The root microbiome refers to the community of microbes living in association with a plant's roots, and includes mutualists, pathogens, and commensals. Here we focus on recent advances in the study ...of root commensal community which is the major research object of microbiome‐related researches. With the rapid development of new technologies, plant–commensal interactions can be explored with unprecedented breadth and depth. Both the soil environment and the host plant drive commensal community assembly. The bulk soil is the seed bank of potential commensals, and plants use root exudates and immune responses to build healthy microbial communities from the available microbes. The plant microbiome extends the functional system of plants by participating in a variety of processes, including nutrient absorption, growth promotion, and resistance to biotic and abiotic stresses. Plants and their microbiomes have evolved adaptation strategies over time. However, there is still a huge gap in our understanding of the regulatory mechanisms of plant–commensal interactions. In this review, we summarize recent research on the assembly of root microbial communities and the effects of these communities on plant growth and development, and look at the prospects for promoting sustainable agricultural development through the study of the root microbiome.
Plant roots harbor a taxonomically defined microbial community (root microbiome), the assembly of which is influenced by soil environment and host plant. The root microbiome extends the functional system of plants by participating in a variety of processes, including nutrient absorption, growth promotion, and resistance to biotic and abiotic stresses.
Perovskite X‐ray detectors have been demonstrated to be sensitive to soft X‐rays (<80 keV) for potential medical imaging applications. However, developing X‐ray detectors that are stable and ...sensitive to hard X‐rays (80 to 120 keV) for practical medical imaging is highly desired. Here, a sensitive 2D fluorophenethylammonium lead iodide ((F‐PEA)2PbI4) perovskite single‐crystal hard‐X‐ray detector from low‐cost solution processes is reported. Dipole interaction of organic ions promotes the ordering of benzene rings as well as the supramolecular electrostatic interaction between electron‐deficient F atoms with neighbor benzene rings. Supramolecular interactions serve as a supramolecular anchor to stabilize and tune the electronic properties of single crystals. The 2D (F‐PEA)2PbI4 perovskite single crystal exhibits an intrinsic property with record bulk resistivity of 1.36 × 1012 Ω cm, which brings a low device noise for hard X‐ray detection. Meanwhile, the ion‐migration phenomenon is effectively suppressed, even under the large applied bias of 200 V, by blocking the ion migration paths after anchoring. Consequently, the (F‐PEA)2PbI4 single crystal detector yields a sensitivity of 3402 μC Gy−1air cm−2 to 120 keVp hard X‐rays with lowest detectable X‐ray dose rate of 23 nGyair s−1, outperforming the dominating CsI scintillator of commercial digital radiography systems by acquiring clear X‐ray images under much lower dose rate. In addition, the detector shows high operation stability under extremely high‐flux X‐ray irradiation.
F atoms in an organic spacer of a 2D perovskite enhance the supramolecular electrostatic interactions, serving as supramolecular anchors to stabilize single crystals. The corresponding optoelectronic properties are also improved. A fluorophenethylammonium lead iodide X‐ray detector exhibits stable and sensitive response to 120 keVp X‐rays; clear X‐ray images with detection limit of 23 nGy s−1 are demonstrated.
In Chinese mortuary research, too much reliance on traditional qualitative typological analysis renders quantitative attributes of mortuary practice data ignored. Examining the Taosi cemetery one of ...the famous cemeteries of Neolithic China (2300–1900 BC), this study discusses the advantages and disadvantages of typology and digital methods. Extant qualitative research has classified the Taosi burials into six vertical categories, representing a pyramidal social hierarchy. However, this approach solely relied on the labor expenditure principle, whose outcome was highly subjective and difficult to verify. This study applies a multivariant analysis. Factor analysis is used to investigate the correlations within the mortuary data. The statistical factor scores quantify the differences between the combination of burial objects in different tombs and allow clarification by cluster analysis to investigate their different social meanings. The results reveal two-axial divisions in the Taosi cemetery: vertical stratification based on hierarchy and horizontal differentiation based on social categories/identities. Compared with the simplistic typological description, such a quantitative method reveals the characteristics of each category more clearly, clarifies the classification criteria, and extracts more detailed information about the society and its mortuary practices.
Carbon dots (CDs), comprising crystalline graphitized carbon cores and polymer surface groups, are currently attracting a lot of interest in biological fields owing to their fluorescent properties, ...high photostability, biocompatibility and low toxicity. In addition, the easy preparation and functionalization of CDs stimulate the development of CDs‐based composite materials with specific functions. Presently, the biological applications of CDs are growing at a remarkable speed, justifying the need for up‐to‐date review articles that capture recent progress in this blossoming field. In this review, breakthroughs in the synthesis, modification, optical properties, toxicology and biocatalytic platforms of CDs are described. Further, recent research related to bioimaging, biosensing, drug delivery, antibacterial, anticancer (photothermal therapy, photodynamic therapy and synergistic therapy) and antiviral therapies involving CDs are discussed in detail. Finally, a perspective on the prospects and challenges of CDs in the fields of biomedicine and biotechnology is provided.
The development and application of new functional nanomaterials have always been the focus of various research fields. Among them, carbon dots (CDs) are the newest member of the carbon‐based nanomaterials, which has aroused great interest in bioapplications due to its extraordinary optical and biological properties. Therefore, it is important to make a comprehensive summary of its wide bioapplication values.
Summary
Wheat (Triticum aestivum L.) incurs significant yield losses from powdery mildew, a major fungal disease caused by Blumeria graminis f. sp. tritici (Bgt). enhanced disease resistance1 (EDR1) ...plays a negative role in the defense response against powdery mildew in Arabidopsis thaliana; however, the edr1 mutant does not show constitutively activated defense responses. This makes EDR1 an ideal target for approaches using new genome‐editing tools to improve resistance to powdery mildew. We cloned TaEDR1 from hexaploid wheat and found high similarity among the three homoeologs of EDR1. Knock‐down of TaEDR1 by virus‐induced gene silencing or RNA interference enhanced resistance to powdery mildew, indicating that TaEDR1 negatively regulates powdery mildew resistance in wheat. We used CRISPR/Cas9 technology to generate Taedr1 wheat plants by simultaneous modification of the three homoeologs of wheat EDR1. No off‐target mutations were detected in the Taedr1 mutant plants. The Taedr1 plants were resistant to powdery mildew and did not show mildew‐induced cell death. Our study represents the successful generation of a potentially valuable trait using genome‐editing technology in wheat and provides germplasm for disease resistance breeding.
Significance Statement
In wheat, the conserved mitogen‐activated protein kinase kinase kinase TaEDR1 plays negative roles in resistance to the powdery mildew pathogen. To improve resistance in wheat, we used CRISPR/Cas9 to create plants that carry mutations in the three homoeologs of TaEDR1 in hexaploid bread wheat. The resulting plants show enhanced resistance to powdery mildew, thus providing a potentially valuable tool for broad‐spectrum breeding as well as durable resistance to powdery mildew.
Abstract
Carbon dots (CDs) have received immense attention in the last decade because they are easy-to-prepare, nontoxic, and tailorable carbon-based fluorescent nanomaterials. CDs can be categorized ...into three subgroups based on their morphology and chemical structure: graphene quantum dots (GQDs), carbon quantum dots (CQDs), and carbonized polymer dots (CPDs). The detailed structures of the materials can vary significantly, even within the same category. This property is particularly predominant in chemically synthesized CPDs, as their formation proceeds via the polymerization–carbonization of molecules or polymer precursors. Abundant precursors endow CPDs with versatile structures and properties. A wide variety of carbon nanomaterials can be grouped under the category of CPDs because of their observed diversity. It is important to understand the precursor-dependent structural diversity observed in CPDs. Appropriate nomenclature for all classes and types of CPDs is proposed for the better utilization of these emerging materials.
Conductive hydrogels as flexible electronic devices, not only have unique attractions but also meet the basic need of mechanical flexibility and intelligent sensing. How to endow anisotropy and a ...wide application temperature range for traditional homogeneous conductive hydrogels and flexible sensors is still a challenge. Herein, a directional freezing method is used to prepare anisotropic MXene conductive hydrogels that are inspired by ordered structures of muscles. Due to the anisotropy of MXene conductive hydrogels, the mechanical properties and electrical conductivity are enhanced in specific directions. The hydrogels have a wide temperature resistance range of −36 to 25 °C through solvent substitution. Thus, the muscle‐inspired MXene conductive hydrogels with anisotropy and low‐temperature resistance can be used as wearable flexible sensors. The sensing signals are further displayed on the mobile phone as images through wireless technology, and images will change with the collected signals to achieve motion detection. Multiple flexible sensors are also assembled into a 3D sensor array for detecting the magnitude and spatial distribution of forces or strains. The MXene conductive hydrogels with ordered orientation and anisotropy are promising for flexible sensors, which have broad application prospects in human–machine interface compatibility and medical monitoring.
Inspired by the ordered structure of muscles, MXene conductive hydrogels are anisotropic and can be used as wearable flexible sensors. The conductive hydrogels have the advantages of wide temperature tolerance range, high sensitivity and good stability. The flexible sensors can achieve motion detection through wireless technology and can be assembled into 3D arrays.
Two-dimensional (2D) perovskites have been shown to be more stable than their three-dimensional (3D) counterparts due to the protection of the organic ligands. Herein a method is introduced to form ...2D/3D stacking structures by the reaction of 3D perovskite with n-Butylamine (BA). Different from regular treatment with n-Butylammonium iodide (BAI) where 2D perovskite with various layers form, the reaction of BA with MAPbI3 only produce (BA)2PbI4, which has better protection due to more organic ligands in (BA)2PbI4 than the mixture of 2D perovskites. Compared to BAI treatment, BA treatment results in smoother 2D perovskite layer on 3D perovskites with a better coverage. The photovoltaic devices with 2D/3D stacking structures show much improved stability in comparison to their 3D counterparts when subjected to heat stress tests. Moreover, the conversion of defective surface into 2D layers also induces passivation of the 3D perovskites resulting in an enhanced efficiency.
Self‐assembly of colloidal microspheres or nanospheres is an effective strategy for fabrication of ordered nanostructures. By combination of colloidal self‐assembly with nanofabrication techniques, ...two‐dimensional (2D) colloidal crystals have been employed as masks or templates for evaporation, deposition, etching, and imprinting, etc. These methods are defined as “colloidal lithography”, which is now recognized as a facile, inexpensive, and repeatable nanofabrication technique. This paper presents an overview of 2D colloidal crystals and nanostructure arrays fabricated by colloidal lithography. First, different methods for fabricating self‐assembled 2D colloidal crystals and complex 2D colloidal crystal structures are summarized. After that, according to the nanofabrication strategy employed in colloidal lithography, related works are reviewed as colloidal‐crystal‐assisted evaporation, deposition, etching, imprinting, and dewetting, respectively.
This review article presents an overview of two‐dimensional (2D) colloidal crystals and nanostructure arrays fabricated by colloidal lithography. First, methods for fabricating self‐assembled 2D colloidal crystals and complex 2D colloidal crystal structures are presented. Then, according to the nanofabrication strategy employed in colloidal lithography, related works are reviewed as colloidal‐crystal‐assisted evaporation, deposition, etching, imprinting, and dewetting, respectively.
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