Genome structural variations (SVs) have been associated with key traits in a wide range of agronomically important species; however, SV profiles of peach and their functional impacts remain largely ...unexplored.
Here, we present an integrated map of 202,273 SVs from 336 peach genomes. A substantial number of SVs have been selected during peach domestication and improvement, which together affect 2268 genes. Genome-wide association studies of 26 agronomic traits using these SVs identify a number of candidate causal variants. A 9-bp insertion in Prupe.4G186800, which encodes a NAC transcription factor, is shown to be associated with early fruit maturity, and a 487-bp deletion in the promoter of PpMYB10.1 is associated with flesh color around the stone. In addition, a 1.67 Mb inversion is highly associated with fruit shape, and a gene adjacent to the inversion breakpoint, PpOFP1, regulates flat shape formation.
The integrated peach SV map and the identified candidate genes and variants represent valuable resources for future genomic research and breeding in peach.
Antibiotic resistance is a worldwide public health concern. Conjugative transfer between closely related strains or species of bacteria is an important method for the horizontal transfer of ...multidrug-resistance genes. The extent to which nanomaterials are able to cause an increase in antibiotic resistance by the regulation of the conjugative transfer of antibiotic-resistance genes in bacteria, especially across genera, is still unknown. Here we show that nanomaterials in water can significantly promote the horizontal conjugative transfer of multidrug-resistance genes mediated by the RP4, RK2, and pCF10 plasmids. Nanoalumina can promote the conjugative transfer of the RP4 plasmid from Escherichia coll to Salmonella spp. by up to 200-fold compared with untreated cells. We also explored the mechanisms behind this phenomenon and demonstrate that nanoalumina is able to induce oxidative stress, damage bacterial cell membranes, enhance the expression of mating pair formation genes and DNA transfer and replication genes, and depress the expression of global regulatory genes that regulate the conjugative transfer of RP4. These findings are important in assessing the risk of nanomaterials to the environment, particularly from water and wastewater treatment systems, and in the estimation of the effect of manufacture and use of nanomaterials on the environment.
Iron, cobalt, and nickel chalcogenides are a class of fascinating materials, which have many applications in cutting-edge technologies. Atomic layer deposition (ALD) is a highly useful technique to ...fabricate thin film materials. Over the past few years, ALD of iron, cobalt, and nickel chalcogenides has been developing very rapidly, with many new deposition processes being developed and demonstrated for promising applications. To date, a number of chalcogenides, including FeS x , CoS x , NiS x , Fe x Co1–x S y , FeSe2, CoSe2, and NiSe2, have been successfully synthesized by thermal and/or plasma-assisted ALD, and studies on surface chemistry and film growth mechanisms have also been followed to understand the underlying ALD mechanisms. However, aside from numerous progresses, considerable scientific and technological gaps and challenges are still prominent in this area. In this perspective, we summarize the recent progress in the ALD of iron, cobalt, and nickel chalcogenides, from four aspects of precursors, processes and film properties, surface chemistry and growth mechanisms, and applications, and then present our perspective on the future of this ALD technology.
Abstract
Background
Plant metabolites reshaped by nature and human beings are crucial for both their lives and human health. However, which metabolites respond most strongly to selection pressure at ...different evolutionary stages and what roles they undertake on perennial fruit crops such as peach remain unclear.
Results
Here, we report 18,052 significant locus-trait associations, 12,691 expression-metabolite correlations, and 294,676 expression quantitative trait loci (eQTLs) for peach. Our results indicate that amino acids accumulated in landraces may be involved in the environmental adaptation of peaches by responding to low temperature and drought. Moreover, the contents of flavonoids, the major nutrients in fruits, have kept decreasing accompanied by the reduced bitter flavor during both domestication and improvement stages. However, citric acid, under the selection of breeders’ and consumers’ preference for flavor, shows significantly different levels between eastern and western varieties. This correlates with differences in activity against cancer cells in vitro in fruit from these two regions. Based on the identified key genes regulating flavonoid and acid contents, we propose that more precise and targeted breeding technologies should be designed to improve peach varieties with rich functional contents because of the linkage of genes related to bitterness and acid taste, antioxidant and potential anti-cancer activity that are all located at the top of chromosome 5.
Conclusions
This study provides powerful data for future improvement of peach flavor, nutrition, and resistance in future and expands our understanding of the effects of natural and artificial selection on metabolites.
The metabotropic glutamate receptors (mGlus) are involved in the modulation of synaptic transmission and neuronal excitability in the central nervous system
. These receptors probably exist as both ...homo- and heterodimers that have unique pharmacological and functional properties
. Here we report four cryo-electron microscopy structures of the human mGlu subtypes mGlu2 and mGlu7, including inactive mGlu2 and mGlu7 homodimers; mGlu2 homodimer bound to an agonist and a positive allosteric modulator; and inactive mGlu2-mGlu7 heterodimer. We observed a subtype-dependent dimerization mode for these mGlus, as a unique dimer interface that is mediated by helix IV (and that is important for limiting receptor activity) exists only in the inactive mGlu2 structure. The structures provide molecular details of the inter- and intra-subunit conformational changes that are required for receptor activation, which distinguish class C G-protein-coupled receptors from those in classes A and B. Furthermore, our structure and functional studies of the mGlu2-mGlu7 heterodimer suggest that the mGlu7 subunit has a dominant role in controlling dimeric association and G-protein activation in the heterodimer. These insights into mGlu homo- and heterodimers highlight the complex landscape of mGlu dimerization and activation.
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► One-step solvothermal route to RGO/CdS hybrid materials. ► The hybrid materials exhibit an enhanced photocatalytic degradation activity for MB. ► The optimum loading amount of RGO ...is 5.0wt%. ► The RGO retards the charge recombination of CdS enhancing the degradation efficiency.
Reduced graphene oxide/cadmium sulfide (RGO/CdS) hybrid material was synthesized by a one-step solvothermal method, wherein graphene oxide (GO) was a supporting material on which CdS nanoparticles were distributed homogeneously, and cadmium acetate (Cd(Ac)2·2H2O) was used as the CdS precursor. The supporting material RGO for CdS nanoparticles effectively enhanced their photocatalytic activities for the photodegradation of methylene blue in the aqueous solution. The optimum weight ratio of the GO to CdS in the hybrid material was 5.0%, which exhibited an excellent photodegradation efficiency (94%) and a better removal efficiency of total organic carbon (TOC) (57%), about 2.5 times and 5.1 times higher than that of pure CdS nanoparticles, respectively, under visible light (VL) irradiation. This improved photodegradation efficiency could be attributed to the increased adsorbability for methylene blue molecules, light absorption levels located in visible region, high charge transfer and separation ability, due to the introduction of a two-dimensional RGO network.
•The optimal vaccination strategy for a constrained time-varying SEIR epidemic model is proposed.•The computed vaccination strategy can control the epidemic efficiently.•The comparisons of different ...cases show that omitting the time-varying factors may result in less optimal even unreasonable control strategy.
The optimal control strategy for time-varying epidemic models remains a wide open research area. In this paper, the optimal vaccination strategy for a constrained time-varying SEIR (Susceptible, Exposed, Infected and Recovered) epidemic model is solved under the frame of constrained optimal control problems. Three time-varying factors, i.e., seasonally varying incidence coefficient, monotonic decreasing successfully immune rate and monotonic increasing vaccine yield are considered. Constraints on vaccination rate, susceptible population and vaccine supply at each time instant, which are pure-control constraint, pure-state constraint and mixed state-control constraint, respectively, are all taken into consideration. The characterization for the optimal control is derived with the help of the Pontryagin's maximum principle. And optimal control problems are successfully solved by a symplectic pseudospectral method numerically. Numerical results are consistent with the analytical ones. Finally, comparisons of different cases demonstrate that time-varying factors could alter the optimal vaccination strategy, which implies that omitting the time-varying factors may result in less optimal even unreasonable control strategy.
Chloroplasts in land plants have their own small circular DNA that is presumed to have originated from cyanobacteria-related endosymbionts, and the chloroplast genome is an attractive target to ...improve photosynthetic ability and crop yield. However, to date, most transgenic or genetic engineering technologies for plants are restricted to manipulations of the nuclear genome. In this review, we provide a comprehensive overview of chloroplast genetic engineering and regulation of gene expression from the perspective of history and biology, focusing on current and latest methods. In addition, we suggest techniques that may regulate the chloroplast gene expression at the transcriptional or post-transcriptional level.
This study proposes a multiple-mode collaborative operation strategy for the first time, which integrates compressor inlet air heating mode, gas turbine interstage extraction mode, and back pressure ...heating mode. This operation strategy can improve the peak shaving flexibility of the cogeneration system based on gas turbine combined cycle (GTCC). This article uses Ebsilon software to simulate cogeneration system based on GTCC under different heat and power decoupling technologies and obtain the heat and power operation region. The peak performance of different heat and power decoupling technologies on heating characteristic days are analyzed. Meanwhile, the impact of objective power load changes is studied. The results show that during the whole heating season, compared with the conventional operation mode without heat and power decoupling technology, the multiple-mode collaborative operation strategy, electric boiler (EB) technology, and heat storage tank (HST) technology are adopted, and the renewable energy integration of the cogeneration system based on GTCC are increased by 1.16 × 105 MW, 1.37 × 105 MW and 5.65 × 104 MW, respectively. In addition, When the objective power load is 197.5 MW or 120 MW, taking into account the integration of renewable energy, natural gas consumption, and system benefits, the multiple-mode collaborative operation strategy is the optimal choice.
Chloroplasts cannot develop normally without the coordinated action of various proteins and signaling connections between the nucleus and the chloroplast genome. Many questions regarding these ...processes remain unanswered. Here, we report a novel P-type pentatricopeptide repeat (PPR) factor, named Albino Cotyledon Mutant1 (ACM1), which is encoded by a nuclear gene and involved in chloroplast development. Knock-down of
transgenic plants displayed albino cotyledons but normal true leaves, while knock-out of the
gene in seedlings was lethal. Fluorescent protein analysis showed that ACM1 was specifically localized within chloroplasts. PEP-dependent plastid transcript levels and splicing efficiency of several group II introns were seriously affected in cotyledons in the RNAi line. Furthermore, denaturing gel electrophoresis and Western blot experiments showed that the accumulation of chloroplast ribosomes was probably damaged. Collectively, our results indicate
is indispensable in early chloroplast development in
cotyledons.
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