689 research outputs found

    RNA interference knockdown of BRASSINOSTEROID INSENSITIVE1 in maize reveals novel functions for brassinosteroid signaling in controlling plant architecture

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    Brassinosteroids (BRs) are plant hormones involved in various growth and developmental processes. The BR signaling system is well established in Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa) but poorly understood in maize (Zea mays). BRASSINOSTEROID INSENSITIVE1 (BRI1) is a BR receptor, and database searches and additional genomic sequencing identified five maize homologs including duplicate copies of BRI1 itself. RNA interference (RNAi) using the extracellular coding region of a maize zmbril complementary DNA knocked down the expression of all five homologs. Decreased response to exogenously applied brassinolide and altered BR marker gene expression demonstrate that zmbriI-RNAi transgenic lines have compromised BR signaling. zmbriI-RNAi plants showed dwarf stature due to shortened internodes, with upper internodes most strongly affected. Leaves of zmbriI-RNAi plants are dark green, upright, and twisted, with decreased auricle formation. Kinematic analysis showed that decreased cell division and cell elongation both contributed to the shortened leaves. A BRASSINOSTEROID INSENSITIVE1-ETHYL METHANESULFONATE-SUPPRESSOR1-yellow fluorescent protein (BES1-YFP) transgenic line was developed that showed BR-inducible BES1-YFP accumulation in the nucleus, which was decreased in zmbriI-RNAi. Expression of the BES1-YFP reporter was strong in the auricle region of developing leaves, suggesting that localized BR signaling is involved in promoting auricle development, consistent with the zmbriI-RNAi phenotype. The blade-sheath boundary disruption, shorter ligule, and disrupted auricle morphology of RNAi lines resemble KNOTTED1-LIKE HOMEOBOX (KNOX) mutants, consistent with a mechanistic connection between KNOX genes and BR signaling

    Hiding in plain sight: the globally distributed bacterial candidate phylum PAUC34f

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    © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Chen, M. L., Becraft, E. D., Pachiadaki, M., Brown, J. M., Jarett, J. K., Gasol, J. M., Ravin, N. V., Moser, D. P., Nunoura, T., Herndl, G. J., Woyke, T., & Stepanauskas, R. Hiding in plain sight: the globally distributed bacterial candidate phylum PAUC34f. Frontiers in Microbiology, 11, (2020): 376, doi: 10.3389/fmicb.2020.00376.Bacterial candidate phylum PAUC34f was originally discovered in marine sponges and is widely considered to be composed of sponge symbionts. Here, we report 21 single amplified genomes (SAGs) of PAUC34f from a variety of environments, including the dark ocean, lake sediments, and a terrestrial aquifer. The diverse origins of the SAGs and the results of metagenome fragment recruitment suggest that some PAUC34f lineages represent relatively abundant, free-living cells in environments other than sponge microbiomes, including the deep ocean. Both phylogenetic and biogeographic patterns, as well as genome content analyses suggest that PAUC34f associations with hosts evolved independently multiple times, while free-living lineages of PAUC34f are distinct and relatively abundant in a wide range of environments.This work was funded by the United States National Science Foundation grants 1460861 (REU site at Bigelow Laboratory for Ocean Sciences), 1441717, 1335810, and 1232982 to RS, and the Simons Foundation (Life Sciences Project Award ID 510023) to RS. NR was supported by the Ministry of Science and Higher Education of Russia. GH was supported by the Austrian Science Fund (FWF) project ARTEMIS (P28781-B21) and the European Research Council under the European Community’s Seventh Framework Program (FP7/2007-2013)/ERC (Grant Agreement No. 268595). JG was supported by Spanish project RTI2018-101025-B-I00. TW and JJ were funded by the U.S. Department of Energy, Joint Genome Institute, a DOE Office of Science User Facility supported under Contract No. DE-AC02-05CH11231

    Towards distributed diagnosis of the Tennessee Eastman process benchmark

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    A distributed hybrid strategy is outlined for the isolation of faults and disturbances in the Tennessee Eastman process, which would build on existing structures for distributed control systems, so should be easy to implement, be cheap and be widely applicable. The main emphasis in the paper is on one component of the strategy, a steady-state-based approach. Results obtained by applying this approach are presented and knowledge limitations are discussed. In particular a way in which a knowledge-base might evolve to improve isolation capabilities is suggested and the role of the operator is briefly discussed

    Litter Breakdown And Benthic Invertebrate Detritivores From A Hydrologically Restored Stream

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    The breakdown of coarse forms of detritus into finer forms is an ecosystem function of forested headwater streams. Many factors influence the rate of litter decay, but there is a lack of research on how stream restorations, that aim to restore hydrologic functions, influence litter breakdown. This study compared litter processing rates and macroinvertebrate detritivore assemblages between a hydrologically restored stream (Slabcamp Creek) and an un-restored control stream (White Pine Branch) in the Daniel Boone National Forest in Rowan Co., KY. Red maple (Acer rubrum) leaves were placed in mesh bags and deployed in riffles and pools at the restored and control sites on December 15, 2017. Four litter bags were retrieved from each habitat in streams on five separate occasions. The last set of bags was retrieved on April 7, 2018 after 113 days in the streams. The rate of breakdown from pools of the restored stream was faster (k = 0.0284 d-1) than the rate from the un-restored stream (k = 0.0130 d-1), and analysis indicated a significant difference in rates from pools between streams (p = 0.0021). High variation in restored site physical habitat may have affected litter breakdown. Further, most macroinvertebrate group metrics did not show significant differences between sites in abundance or biomass likely due to large variation from the restored site. However, shredder biomass was greater in restored pools due to a few large Pycnopsyche individuals, and collector-filterers had significantly greater abundance in the restored stream. Findings from this study provide baseline decomposition rates from a hydrologically restored stream and enhance our understanding of ecosystem functions from restored ecosystems

    The Great Basin Experiment Station

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    The Great Basin Experiment Station is unique in its position as a prominent station devoted to the solving of range problems. Because it features an important phase of Forest Service work, it is of interest to foresters generally

    The molecular dimension of microbial species: 1. Ecological distinctions among, and homogeneity within, putative ecotypes of Synechococcus inhabiting the cyanobacterial mat of Mushroom Spring, Yellowstone National Park

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    © 2015 Becraft, Wood, Rusch, Kühl, Jensen, Bryant, Roberts, Cohan and Ward. Based on the Stable Ecotype Model, evolution leads to the divergence of ecologically distinct populations (e.g., with different niches and/or behaviors) of ecologically interchangeable membership. In this study, pyrosequencing was used to provide deep sequence coverage of Synechococcus psaA genes and transcripts over a large number of habitat types in the Mushroom Spring microbial mat. Putative ecological species (putative ecotypes), which were predicted by an evolutionary simulation based on the Stable Ecotype Model (Ecotype Simulation), exhibited distinct distributions relative to temperature-defined positions in the effluent channel and vertical position in the upper 1 mm-thick mat layer. Importantly, in most cases variants predicted to belong to the same putative ecotype formed unique clusters relative to temperature and depth in the mat in canonical correspondence analysis, supporting the hypothesis that while the putative ecotypes are ecologically distinct, the members of each ecotype are ecologically homogeneous. Putative ecotypes responded differently to experimental perturbations of temperature and light, but the genetic variation within each putative ecotype was maintained as the relative abundances of putative ecotypes changed, further indicating that each population responded as a set of ecologically interchangeable individuals. Compared to putative ecotypes that predominate deeper within the mat photic zone, the timing of transcript abundances for selected genes differed for putative ecotypes that predominate in microenvironments closer to upper surface of the mat with spatiotemporal differences in light and O2 concentration. All of these findings are consistent with the hypotheses that Synechococcus species in hot spring mats are sets of ecologically interchangeable individuals that are differently adapted, that these adaptations control their distributions, and that the resulting distributions constrain the activities of the species in space and time

    Quercitron Oak and Its Relation to Soils

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    Quercitron oak (Quercus velutina Lam.) is sparsely distributed in Iowa, being reported by Pammel in only nine counties. The only patch known in Story County is this area some three miles northeast of Ames, which is a narrow strip about three miles long. Here its distribution conforms very definitely with the occurrence of an area of Carrington fine sandy loam, which soil was apparently deposited by glacial streams on common glacial till of boulder clay. The type lacks uniformity in depth, much of it showing less than three feet of sand. Where the sub-soil corresponds, it is light grayish-brown to yellowish sand. The oak has failed to spread to adjacent upland clay loam (Carrington) and terrace silt loam (Wabash), thus showing utter dependence on the fine sandy loam

    CONTRACTS-BROKER\u27S LISTING AGREEMENT-EFFECT OF LEASE OF PROPERTY BY OWNER

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    Plaintiff, a broker, procured from defendant a listing agreement for the sale of defendant\u27s property. Plaintiff produced a purchaser, ready, willing, and able to purchase the property, but defendant refused to convey inasmuch as he had leased the property after giving the listing agreement. The lessee refused to cancel the lease for less than $3,000. Plaintiff brought an action to recover his commission and defendant disclaimed liability as the execution of the lease was known to plaintiff and to the prospective purchaser before the offer to purchase was made. Held, defendant could not alter the plaintiff\u27s rights by placing a lease on the property and the fact that plaintiff knew of the lease before or about the time he produced a purchaser does not affect his right to recover the commission agreed on in the listing agreement. Broomfield v. Abass, (Mich. 1948) 30 N.W. (2d) 874

    An Exploration of the Family\u27s Lived Experience of Autism

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