| 1. |
- Chen, Peng, et al.
(författare)
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Relationship between precipitation and Be-10 and impacts on soil dynamics
- 2020
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Ingår i: Catena (Cremlingen. Print). - : Elsevier BV. - 0341-8162 .- 1872-6887. ; 195
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Tidskriftsartikel (refereegranskat)abstract
- Meteoric beryllium-10 (Be-10) is commonly used as a proxy of landscape dynamics (erosion and sedimentation rates) and soil development. Soil represents the first-stage reservoir of meteoric Be-10, and variability in the concentration of the isotope in soils may be affected by soil properties and atmospheric deposition. Although many investigations have targeted this issue, there are still problems in estimating the atmospheric input of the isotope in different soil environments. Here, we used Be-10 data measured in soils distributed across China to explore the potential influence of meteorological and pedological conditions on the isotope concentration and related applications. In addition, to determine the mechanisms controlling Be-10 concentrations in topsoil on a regional scale, the soil samples were sub-divided into 18 different catchments according to fluvial systems. The results indicated that there were significant negative correlations between precipitation and the soil Be-10 concentration in high-precipitation regions (> 1200 mm.y(-1)) and significant positive correlations for soils in low precipitation regions (< 1200 mm.y(-1)). The data also revealed that precipitation is the most important variable controlling the Be-10 concentration in soils of China when compared with the effects of soil properties such as grain size, mineralogy, pH, and cation exchange capacity. Land use and soil erosion may have limited impacts on the distribution of Be-10 in soils.
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| 2. |
- Abbott, Benjamin W., et al.
(författare)
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Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire : an expert assessment
- 2016
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%-85% of permafrost carbon release can still be avoided if human emissions are actively reduced.
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| 3. |
- Chen, Peng, et al.
(författare)
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Transfer RNA modifications and genes for modifying enzymes in Arabidopsis thaliana
- 2010
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Ingår i: BMC Plant Biology. - : BioMed Central. - 1471-2229. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Background: In all domains of life, transfer RNA (tRNA) molecules contain modified nucleosides. Modifications to tRNAs affect their coding capacity and influence codon-anticodon interactions. Nucleoside modification deficiencies have a diverse range of effects, from decreased virulence in bacteria, neural system disease in human, and gene expression and stress response changes in plants. The purpose of this study was to identify genes involved in tRNA modification in the model plant Arabidopsis thaliana, to understand the function of nucleoside modifications in plant growth and development. Results: In this study, we established a method for analyzing modified nucleosides in tRNAs from the model plant species, Arabidopsis thaliana and hybrid aspen (Populus tremula x tremuloides). 21 modified nucleosides in tRNAs were identified in both species. To identify the genes responsible for the plant tRNA modifications, we performed global analysis of the Arabidopsis genome for candidate genes. Based on the conserved domains of homologs in Sacccharomyces cerevisiae and Escherichia coli, more than 90 genes were predicted to encode tRNA modifying enzymes in the Arabidopsis genome. Transcript accumulation patterns for the genes in Arabidopsis and the phylogenetic distribution of the genes among different plant species were investigated. Transcripts for the majority of the Arabidopsis candidate genes were found to be most abundant in rosette leaves and shoot apices. Whereas most of the tRNA modifying gene families identified in the Arabidopsis genome was found to be present in other plant species, there was a big variation in the number of genes present for each family. Through a loss of function mutagenesis study, we identified five tRNA modification genes (AtTRM10, AtTRM11, AtTRM82, AtKTI12 and AtELP1) responsible for four specific modified nucleosides (m1G, m2G, m7G and ncm5U), respectively (two genes: AtKTI12 and AtELP1 identified for ncm5U modification). The AtTRM11 mutant exhibited an early-flowering phenotype, and the AtELP1 mutant had narrow leaves, reduced root growth, an aberrant silique shape and defects in the generation of secondary shoots. Conclusions: Using a reverse genetics approach, we successfully isolated and identified five tRNA modification genes in Arabidopsis thaliana. We conclude that the method established in this study will facilitate the identification of tRNA modification genes in a wide variety of plant species.
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| 4. |
- Ding, Jihua, et al.
(författare)
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GIGANTEA-like genes control seasonal growth cessation in Populus
- 2018
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Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 218:4, s. 1491-1503
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Tidskriftsartikel (refereegranskat)abstract
- Survival of trees growing in temperate zones requires cycling between active growth and dormancy. This involves growth cessation in the autumn triggered by a photoperiod shorter than the critical day length. Variations in GIGANTEA (GI)-like genes have been associated with phenology in a range of different tree species, but characterization of the functions of these genes in the process is still lacking. We describe the identification of the Populus orthologs of GI and their critical role in short-day-induced growth cessation. Using ectopic expression and silencing, gene expression analysis, protein interaction and chromatin immunoprecipitation experiments, we show that PttGIs are likely to act in a complex with PttFKF1s (FLAVIN-BINDING, KELCH REPEAT, F-BOX 1) and PttCDFs (CYCLING DOF FACTOR) to control the expression of PttFT2, the key gene regulating short-day-induced growth cessation in Populus. In contrast to Arabidopsis, in which the GI-CONSTANS (CO)-FLOWERING LOCUS T (FT) regulon is a crucial day-length sensor for flowering time, our study suggests that, in Populus, PttCO-independent regulation of PttFT2 by PttGI is more important in the photoperiodic control of growth cessation and bud set.
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| 5. |
- Sun, Peng, et al.
(författare)
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Scalable three-dimensional Ni 3 P-based composite networks for flexible asymmertric supercapacitors
- 2020
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947. ; 380
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Tidskriftsartikel (refereegranskat)abstract
- Flexible energy storage devices are of great importance in future wearable electronics. To achieve the popularization of these flexible equipments, it is urgent to develop proper productive method for easily scaling up high performance flexible electrode materials. Herein, a three-dimensional nano-network composite material based on Ni3P is designed on flexible carbon felt (CF). The network induced by the introduction of sulfonated polystyrene combines advantages of excellent redox ability of the Ni3P, great conductivity of NiCo alloy and fast electric double layer contribution of carbon. It shows a great energy storage performance and an excellent balance between areal and gravimetric capacitance (1.76 F cm−2 and 1048 F g−1), which are beneficial to the actual application. Besides, this CF@NiCoNiPC can be easily produced in a large-scale due to the simple and low-cost synthetic method. The CF@NiCoNiPC can be further fabricated into an asymmetric supercapacitor (ASC), which demonstrates an excellent capacitance of 516.7 mF cm−2 (170.5 F g−1) and long-term stability of 25,000 charging and discharging cycles (83% retentions). Excitingly, the ASC presents good mechanical performance with 92% capacitance retention after 1000 bending cycles. Three tandem ASCs can easily power a red LED for several minutes when charged for only 20 s even under a bent state, indicating the great potential in future flexible energy storage devices.
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| 6. |
- Wang, Shi Zhi, et al.
(författare)
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Historic dog Furs Unravel the Origin and Artificial Selection of Modern Nordic Lapphund and Elkhound dog Breeds
- 2024
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Ingår i: Molecular biology and evolution. - : Oxford University Press (OUP). - 0737-4038 .- 1537-1719. ; 41:7
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Tidskriftsartikel (refereegranskat)abstract
- The origins and extreme morphological evolution of the modern dog breeds are poorly studied because the founder populations are extinct. Here, we analyse eight 100 to 200 years old dog fur samples obtained from traditional North Swedish clothing, to explore the origin and artificial selection of the modern Nordic Lapphund and Elkhound dog breeds. Population genomic analysis confirmed the Lapphund and Elkhound breeds to originate from the local dog population, and showed a distinct decrease in genetic diversity in agreement with intense breeding. We identified eleven genes under positive selection during the breed development. In particular, the MSRB3 gene, associated with breed-related ear morphology, was selected in all Lapphund and Elkhound breeds, and functional assays showed that a SNP mutation in the 3′UTR region suppresses its expression through miRNA regulation. Our findings demonstrate analysis of near-modern dog artifacts as an effective tool for interpreting the origin and artificial selection of the modern dog breeds.
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