| 1. |
- Liu, Jianguo, et al.
(författare)
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Spillover systems in a telecoupled Anthropocene : typology, methods, and governance for global sustainability
- 2018
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Ingår i: Current Opinion in Environmental Sustainability. - : Elsevier BV. - 1877-3435. ; 33, s. 58-69
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Forskningsöversikt (refereegranskat)abstract
- The world has become increasingly telecoupled through distant flows of information, energy, people, organisms, goods, and matter. Recent advances suggest that telecouplings such as trade and species invasion often generate spillover systems with profound effects. To untangle spillover complexity, we make the first attempt to develop a typology of spillover systems based on six criteria: flows from and to sending and receiving systems, distances from sending and receiving systems, types of spillover effects, sizes of spillover systems, roles of agents in spillover systems, and the origin of spillover systems. Furthermore, we highlight a portfolio of qualitative and quantitative methods for detecting the often-overlooked spillover systems. To effectively govern spillover systems for global sustainability, we propose an overall goal (minimize negative and maximize positive spillover effects) and three general principles (fairness, responsibility, and capability).
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| 2. |
- Liu, Ning-Ning, et al.
(författare)
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Intersection of phosphate transport, oxidative stress and TOR signalling in Candida albicans virulence
- 2018
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Ingår i: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 14:7
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Tidskriftsartikel (refereegranskat)abstract
- Phosphate is an essential macronutrient required for cell growth and division. Pho84 is the major high-affinity cell-surface phosphate importer of Saccharomyces cerevisiae and a crucial element in the phosphate homeostatic system of this model yeast. We found that loss of Candida albicans Pho84 attenuated virulence in Drosophila and murine oropharyngeal and disseminated models of invasive infection, and conferred hypersensitivity to neutrophil killing. Susceptibility of cells lacking Pho84 to neutrophil attack depended on reactive oxygen species (ROS): pho84-/- cells were no more susceptible than wild type C. albicans to neutrophils from a patient with chronic granulomatous disease, or to those whose oxidative burst was pharmacologically inhibited or neutralized. pho84-/- mutants hyperactivated oxidative stress signalling. They accumulated intracellular ROS in the absence of extrinsic oxidative stress, in high as well as low ambient phosphate conditions. ROS accumulation correlated with diminished levels of the unique superoxide dismutase Sod3 in pho84-/- cells, while SOD3 overexpression from a conditional promoter substantially restored these cells' oxidative stress resistance in vitro. Repression of SOD3 expression sharply increased their oxidative stress hypersensitivity. Neither of these oxidative stress management effects of manipulating SOD3 transcription was observed in PHO84 wild type cells. Sod3 levels were not the only factor driving oxidative stress effects on pho84-/- cells, though, because overexpressing SOD3 did not ameliorate these cells' hypersensitivity to neutrophil killing ex vivo, indicating Pho84 has further roles in oxidative stress resistance and virulence. Measurement of cellular metal concentrations demonstrated that diminished Sod3 expression was not due to decreased import of its metal cofactor manganese, as predicted from the function of S. cerevisiae Pho84 as a low-affinity manganese transporter. Instead of a role of Pho84 in metal transport, we found its role in TORC1 activation to impact oxidative stress management: overexpression of the TORC1-activating GTPase Gtr1 relieved the Sod3 deficit and ROS excess in pho84-/- null mutant cells, though it did not suppress their hypersensitivity to neutrophil killing or hyphal growth defect. Pharmacologic inhibition of Pho84 by small molecules including the FDA-approved drug foscarnet also induced ROS accumulation. Inhibiting Pho84 could hence support host defenses by sensitizing C. albicans to oxidative stress.
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| 3. |
- Peng, Yanchun, et al.
(författare)
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Genome-Wide Association Studies of Free Amino Acid Levels by Six Multi-Locus Models in Bread Wheat
- 2018
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Ingår i: Frontiers in Plant Science. - : FRONTIERS MEDIA SA. - 1664-462X. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWAS) have been widely used to dissect the complex biosynthetic processes of plant metabolome. Most studies have used single-locus GWAS approaches, such as mixed linear model (MLM), and little is known about more efficient algorithms to implement multi-locus GWAS. Here, we report a comprehensive GWAS of 20 free amino acid (FAA) levels in kernels of bread wheat (Triticum aestivum L.) based on 14,646 SNPs by six multi-locus models (FASTmrEMMA, FASTmrMLM, ISISEM-BLASSO, mrMLM, pKWmEB, and pLARmEB). Our results showed that 328 significant quantitative trait nucleotides (QTNs) were identified in total (38, 8, 92, 45, 117, and 28, respectively, for the above six models). Among them, 66 were repeatedly detected by more than two models, and 155 QTNs appeared only in one model, indicating the reliability and complementarity of these models. We also found that the number of significant QTNs for different FAAs varied from 8 to 41, which revealed the complexity of the genetic regulation of metabolism, and further demonstrated the necessity of the multi-locus GWAS. Around these significant QTNs, 15 candidate genes were found to be involved in FAA biosynthesis, and one candidate gene (TraesCS1D01G052500, annotated as tryptophan decarboxylase) was functionally identified to influence the content of tryptamine in vitro. Our study demonstrated the power and efficiency of multi-locus GWAS models in crop metabolome research and provided new insights into understanding FAA biosynthesis in wheat.
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