment. Thus, these observations show that HDACs may selectively activate transcription. The time course of TSA effects on the expression of ZmDREB1 and ZmCOR413 genes indicates that HDACs appear to directly activate the ZmDREB1 gene, which in turn modulates ZmCOR413 expression. After cold treatment, histone hyperacetylation and DNA demethylation occurs in the ICE1 binding region, accompanied by an increase in accessibility to micrococcal nuclease (MNase). The two regions adjacent to the ICE1 binding site remain hypoacetylated and methylated. However, during cold acclimation, TSA treatment increases the acetylation status and accessibility of MNase and decreases DNA methylation at these two regions. However, TSA treatment does not affect histone hyperacetylation and DNA methylation levels at the ICE1 binding regions of the ZmDREB1 gene. Altogether, our findings indicate that HDACs positively regulate the expression of the cold-induced ZmDREB1 gene through histone modification and chromatin conformational changes and that this activation is both gene and site selective
Cloning and characterization of miRNAs from maize seedling roots under low phosphorus stress
MicroRNAs (miRNAs) are a class of small, non-coding regulatory RNAs that regulate gene expression by guiding target mRNA cleavage or translational inhibition in plants and animals. In this study, a small RNA library was constructed to identify conserved miRNAs as well as novel miRNAs in maize seedling roots under low level phosphorus stress. Twelve miRNAs were identified by high throughput sequencing of the library and subsequent analysis, two belong to conserved miRNA families (miRNA399b and miRNA156), and the remaining ten are novel and one of latter is conserved in gramineous species. Based on sequence homology, we predicted 125 potential target genes of these miRNAs and then expression patterns of 7 miRNAs were validated by semi-RT-PCR analysis. MiRNA399b, Zma-miR3, and their target genes (Zmpt1 and Zmpt2) were analyzed by real-time PCR. It is shown that both miRNA399b and Zma-miR3 are induced by low phosphorus stress and regulated by their target genes (Zmpt1 and Zmpt2). Moreover, Zma-miR3, regulated by two maize inorganic phosphate transporters as a newly identified miRNAs, would likely be directly involved in phosphate homeostasis, so was miRNA399b in Arabidopsis and rice. These results indicate that both conserved and maize-specific miRNAs play important roles in stress responses and other physiological processes correlated with phosphate starvation, regulated by their target genes. Identification of these differentially expressed miRNAs will facilitate us to uncover the molecular mechanisms underlying the progression of maize seedling roots development under low level phosphorus stress
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Manufacturing and Supply Chain Flexibility: Building an Integrative Conceptual Model Through Systematic Literature Review and Bibliometric Analysis
The purpose of this study is twofold: first, to establish the current themes on the topic of manufacturing and supply chain flexibility (MSCF), assess their level of maturity in relation to each other, identify the emerging ones and reflect on how they can inform each other, and second, to develop a conceptual model of MSCF that links different themes connect and highlight future research opportunities. The study builds on a sample of 222 articles published from 1996 to 2018 in international, peer-reviewed journals. The analysis of the sample involves two complementary approaches: the co-word technique to identify the thematic clusters as well as their relative standing and a critical reflection on the papers to explain the intellectual content of these thematic clusters. The results of the co-word analysis show that MSCF is a dynamic topic with a rich and complex structure that comprises five thematic clusters. The value chain, capability and volatility clusters showed research topics that were taking a central role in the discussion on MSCF but were not mature yet. The SC purchasing practices and SC planning clusters involved work that was more focused and could be considered more mature. These clusters were then integrated in a framework that built on the competence–capability perspective and identified the major structural and infrastructural elements of MSCF as well as its antecedents and consequences. This paper proposes an integrative framework helping managers keep track the various decisions they need to make to increase flexibility from the viewpoint of the entire value chain
Open-Source JTAG Simulator Bundle for Labs
This paper presents a software/hardware bundle for studying, training and research related to IEEE 1149.1 Boundary Scan (BS) standard. The presented package includes a software environment Trainer 1149 that is capable to graphically visualize BS facilities and perform fine-grain simulation of BS test process. Trainer 1149 provides a cozy graphical design and simulation environment of BS-enabled chips and non-BS clusters. It provides the user with a full flexibility in working with any type of BS structures by supporting standard formats such as Boundary Scan Description Language and SVF (for defining test patterns). A special fault simulation mode allows injecting various types of interconnection faults to simulate their impact and inspect them using interactive tools. Trainer 1149 is the main component of a recent goJTAG initiative that aims at bringing JTAG tools closer to the user for both learning and experimental work purposes. The software part is implemented in multi-platform Java environment and distributed as an open-source freeware. Using a convenient low-cost USB-JTAG controller, one can also test real defects in real hardware. Such combination of features is unique for a public domain BS package
Open-Source JTAG Simulator Bundle for Labs
This paper presents a software/hardware bundle for studying, training and research related to IEEE 1149.1 Boundary Scan (BS) standard. The presented package includes a software environment Trainer 1149 that is capable to graphically visualize BS facilities and perform fine-grain simulation of BS test process. Trainer 1149 provides a cozy graphical design and simulation environment of BS-enabled chips and non-BS clusters. It provides the user with a full flexibility in working with any type of BS structures by supporting standard formats such as Boundary Scan Description Language and SVF (for defining test patterns). A special fault simulation mode allows injecting various types of interconnection faults to simulate their impact and inspect them using interactive tools. Trainer 1149 is the main component of a recent goJTAG initiative that aims at bringing JTAG tools closer to the user for both learning and experimental work purposes. The software part is implemented in multi-platform Java environment and distributed as an open-source freeware. Using a convenient low-cost USB-JTAG controller, one can also test real defects in real hardware. Such combination of features is unique for a public domain BS package
Economic analysis of the private law: importance for law-making and law-enforcement in the Russian Federation
В статье представлены результаты исследования, направленного на выявление условий для дальнейшего развития теории экономического анализа частного права в Российской Федерации и ее продвижения в образовательные программы российских вузов. В рамках проведенной работы выполнен методологический анализ частного права, включающий оценку сильных и слабых сторон методологии экономического анализа частного права, возможностей и проблем, связанных с включением метода в образовательные программы вузов.The article is a description of results of research aimed at revealing the conditions of further development of the theory of economic analysis of private law in the Russian Federation and its introduction into the curricula of the Russian higher educational establishments. Methodological analysis of private law is conducted including evaluation of strengths and weaknesses of methodology of private law economic analysis, possibilities and problems resulting from introduction of the method into curricula of higher educational establishments