High‐Performance and Low‐Temperature Lithium–Sulfur Batteries: Synergism of Thermodynamic and Kinetic Regulation

The intrinsic polysulfides shuttle, resulting from not only concentration‐gradient diffusion but also slow conversion kinetics of polysulfides, bears the primary responsibility for the poor capacity and cycle stability of lithium–sulfur batteries (LSBs). Here, it is first presented that enriched edge sites derived from vertical standing and ultrathin 2D layered metal selenides (2DLMS) can simultaneously achieve the thermodynamic and kinetic regulation for polysulfides diffusion, which is systematically elucidated through theoretical calculation, electrochemical characterization, and spectroscopic/microscopic analysis. When employed to fabricate compact coating layer of separator, an ultrahigh capacity of 1338.7 mA h g^?1 is delivered after 100 cycles at 0.2 C, which is the best among the reports. Over 1000 cycles, the cell still maintains the capacity of 546.8 mA h g^?1 at 0.5 C. Moreover, the cell exhibits outstanding capacities of 1106.2 and 865.7 mA h g^?1 after 100 cycles at stern temperature of 0 and ?25 °C. The superior low‐temperature performance is appealing for extended practical application of LSBs. Especially, in view of the economy, the 2DLMS is recycled as an anode of lithium‐ion and sodium‐ion batteries after finishing the test of LSBs. The low‐cost and scalable 2DLMS with enriched egde sites open a new avenue for the perfect regulation of the sulfur electrode.     

Defense Response to Pathogens Through Epigenetic Regulation in Rice

Epigenetic factors have recently emerged as key regulators of the defense response to pathogens in plants. The epigenetic mechanisms underlying defense regulation have been investigated mostly in Arabidopsis, while our understanding of the epigenetic regulation of defense in rice is limited. In this review, we summarize recent findings surrounding epigenetic mechanisms for defense in rice, primarily focusing on DNA methylation, histone modification, and small RNA regulation. In particular, we focused on RNA-directed DNA methylation (RdDM) and other epigenetic regulatory mechanisms that are involved in disease resistance. Finally, we explored potential epigenetic factors that might regulate the defense response in rice by analyzing available microarray data that can be used to uncover details of epigenetics regulation.     

NOD1 is required for Helicobacter pylori induction of IL‐33 responses in gastric epithelial cells

Helicobacter pylori (H. pylori) causes chronic inflammation which is a key precursor to gastric carcinogenesis. It has been suggested that H. pylori may limit this immunopathology by inducing the production of interleukin 33 (IL‐33) in gastric epithelial cells, thus promoting T helper 2 immune responses. The molecular mechanism underlying IL‐33 production in response to H. pylori infection, however, remains unknown. In this study, we demonstrate that H. pylori activates signalling via the pathogen recognition molecule Nucleotide‐Binding Oligomerisation Domain‐Containing Protein 1 (NOD1) and its adaptor protein receptor‐interacting serine–threonine Kinase 2, to promote production of both full‐length and processed IL‐33 in gastric epithelial cells. Furthermore, IL‐33 responses were dependent on the actions of the H. pylori Type IV secretion system, required for activation of the NOD1 pathway, as well as on the Type IV secretion system effector protein, CagA. Importantly, Nod1^+/+ mice with chronic H. pylori infection exhibited significantly increased gastric IL‐33 and splenic IL‐13 responses, but decreased IFN‐γ responses, when compared with Nod1^?/? animals. Collectively, our data identify NOD1 as an important regulator of mucosal IL‐33 responses in H. pylori infection. We suggest that NOD1 may play a role in protection against excessive inflammation.     

N‐(3‐Oxo‐acyl)‐homoserine lactone induces apoptosis primarily through a mitochondrial pathway in fibroblasts

N‐(3‐Oxododecanoyl)‐l ‐homoserine lactone (C12) is produced by Pseudomonas aeruginosa to function as a quorum‐sensing molecule for bacteria–bacteria communication. C12 is also known to influence many aspects of human host cell physiology, including induction of cell death. However, the signalling pathway(s) leading to C12‐triggered cell death is (are) still not completely known. To clarify cell death signalling induced by C12, we examined mouse embryonic fibroblasts deficient in “initiator” caspases or “effector” caspases. Our data indicate that C12 selectively induces the mitochondria‐dependent intrinsic apoptotic pathway by quickly triggering mitochondrial outer membrane permeabilisation. Importantly, the activities of C12 to permeabilise mitochondria are independent of activation of both “initiator” and “effector” caspases. Furthermore, C12 directly induces mitochondrial outer membrane permeabilisation in vitro. Overall, our study suggests a mitochondrial apoptotic signalling pathway triggered by C12, in which C12 or its metabolite(s) acts on mitochondria to permeabilise mitochondria, leading to activation of apoptosis.     

Lipocalin 2 (Lcn2) interferes with iron uptake by Brucella abortus and dampens immunoregulation during infection of RAW 264.7 macrophages

Lipocalin 2 (Lcn2) is an important innate immunity component against bacterial pathogens. In this study, we report that Lcn2 is induced by Brucella (B.) abortus infection and significantly contributes to the restriction of intracellular survival of Brucella in macrophages. We found that Lcn2 prevented iron uptake by B. abortus through two distinct mechanisms. First, Lcn2 is secreted to capture bacterial siderophore(s) and abrogate iron import by Brucella. Second, Lcn2 decreases the intracellular iron levels during Brucella infection, which probably deprives the invading Brucella of the iron source needed for growth. Suppression of Lcn2 signalling resulted in a marked induction of anti‐inflammatory cytokine, interleukin 10, which was shown to play a major role in Lcn2‐induced antibrucella immunity. Similarly, interleukin 6 was also found to be increased when Lcn2 signalling is abrogated; however, this induction was thought to be an alternative pathway that rescues the cell from infection when the effective Lnc2 pathway is repressed. Furthermore, Lcn2 deficiency also caused a marked decrease in brucellacidal effectors, such as reactive oxygen species and nitric oxide but not the phagolysosome fusion. Taken together, our results indicate that Lcn2 is required for the efficient restriction of intracellular B. abortus growth that is through limiting iron acquisition and shifting cells to pro‐inflammatory brucellacidal activity in murine macrophages.     

Investigation of the diversity of effector genes in the banana pathogen,Fusarium oxysporum f. sp. cubense,reveals evidence of horizontal gene transfer

It is hypothesized that the virulence of phytopathogenic fungi is mediated through the secretion of small effector proteins that interfere with the defence responses of the host plant. In Fusarium oxysporum, one family of effectors, the Secreted In Xylem (SIX) genes, has been identified. We sought to characterize the diversity and evolution of the SIX genes in the banana‐infecting lineages of F. oxysporum f. sp. cubense (Foc). Whole‐genome sequencing data were generated for the 23 genetic lineages of Foc, which were subsequently queried for the 14 known SIX genes (SIX1–SIX14). The sequences of the identified SIX genes were confirmed in a larger collection of Foc isolates. Genealogies were generated for each of the SIX genes identified in Foc to further investigate the evolution of the SIX genes in Foc. Within Foc, variation of the SIX gene profile, including the presence of specific SIX homologues, correlated with the pathogenic race structure of Foc. Furthermore, the topologies of the SIX gene trees were discordant with the topology of an infraspecies phylogeny inferred from EF‐1α/RPB1/RPB2 (translation elongation factor‐1α/RNA polymerase II subunit I/RNA polymerase II subunit II). A series of topological constraint models provided strong evidence for the horizontal transmission of SIX genes in Foc. The horizontal inheritance of pathogenicity genes in Foc counters previous assumptions that convergent evolution has driven the polyphyletic phylogeny of Foc. This work has significant implications for the management of Foc, including the improvement of diagnostics and breeding programmes.     

基于核基因分子多态性的葡萄属物种鉴定

葡萄属(Vitis)植物主要分布于东亚、北美洲以及欧洲至中亚地区。由于葡萄主要采用无性繁殖方式,地区间品种交流较多,同名异物及同物异名现象较为普遍,给葡萄属物种的分类、鉴定造成一定困难。本研究通过序列同源性比对的方法对葡萄属4种植物基因组的保守编码区进行比对,挖掘保守序列93条,经过验证,找到了一条可用于开发多态性分子标记的KOG3174同源序列,并根据该序列设计得到3对引物,可用于4种葡萄的分类、鉴定。