Abscisic acid (ABA) catabolism is one of the determinants of endogenous ABA levels affecting numerous aspects of plant growth and abiotic-stress responses. The major ABA catabolic pathway is ...triggered by ABA 8'-hydroxylation catalysed by ABA 8'-hydroxylase, the cytochrome P450 CYP707A family. In this study, the full-length cDNAs of AhCYP707A1 and AhCYP707A2 were cloned and characterized from peanut. Expression analyses showed that AhCYP707A1 and AhCYP707A2 were expressed ubiquitously in peanut roots, stems, and leaves with different transcript accumulation levels, including the higher expression of AhCYP707A1 in roots. The expression of AhCYP707A2 was significantly up-regulated by 20% PEG6000 or 250 mmol/L NaCl in peanut roots, stems, and leaves, whereas the up-regulation of AhCYP707A1 transcript level by PEG6000 or NaCl was observed only in roots instead of leaves and stems. Due to the osmotic and ionic stresses of high concentration of NaCl to plants simultaneously, low concentration of LiCl (30 mmol/L, at which concentration osmotic status of cells is not seriously affected, the toxicity of Li+ being higher than that of Na+) was used to examine whether the effect of NaCl might be related to osmotic or ionic stress. The results revealed visually the susceptibility to osmotic stress and the resistance to salt ions in peanut seedlings. The significant up-regulation of AhCYP707A1, AhCYP707A2 and AhNCED1 transcripts and endogenous ABA levels by PEG6000 or NaCl instead of LiCl, showed that the osmotic stress instead of ionic stress affected the expression of those genes and the biosynthesis of ABA in peanut. The functional expression of AhCYP707A1 cDNA in yeast showed that the microsomal fractions prepared from yeast cell expressing recombinant AhCYP707A1 protein exhibited the catalytic activity of ABA 8'-hydroxylase. These results demonstrate that the expressions of AhCYP707A1 and AhCYP707A2 play an important role in ABA catabolism in peanut, particularly in response to osmotic stress.
Direct ink writing technology is capable of using 2D MXene to construct 3D architectures for electrochemical energy storage (EES) devices that are normally difficult to achieve using conventional ...techniques. However, to meet specific rheological requirements for 3D printing, a large amount of MXene is needed in the ink, resulting in a severe self‐restacking structure after drying. Herein, a series of cellulose nanofibers (CNFs) with different morphologies and surface chemistries are applied to enhance the rheology of the MXene‐based inks with exceptional 3D printability. Various 3D architectures with superior shape fidelity and geometric accuracy are successfully printed using the optimized hybrid ink at a low solid content, generating self‐standing, hierarchically porous structures after being freeze‐dried, which improves surface area accessibility, ion transport efficiency, and ultimately, capacitive performance. A solid‐state interdigitated symmetrical supercapacitor is further 3D printed, which delivers an areal capacitance of 2.02 F cm−2 and an energy density of 101 μWh cm−2 at a power density of 0.299 mW cm−2, and maintains a capacitance retention rate of 85% after 5000 cycles. This work demonstrates the integration of 1D CNFs and 2D MXene in 3D printing technology to prepare customized, multiscale, and multidimensional architectures for the next generation of EES devices.
By rationally controlling the dimension and surface chemistry of cellulose nanofibers (CNFs), CNFs are successfully applied as rheology modifiers to formulate viscoelastic, 3D printable MXene‐based ink at a low solid concentration of 8 wt%. The freestanding, hierarchically porous MXene‐based electrode architectures can be achieved by 3D printing and freeze‐drying, which holds great potential in electrochemical energy storage devices.
Summary
Plant microbiomes are essential to host health and productivity but the ecological processes that govern crop microbiome assembly are not fully known.
Here we examined bacterial communities ...across 684 samples from soils (rhizosphere and bulk soil) and multiple compartment niches (rhizoplane, root endosphere, phylloplane, and leaf endosphere) in maize (Zea mays)‐wheat (Triticum aestivum)/barley (Hordeum vulgare) rotation system under different fertilization practices at two contrasting sites.
Our results demonstrate that microbiome assembly along the soil‐plant continuum is shaped predominantly by compartment niche and host species rather than by site or fertilization practice. From soils to epiphytes to endophytes, host selection pressure sequentially increased and bacterial diversity and network complexity consequently reduced, with the strongest host effect in leaf endosphere. Source tracking indicates that crop microbiome is mainly derived from soils and gradually enriched and filtered at different plant compartment niches. Moreover, crop microbiomes were dominated by a few dominant taxa (c. 0.5% of bacterial phylotypes), with bacilli identified as the important biomarker taxa for wheat and barley and Methylobacteriaceae for maize.
Our work provides comprehensive empirical evidence on host selection, potential sources and enrichment processes for crop microbiome assembly, and has important implications for future crop management and manipulation of crop microbiome for sustainable agriculture.
The surge of patients in the pandemic of COVID‐19 caused by the novel coronavirus SARS‐CoV‐2 may overwhelm the medical systems of many countries. Mask‐wearing and handwashing can slow the spread of ...the virus, but currently, masks are in shortage in many countries, and timely handwashing is often impossible. In this study, the efficacy of three types of masks and instant hand wiping was evaluated using the avian influenza virus to mock the coronavirus. Virus quantification was performed using real‐time reverse transcription‐polymerase chain reaction. Previous studies on mask‐wearing were reviewed. The results showed that instant hand wiping using a wet towel soaked in water containing 1.00% soap powder, 0.05% active chlorine, or 0.25% active chlorine from sodium hypochlorite removed 98.36%, 96.62%, and 99.98% of the virus from hands, respectively. N95 masks, medical masks, and homemade masks made of four‐layer kitchen paper and one‐layer cloth could block 99.98%, 97.14%, and 95.15% of the virus in aerosols. Medical mask‐wearing which was supported by many studies was opposed by other studies possibly due to erroneous judgment. With these data, we propose the approach of mask‐wearing plus instant hand hygiene (MIH) to slow the exponential spread of the virus. This MIH approach has been supported by the experiences of seven countries in fighting against COVID‐19. Collectively, a simple approach to slow the exponential spread of SARS‐CoV‐2 was proposed with the support of experiments, literature review, and control experiences.
How do trees support their upright massive bodies? The support comes from the incredibly strong and stiff, and highly crystalline nanoscale fibrils of extended cellulose chains, called cellulose ...nanofibers. Cellulose nanofibers and their crystalline parts—cellulose nanocrystals, collectively nanocelluloses, are therefore the recent hot materials to incorporate in man‐made sustainable, environmentally sound, and mechanically strong materials. Nanocelluloses are generally obtained through a top‐down process, during or after which the original surface chemistry and interface interactions can be dramatically changed. Therefore, surface and interface engineering are extremely important when nanocellulosic materials with a bottom‐up process are fabricated. Herein, the main focus is on promising chemical modification and nonmodification approaches, aiming to prospect this hot topic from novel aspects, including nanocellulose‐, chemistry‐, and process‐oriented surface and interface engineering for advanced nanocellulosic materials. The reinforcement of nanocelluloses in some functional materials, such as structural materials, films, filaments, aerogels, and foams, is discussed, relating to tailored surface and/or interface engineering. Although some of the nanocellulosic products have already reached the industrial arena, it is hoped that more and more nanocellulose‐based products will become available in everyday life in the next few years.
Nanocelluloses, the natural reinforcement for plants, are incredibly strong and stiff, and are therefore under great scrutiny for incorporation in sustainable, ecofriendly, and strong man‐made materials. Nanocelluloses enable dramatic tailoring of surface chemistry, interface interactions, and functionalities via chemical and/or physical surface and interface engineering that permit assembly of diverse nanocellulosic materials. Some of the promising progress in this area is reviewed.
LJF and LF are commonly used in Chinese patent drugs. In the Chinese Pharmacopoeia, LJF and LF once belonged to the same source. However, since 2005, the two species have been listed separately. ...Therefore, they are often misused, and medicinal materials are indiscriminately put in their related prescriptions in China. In this work, firstly, we established a model for discriminating LJF and LF using ATR-FTIR combined with multivariate statistical analysis. The spectra data were further preprocessed and combined with spectral filter transformations and normalization methods. These pretreated data were used to establish pattern recognition models with PLS-DA, RF, and SVM. Results demonstrated that the RF model was the optimal model, and the overall classification accuracy for LJF and LF samples reached 98.86%. Then, the established model was applied in the discrimination of their related prescriptions. Interestingly, the results show good accuracy and applicability. The RF model for discriminating the related prescriptions containing LJF or LF had an accuracy of 100%. Our results suggest that this method is a rapid and effective tool for the successful discrimination of LJF and LF and their related prescriptions.
Summary
Plants harbour highly diverse mycobiomes which sustain essential functions for host health and productivity. However, ecological processes that govern the plant–mycobiome assembly, ...interactions and their impact on ecosystem functions remain poorly known. Here we characterized the ecological role and community assembly of both abundant and rare fungal taxa along the soil–plant continuums (rhizosphere, phyllosphere and endosphere) in the maize–wheat/barley rotation system under different fertilization practices at two contrasting sites. Our results indicate that mycobiome assembly is shaped predominantly by compartment niche and host species rather than by environmental factors. Moreover, crop‐associated fungal communities are dominated by few abundant taxa mainly belonging to Sordariomycetes and Dothideomycetes, while the majority of diversity within mycobiomes are represented by rare taxa. For plant compartments, the abundant sub‐community is mainly determined by stochastic processes. In contrast, the rare sub‐community is more sensitive to host selection and mainly governed by deterministic processes. Furthermore, our results demonstrate that rare taxa play an important role in fungal co‐occurrence network and ecosystem functioning like crop yield and soil enzyme activities. These results significantly advance our understanding of crop mycobiome assembly and highlight the key role of rare taxa in sustaining the stability of crop mycobiomes and ecosystem functions.
Fluoride is considered as one of the most ubiquitous environmental pollutants. Numerous studies have linked reactive oxygen species (ROS)‐dependent oxidative damage with fluoride intoxication, which ...could be prevented by antioxidants. However, the metabolomic changes induced by ROS disruptions in fluoride intoxication are yet unknown. The present study aimed to provide novel mechanistic insights into the fluoride‐induced oxidative damage and to investigate the potential protective effects of ethanolic extract of Prunella vulgaris (natural antioxidant, PV) against fluoride‐induced oxidative damage. The serum biochemical indicators related to fluoride‐induced oxidative damage, such as lipid peroxidation parameter, inflammation and marker enzymes in the liver increased significantly in the fluoride‐treated group, while antioxidant enzymes were decreased. However, PV treatment restored the level of these biochemical indicators, indicating satisfactory antioxidant, anti‐inflammatory, and hepatoprotective potential of PV. The metabolomics analysis in the serum was performed by liquid chromatography–mass spectroscopy, whereas the fluoride treatment caused severe metabolic disorders in rats, which could be improved by PV. The differential metabolites screened by multivariate analysis after fluoride and PV treatment, were organic acids, fatty acids, and lipids. These differential metabolites represented disorders of glyoxylate and dicarboxylate metabolism and the citrate cycle (TCA) according to metabolic pathway analysis in fluoride treatment rats. Interestingly, the result of metabolic pathway analysis of post‐treatment with PV was consistent with that of fluoride treatment, indicating that the energy metabolism plays a major role in the progress of fluoride‐induced oxidative damage, as well as the therapeutic effect of PV. These findings provided a theoretical basis for understanding the mechanism underlying metabolic disorders of fluoride toxicity and the effect of PV.
Summary
Viruses can affect microbial dynamics, metabolism and biogeochemical cycles in aquatic ecosystems. However, viral diversity and functions in agricultural soils are poorly known, especially in ...the rhizosphere. We used virome analysis of eight rhizosphere and bulk soils to study viral diversity and potential biogeochemical impacts in an agro‐ecosystem. The order Caudovirales was the predominant viral type in agricultural soils, with Siphoviridae being the most abundant family. Phylogenetic analysis of the terminase large subunit of Caudovirales identified high viral diversity and three novel groups. Viral community composition differed significantly between bulk and rhizosphere soils. Soil pH was the main environmental driver of the viral community structure. Remarkably, abundant auxiliary carbohydrate‐active enzyme (CAZyme) genes were detected in viromes, including glycoside hydrolases, carbohydrate esterases and carbohydrate‐binding modules. These results demonstrate that virus‐encoded putative auxiliary metabolic genes or metabolic genes that may change bacterial metabolism and indirectly contribute to biogeochemical cycling, especially carbon cycling, in agricultural soil.
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