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1.
Increase of plasma erythroferrone levels during high-altitude exposure: A sub-analysis of the TOP OF HOMe study.
Emrich, IE, Scheuer, A, Wagenpfeil, S, Ganz, T, Heine, GH
American journal of hematology. 2021;(5):E179-E181
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2.
Comparative physiological and root proteome analyses of two sorghum varieties responding to water limitation.
Goche, T, Shargie, NG, Cummins, I, Brown, AP, Chivasa, S, Ngara, R
Scientific reports. 2020;(1):11835
Abstract
When exposed to drought stress many plants reprogram their gene expression to activate adaptive biochemical and physiological responses for survival. However, most of the well-studied adaptive responses are common between drought-sensitive and drought-tolerant species, making it difficult to identify the key mechanisms underpinning successful drought tolerance in crops. We developed a sorghum experimental system that compares between drought-sensitive (ICSB338) and enhanced drought-tolerant (SA1441) varieties. We show that sorghum activates a swift and robust stomatal shutdown to preserve leaf water content when water stress has been sensed. Water uptake is enhanced via increasing root cell water potential through the rapid biosynthesis of predominantly glycine betaine and an increased root-to-shoot ratio to explore more soil volume for water. In addition to stomatal responses, there is a prompt accumulation of proline in leaves and effective protection of chlorophyll during periods of water limitation. Root and stomatal functions rapidly recover from water limitation (within 24 h of re-watering) in the drought-tolerant variety, but recovery is impaired in the drought-sensitive sorghum variety. Analysis of the root proteome revealed complex protein networks that possibly underpin sorghum responses to water limitation. Common and unique protein changes between the two sorghum varieties provide new targets for future use in investigating sorghum drought tolerance.
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3.
Comparative Proteomics and Physiological Analyses Reveal Important Maize Filling-Kernel Drought-Responsive Genes and Metabolic Pathways.
Wang, X, Zenda, T, Liu, S, Liu, G, Jin, H, Dai, L, Dong, A, Yang, Y, Duan, H
International journal of molecular sciences. 2019;(15)
Abstract
Despite recent scientific headway in deciphering maize (Zea mays L.) drought stress responses, the overall picture of key proteins and genes, pathways, and protein-protein interactions regulating maize filling-kernel drought tolerance is still fragmented. Yet, maize filling-kernel drought stress remains devastating and its study is critical for tolerance breeding. Here, through a comprehensive comparative proteomics analysis of filling-kernel proteomes of two contrasting (drought-tolerant YE8112 and drought-sensitive MO17) inbred lines, we report diverse but key molecular actors mediating drought tolerance in maize. Using isobaric tags for relative quantification approach, a total of 5175 differentially abundant proteins (DAPs) were identified from four experimental comparisons. By way of Venn diagram analysis, four critical sets of drought-responsive proteins were mined out and further analyzed by bioinformatics techniques. The YE8112-exclusive DAPs chiefly participated in pathways related to "protein processing in the endoplasmic reticulum" and "tryptophan metabolism", whereas MO17-exclusive DAPs were involved in "starch and sucrose metabolism" and "oxidative phosphorylation" pathways. Most notably, we report that YE8112 kernels were comparatively drought tolerant to MO17 kernels attributable to their redox post translational modifications and epigenetic regulation mechanisms, elevated expression of heat shock proteins, enriched energy metabolism and secondary metabolites biosynthesis, and up-regulated expression of seed storage proteins. Further, comparative physiological analysis and quantitative real time polymerase chain reaction results substantiated the proteomics findings. Our study presents an elaborate understanding of drought-responsive proteins and metabolic pathways mediating maize filling-kernel drought tolerance, and provides important candidate genes for subsequent functional validation.
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4.
Cardiac automaticity: basic concepts and clinical observations.
Vetulli, HM, Elizari, MV, Naccarelli, GV, Gonzalez, MD
Journal of interventional cardiac electrophysiology : an international journal of arrhythmias and pacing. 2018;(3):263-270
Abstract
PURPOSE The purpose of this report was to review the basic mechanisms underlying cardiac automaticity. Second, we describe our clinical observations related to the anatomical and functional characteristics of sinus automaticity. METHODS We first reviewed the main discoveries regarding the mechanisms responsible for cardiac automaticity. We then analyzed our clinical experience regarding the location of sinus automaticity in two unique populations: those with inappropriate sinus tachycardia and those with a dominant pacemaker located outside the crista terminalis region. RESULTS We studied 26 patients with inappropriate sinus tachycardia (age 34 ± 8 years; 21 females). Non-contact endocardial mapping (Ensite 3000, Endocardial Solutions) was performed in 19 patients and high-density contact mapping (Carto-3, Biosense Webster with PentaRay catheter) in 7 patients. The site of earliest atrial activation shifted after each RF application within and outside the crista terminalis region, indicating a wide distribution of atrial pacemaker sites. We also analyzed 11 patients with dominant pacemakers located outside the crista terminalis (age 27 ± 7 years; five females). In all patients, the rhythm was the dominant pacemaker both at rest and during exercise and located in the right atrial appendage in 6 patients, in the left atrial appendage in 4 patients, and in the mitral annulus in 1 patient. Following ablation, earliest atrial activation shifted to the region of the crista terminalis at a slower rate. CONCLUSIONS Membrane and sub-membrane mechanisms interact to generate cardiac automaticity. The present observations in patients with inappropriate sinus tachycardia and dominant pacemakers are consistent with a wide distribution of pacemaker sites within and outside the boundaries of the crista terminalis.
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5.
Middle-aged overweight South Asian men exhibit a different metabolic adaptation to short-term energy restriction compared with Europeans.
Bakker, LE, Guigas, B, van Schinkel, LD, van der Zon, GC, Streefland, TC, van Klinken, JB, Jonker, JT, Lamb, HJ, Smit, JW, Pijl, H, et al
Diabetologia. 2015;(1):165-77
Abstract
AIMS/HYPOTHESIS South Asians have a higher risk of developing type 2 diabetes than Europeans. The underlying cause of this excess risk is still poorly understood but might be related to differences in the regulation of energy/nutrient-sensing pathways in metabolic tissues and subsequent changes in whole-body substrate metabolism. In this study, we investigated the whole-body and skeletal muscle metabolic adaptations to short-term energy restriction in South Asian and European volunteers. METHODS Twenty-four middle-aged overweight South Asian and European men underwent a two-step hyperinsulinaemic-euglycaemic clamp, with skeletal muscle biopsies and indirect calorimetry before and after an 8 day diet very low in energy (very low calorie diet [VLCD]). Abdominal fat distribution and hepatic triacylglycerol content were assessed using MRI and MR spectroscopy. RESULTS South Asian men had higher hepatic triacylglycerol content than European men, and exhibited elevated clamp insulin levels that probably reflect a lower insulin clearance rate. Despite higher insulin levels, endogenous glucose production rate was similar and glucose disposal rate (Rd) and nonoxidative glucose disposal rate (NOGD) were significantly lower in South Asian than European men, indicating impaired whole-body insulin sensitivity. Energy restriction decreased abdominal fat mass and hepatic triacylglycerol content in both groups. However, the shift induced by energy restriction from glucose towards lipid oxidation observed in European men was impaired in South Asian men, indicating whole-body metabolic inflexibility. Remarkably, although energy restriction improved hepatic insulin sensitivity in both groups, Rd improved only in South Asian men owing to higher NOGD. At the molecular level, an increase in insulin-induced activation of the skeletal muscle mTOR pathway was found in South Asian men, showing that skeletal muscle energy/nutrient-sensing pathways were differentially affected by energy restriction. CONCLUSIONS/INTERPRETATION We conclude that South Asian men exhibit a different metabolic adaptation to short-term energy restriction than European men. TRIAL REGISTRATION Dutch trial registry ( www.trialregister.nl ), trial number NTR 2473.
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6.
Water-Based Concurrent Training Improves Peak Oxygen Uptake, Rate of Force Development, Jump Height, and Neuromuscular Economy in Young Women.
Pinto, SS, Alberton, CL, Cadore, EL, Zaffari, P, Baroni, BM, Lanferdini, FJ, Radaelli, R, Pantoja, PD, Peyré-Tartaruga, LA, Wolf Schoenell, MC, et al
Journal of strength and conditioning research. 2015;(7):1846-54
Abstract
The study investigated the effects of different intrasession exercise sequences on the cardiorespiratory and neuromuscular adaptations induced by water-based concurrent training in young subjects. Twenty-six healthy young women (25.1 ± 2.9 years) were placed into 2 water-based concurrent training groups: resistance before (RA, n = 13) or after (AR, n = 13) aerobic training. Subjects trained resistance and aerobic training during 12 weeks, 2 times per week performing both exercise types in the same training session. Peak oxygen uptake (V[Combining Dot Above]O2peak), rate of force development (RFD) obtained during an isometric peak torque knee extension protocol, jump height, and neuromuscular economy (normalized electromyography at 80% of pretraining knee extension isometric peak torque) in young women were determined. After training, there was a significant increase (p < 0.001) in both RA and AR in the V[Combining Dot Above]O2peak, with no differences between groups (7 vs. 5%). The maximal isometric knee extension RFD showed significant increases (p = 0.003) after training (RA: 19 vs. AR: 30%), and both groups presented similar gains. In addition, the countermovement jump height also increased (p = 0.034) after training (RA: 5% vs. AR: 6%), with no difference between groups. After training, there were significant improvements on vastus lateralis (p < 0.001) (RA: -13% vs. AR: -20%) and rectus femoris (p = 0.025) (RA: -17% vs. AR: -7%) neuromuscular economy, with no difference between groups. In conclusion, 12 weeks of water-based concurrent training improved the peak oxygen uptake, RFD, jump height, and neuromuscular economy in young women independent from the intrasession exercise sequence.
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7.
More cells, bigger cells or simply reorganization? Alternative mechanisms leading to changed internode architecture under contrasting stress regimes.
Huber, H, de Brouwer, J, von Wettberg, EJ, During, HJ, Anten, NPR
The New phytologist. 2014;(1):193-204
Abstract
Shading and mechanical stress (MS) modulate plant architecture by inducing different developmental pathways. Shading results in increased stem elongation, often reducing whole-plant mechanical stability, while MS inhibits elongation, with a concomitant increase in stability. Here, we examined how these organ-level responses are related to patterns and processes at the cellular level by exposing Impatiens capensis to shading and MS. Shading led to the production of narrower cells along the vertical axis. By contrast, MS led to the production of fewer, smaller and broader cells. These responses to treatments were largely in line with genetic differences found among plants from open and closed canopy sites. Shading- and MS-induced plastic responses in cellular characteristics were negatively correlated: genotypes that were more responsive to shading were less responsive to MS and vice versa. This negative correlation, however, did not scale to mechanical and architectural traits. Our data show how environmental conditions elicit distinctly different associations between characteristics at the cellular level, plant morphology and biomechanics. The evolution of optimal response to different environmental cues may be limited by negative correlations of stress-induced responses at the cellular level.
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8.
Rapid diversification of five Oryza AA genomes associated with rice adaptation.
Zhang, QJ, Zhu, T, Xia, EH, Shi, C, Liu, YL, Zhang, Y, Liu, Y, Jiang, WK, Zhao, YJ, Mao, SY, et al
Proceedings of the National Academy of Sciences of the United States of America. 2014;(46):E4954-62
Abstract
Comparative genomic analyses among closely related species can greatly enhance our understanding of plant gene and genome evolution. We report de novo-assembled AA-genome sequences for Oryza nivara, Oryza glaberrima, Oryza barthii, Oryza glumaepatula, and Oryza meridionalis. Our analyses reveal massive levels of genomic structural variation, including segmental duplication and rapid gene family turnover, with particularly high instability in defense-related genes. We show, on a genomic scale, how lineage-specific expansion or contraction of gene families has led to their morphological and reproductive diversification, thus enlightening the evolutionary process of speciation and adaptation. Despite strong purifying selective pressures on most Oryza genes, we documented a large number of positively selected genes, especially those genes involved in flower development, reproduction, and resistance-related processes. These diversifying genes are expected to have played key roles in adaptations to their ecological niches in Asia, South America, Africa and Australia. Extensive variation in noncoding RNA gene numbers, function enrichment, and rates of sequence divergence might also help account for the different genetic adaptations of these rice species. Collectively, these resources provide new opportunities for evolutionary genomics, numerous insights into recent speciation, a valuable database of functional variation for crop improvement, and tools for efficient conservation of wild rice germplasm.
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9.
Phenotyping transgenic wheat for drought resistance.
Saint Pierre, C, Crossa, JL, Bonnett, D, Yamaguchi-Shinozaki, K, Reynolds, MP
Journal of experimental botany. 2012;(5):1799-808
Abstract
Realistic experimental protocols to screen for drought adaptation in controlled conditions are crucial if high throughput phenotyping is to be used for the identification of high performance lines, and is especially important in the evaluation of transgenes where stringent biosecurity measures restrict the frequency of open field trials. Transgenic DREB1A-wheat events were selected under greenhouse conditions by evaluating survival and recovery under severe drought (SURV) as well as for water use efficiency (WUE). Greenhouse experiments confirmed the advantages of transgenic events in recovery after severe water stress. Under field conditions, the group of transgenic lines did not generally outperform the controls in terms of grain yield under water deficit. However, the events selected for WUE were identified as lines that combine an acceptable yield-even higher yield (WUE-11) under well irrigated conditions-and stable performance across the different environments generated by the experimental treatments.
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10.
Identification and comparative analysis of microRNAs associated with low-N tolerance in rice genotypes.
Nischal, L, Mohsin, M, Khan, I, Kardam, H, Wadhwa, A, Abrol, YP, Iqbal, M, Ahmad, A
PloS one. 2012;(12):e50261
Abstract
BACKGROUND Nitrogen [N] is a critical limiting nutrient for plants and has to be exogenously supplied to many crops, to achieve high yield with significant economic and environmental costs, specifically for rice. Development of low-input nitrogen sustainable crop is necessary for sustainable agriculture. Identification of regulatory elements associated with low-N tolerance is imperative for formulating innovative approaches for developing low-N tolerant crop plants, using gene manipulation. MicroRNAs (miRNAs) are known to play crucial roles in the modulation of gene expression in plants under various environmental conditions. METHODOLOGY/PRINCIPAL FINDINGS MiRNAs associated with low-N tolerance have not been identified so far. In this study, we investigated microarray-based miRNA expression in low-N tolerant and low-N sensitive rice genotypes under low N condition. Expressions of 32 miRNAs differed significantly in the two genotypes. Of these 32 miRNAs, expressions of nine miRNAs were further validated experimentally in leaves as well as in roots. Of these differentially expressed miRNAs, six miRNAs (miR156, miR164, miR528, miR820, miR821 and miR1318) were reported in leaves and four (miR164, miR167, miR168 and miR528) in roots. Target genes of all the 32 miRNAs were predicted, which encode transcription factors, and proteins associated with metabolic processes or stress responses. Expression levels of some of the corresponding miRNA targets were analysed and found to be significantly higher in low N-tolerant genotype than low-N sensitive genotype. These findings suggested that miRNAs played an important role in low-N tolerance in rice. CONCLUSIONS/SIGNIFICANCE Genome-wide differences in expression of miRNA in low N-tolerant and low N-sensitive rice genotypes were reported. This provides a platform for selection as well as manipulation of genotypes for better N utilization efficiency.