37 research outputs found

    Loss of Arabidopsis matrix metalloproteinase-5 affects root development and root bacterial communities during drought stress

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    Matrix metalloproteinases (MMPs) are zinc-dependent endo-peptidases that in mammals are known to be involved in remodeling the extracellular matrix (ECM) in developmental and pathological processes. In this study, we report At5-MMP of Arabidopsis thaliana to be important for root development and root bacterial communities. At5-MMP is mainly localized in the root vasculature and lateral root, an At5-MMP T-DNA insertion mutant (mmp5 KO) showed reduced root growth and a lower number of root apexes, causing reduced water uptake from the soil. Subsequently, mmp5 KO is sensitive to drought stress. Inhibited auxin transport was accompanied with resistance to indole-3-acetic acid (IAA), 2, 4-dichlorophenoxyacetic acid (2, 4-D), and 1-naphthaleneacetic acid (NAA). The content of endogenous abscisic acid (ABA) was lower in roots of mmp5 KO than in wild type. Genes responsive to ABA as well as genes encoding enzymes of the proline biosynthesis were expressed to a lower extent in mmp5 KO than in wild type. Moreover, drought stress modulated root-associated bacterial communities of mmp5 KO: the number of Actinobacteria increased. Therefore, At5-MMP modulates auxin/ABA signaling rendering the plant sensitive to drought stress and recruiting differential root bacterial communities

    PENGARUH KUALITAS DAN FITUR TERHADAP MANFAAT DAN KEPUASAN PENGGUNA E-COMMERCE

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    Penelitian ini ingin mengetahui apakah kualitas dan fitur yang mempengaruhi manfaat dan kepuasan pengguna e-commerce. Penelitian ini dilakukan di Universitas Katolik Soegijapranata Semarang dan dilaksanakan pada tahun 2015. Metode yang digunakan dalam penelitian ini menggunakan pendekatan kuantitatif yaitu melalui survey lapangan dengan analisis statistik. Responden dalam penelitian ini adalah mahasiswa Fakultas Ekonomi dan Bisnis yang sudah maupun sedang mengambil mata kuliah SIM serta memiliki pengalaman berkunjung ke situs e-commerce. Kemudian data diolah menggunakan SmartPLS . Hasil penelitian ini menyimpulkan bahwa faktor yang mempengaruhi kepuasan para konsumenadalah fitur dan manfaat (usefulness), sedangkan yang mempengaruhi manfaat yang dirasakan oleh responden adalah kualitas sistem. Akan tetapi, kualitas informasi dan pelayanan dirasakan tidak mempengaruhi kepuasan dan manfaat yang dirasakan

    PEMBUDAYAAN PERMENDIKBUD NOMOR 82 TAHUN 2015 TENTANG PENCEGAHAN DAN PENANGGULANGAN TINDAK KEKERASAN DI LINGKUNGAN SATUAN PENDIDIKAN DI SMP PL DOMENICO SAVIO SEMARANG

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    Kekerasan di sekolah atau yang lebih dikenal dengan istilah perundungan/bullying sampai saat masih sering terjadi dan semakin memprihatinkan. Oleh karena itu, pemerintah pada tanggal 31 Desember 2015 akhirnya menerbitkan Peraturan Menteri Pendidikan dan Budaya (Permendikbud) Nomor 82 Tahun 2015 tentang Pencegahan dan Penanggulangan Tindak Kekerasan di Lingkungan Satuan Pendidikan untuk mendorong sekolah dan pemerintah daerah agar melakukan upaya pencegahan dan penanggulangan terhadap tindak kekerasan di sekolah. Penelitian ini bertujuan untuk mengetahui pembudayaan hukum Permendikbud Nomor 82 Tahun 2015 tentang Pencegahan dan Penanggulangan Tindak Kekerasan Di Lingkungan Satuan Pendidikan Di SMP PL Domenico Savio Semarang melalui tanggapan, pendapat komunitas sekolah (kepala sekolah, guru dan peserta didik), serta sarana dan prasarana yang disediakan dalam rangka menanggapi Permendikbud tersebut. Penelitian ini dilakukan dengan menggunakan metode pendekatan kualitatif dengan analisis yang bersifat deskriptif. Objek penelitian yaitu, segala informasi yang berhubungan dengan pembudayaan Permendikbud Nomor 82 Tahun 2015 tentang Pencegahan dan Penanggulangan Tindak Kekerasan di Lingkungan Satuan Pendidikan di SMP PL Domenico Savio Semarang. Hasil penelitian menunjukkan bahwa, pembudayaan Permendikbud tersebut bersifat partisipan. Hal ini nampak dari tanggapan, sarana dan prasarana yang telah disediakan oleh respo

    The rice XA21 ectodomain fused to the Arabidopsis EFR cytoplasmic domain confers resistance to Xanthomonas oryzae pv. oryzae

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    Rice (Oryza sativa) plants expressing the XA21 cell-surface receptor kinase are resistant to Xanthomonas oryzae pv. oryzae (Xoo) infection. We previously demonstrated that expressing a chimeric protein containing the ELONGATION FACTOR Tu RECEPTOR (EFR) ectodomain and the XA21 endodomain (EFR: XA21) in rice does not confer robust resistance to Xoo. To test if the XA21 ectodomain is required for Xoo resistance, we produced transgenic rice lines expressing a chimeric protein consisting of the XA21 ectodomain and EFR endodomain (XA21:EFR) and inoculated these lines with Xoo. We also tested if the XA21:EFR rice plants respond to a synthetic sulfated 21 amino acid derivative (RaxX21-sY) of the activator of XA21-mediated immunity, RaxX. We found that five independently transformed XA21:EFR rice lines displayed resistance to Xoo as measured by lesion length analysis, and showed that five lines share characteristic markers of the XA21 defense response (generation of reactive oxygen species and defense response gene expression) after treatment with RaxX21-sY. Our results indicate that expression of the XA21:EFR chimeric receptor in rice confers resistance to Xoo. These results suggest that the endodomain of the EFR and XA21 immune receptors are interchangeable and the XA21 ectodomain is the key determinant conferring robust resistance to Xoo.This project was funded through NIH grant GM59962 and the NSF PGRP grant IOS1237975. Benjamin Schwessinger was supported by a Human Frontiers Science Program long-term postdoctoral fellowship (LT000674/2012) and a Discovery Early Career Research Award (DE150101897)

    Four tyrosine residues of the rice immune receptor XA21 are not required for interaction with the co-receptor OsSERK2 or resistance to Xanthomonas oryzae pv. oryzae

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    Tyrosine phosphorylation has emerged as an important regulator of plasma membrane-localized immune receptors activity. Here, we investigate the role of tyrosine phosphorylation in the regulation of rice XANTHOMONAS RESISTANCE 21 (XA21)-mediated immunity. We demonstrate that the juxtamembrane and kinase domain of Escherichia coli–expressed XA21 (XA21JK) autophosphorylates on tyrosine residues. Directed mutagenesis of four out of the nine tyrosine residues in XA21JK reduced autophosphorylation. These sites include Tyr698 in the juxtamembrane domain, and Tyr786, Tyr907, and Tyr909 in the kinase domain. Rice plants expressing XA21-GFP fusion proteins or proteins with these tyrosine residues individually mutated to phenylalanine (XA21YF-GFP), which prevents phosphorylation at these sites, maintain resistance to Xanthomonas oryzae pv. oryzae. In contrast, plants expressing phosphomimetic XA21 variants with tyrosine mutated to aspartate (XA21YD-GFP) were susceptible. In vitro purified XA21JKY698F, XA21JKY907F, and XA21JKY909F variants are catalytically active, whereas activity was not detected in XA21JKY768F and the four XA21JKYD variants. We previously demonstrated that interaction of XA21 with the co-receptor OsSERK2 is critical for biological function. Four of the XA21JKYF variants maintain interaction with OsSERK2 as well as the XA21 binding (XB) proteins XB3 and XB15 in yeast, suggesting that these four tyrosine residues are not required for their interaction. Taken together, these results suggest that XA21 is capable of tyrosine autophosphorylation, but the identified tyrosine residues are not required for activation of XA21-mediated immunity or interaction with predicted XA21 signaling proteins

    Genome-resolved metagenomics reveals role of iron metabolism in drought-induced rhizosphere microbiome dynamics

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    Recent studies have demonstrated that drought leads to dramatic, highly conserved shifts in the root microbiome. At present, the molecular mechanisms underlying these responses remain largely uncharacterized. Here we employ genome-resolved metagenomics and comparative genomics to demonstrate that carbohydrate and secondary metabolite transport functionalities are overrepresented within drought-enriched taxa. These data also reveal that bacterial iron transport and metabolism functionality is highly correlated with drought enrichment. Using time-series root RNA-Seq data, we demonstrate that iron homeostasis within the root is impacted by drought stress, and that loss of a plant phytosiderophore iron transporter impacts microbial community composition, leading to significant increases in the drought-enriched lineage, Actinobacteria. Finally, we show that exogenous application of iron disrupts the drought-induced enrichment of Actinobacteria, as well as their improvement in host phenotype during drought stress. Collectively, our findings implicate iron metabolism in the root microbiome’s response to drought and may inform efforts to improve plant drought tolerance to increase food security

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
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