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The configuration optimization design of Low Earth Orbit observation mega constellation in complex space environment is a nonlinear problem that is difficult to solve analytically. In this paper, a constellation design method is proposed, considering satellite imaging width, formation flying of subgroup satellites, and global uniform coverage by payloads. Firstly, a configuration of satellites with the same subsatellite trajectory is proposed, and its orbital analytical expression under J2 perturbation is provided. Then, the relative motion feature points are extracted near the orbit of each satellite, and a group of uniform natural accompanying satellites are set to corresponding points. Afterwards, the orbit parameters of satellite and its companions are set as initial values, and the precise orbits under the High Precision Orbit Propagator model are solved in the neighborhood by using the Nondominated Sort Particle Swarm Optimization algorithm. Finally, the correctness of the configuration design method is verified by numerical simulation.

To determine the critical timing for learning and the associated synaptic plasticity, we analyzed developmental changes in learning together with training-induced plasticity. Rats were subjected to an inhibitory avoidance (IA) task prior to weaning. While IA training did not alter latency at postnatal day (PN) 16, there was a significant increase in latency from PN 17, indicating a critical day for IA learning between PN 16 and 17. One hour after training, acute hippocampal slices were prepared for whole-cell patch clamp analysis following the retrieval test. In the presence of tetrodotoxin (0.5 µM), miniature excitatory postsynaptic currents (mEPSCs) and inhibitory postsynaptic currents (mIPSCs) were sequentially recorded from the same CA1 neuron. Although no changes in the amplitude of mEPSCs or mIPSCs were observed at PN 16 and 21, significant increases in both excitatory and inhibitory currents were observed at PN 23, suggesting a specific critical day for training-induced plasticity between PN 21 and 23. Training also increased the diversity of postsynaptic currents at PN 23 but not at PN 16 and 21, demonstrating a critical day for training-induced increase in the information entropy of CA1 neurons. Finally, we analyzed the plasticity at entorhinal cortex layer III (ECIII)-CA1 or CA3-CA1 synapses for each individual rat. At either ECIII-CA1 or CA3-CA1 synapses, a significant correlation between mean α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid/N-methyl-D-aspartic acid (AMPA/NMDA) ratio and learning outcomes emerged at PN 23 at both synapses, demonstrating a critical timing for the direct link between AMPA receptor-mediated synaptic plasticity and learning efficacy. Here, we identified multiple critical periods with respect to training-induced synaptic plasticity and delineated developmental trajectories of learning mechanisms at hippocampal CA1 synapses.

ABSTRACT Sclerotinia sclerotiorum, a widespread pathogen of dicotyledons, is also a reciprocal endophytic fungus in monocot plants. However, it is unclear how it responds to two distinct plants. Comparative transcriptomic analyses uncovered a network rewiring, with 14.1% up-differentially expressed genes overlapping upon colonizing the endophytic host wheat and a symptomatic host rapeseed. The divergent transcript of genes originating from host-specific induction is central to infection and colonization, including genes related to appressorium, oxalic acid, carbohydrate-active enzymes, and effector-like proteins. We confirmed that appressorium is required for S. sclerotiorum during colonization in symptomatic hosts but not in endophytic wheat via the observation of the infection process of ΔSs-caf1, a compound appressorium formation-defective mutant with hypovirulence to symptomatic hosts. SS1G_10617 and SS1G_13809 are components of the starch degradation pathways. ΔSS1G_10617 displayed lower virulence on symptomatic host plants and abnormal endophytic growth on wheat, and ΔSS1G_13809 only showed an abnormal symbiotic relationship with wheat, implying that starch may be the major carbon source for S. sclerotiorum in the symbiosis with wheat. Our results herein suggest that S. sclerotiorum modulates biphasic colonization via a divergent transcriptional landscape. This study contributes to a better understanding of schizotrophic fungi and provides new clues for cultivating disease-resistant varieties and adjusting reasonable farming strategies. IMPORTANCE The broad host range of fungi with differential fungal responses leads to either a pathogenic or an endophytic lifestyle in various host plants. Yet, the molecular basis of schizotrophic fungal responses to different plant hosts remains unexplored. Here, we observed a general increase in the gene expression of S. sclerotiorum associated with pathogenicity in symptomatic rapeseed, including small protein secretion, appressorial formation, and oxalic acid toxin production. Conversely, in wheat, many carbohydrate metabolism and transport-associated genes were induced, indicating a general increase in processes associated with carbohydrate acquisition. Appressorium is required for S. sclerotiorum during colonization in symptomatic hosts but not in endophytic wheat. These findings provide new clues for understanding schizotrophic fungi, fungal evolution, and the emergence pathways of new plant diseases.

The present study discusses the effects of wheel steered trailer with stability control for multi-articulated vehicles on the lane-keeping performance. For the stability control, the vector follower control is applied to align the direction of the velocity vector at the articulation point with the trailer centerline by steering each trailer wheel. 16 simulations for the tractor and four-trailer combination model, combining with and without a wheel steering of each trailer, are performed. Trailer wheel steering suppresses the direction difference angle at the articulation point and reduces the lateral deviation of the trailer. The forward trailer wheel steering also suppresses the lateral deviation of the unsteered rearward trailer. Based on the relation between the amount of steering input required for stability control and the lateral deviation of each trailer, the lateral deviation is suppressed by steering, however, the steering input required for the stability control is also generated, so the control efficiency depends on the balance between the reduction of the lateral deviation and the required steering input.

Citrus target spot, caused by Pseudofabraea citricarpa, was formerly considered a cold-tolerant fungal disease. However, it has now spread from high-latitude regions to warmer low-latitude regions. Here, we conducted physiological observations on two different strains of the fungus collected from distinct regions, and evaluated their pathogenicity. Interestingly, the CQWZ collected from a low-latitude orchard, exhibited higher temperature tolerance and pathogenicity when compared to the SXCG collected from a high-latitude orchard. To further understand the evolution of temperature tolerance and virulence in these pathogens during the spread process, as well as the mechanisms underlying these differences, we performed genomic comparative analysis. The genome size of CQWZ was determined to be 44,004,669 bp, while the genome size of SXCG was determined to be 45,377,339 bp. Through genomic collinearity analysis, we identified two breakpoints and rearrangements during the evolutionary process of these two strains. Moreover, gene annotation results revealed that the CQWZ possessed 376 annotated genes in the “Xenobiotics biodegradation and metabolism” pathway, which is 79 genes more than the SXCG. The main factor contributing to this difference was the presence of salicylate hydroxylase. We also observed variations in the oxidative stress pathways and core pathogenic genes. The CQWZ exhibited the presence of a heat shock protein (HSP SSB), a catalase (CAT2), and 13 core pathogenic genes, including a LysM effector, in comparison to the SXCG. Furthermore, there were significant disparities in the gene clusters responsible for the production of seven metabolites, such as Fumonisin and Brefeldin. Finally, we identified the regulatory relationship, with the HOG pathway at its core, that potentially contributes to the differences in thermotolerance and virulence. As the global climate continues to warm, crop pathogens are increasingly expanding to new territories. Our findings will enhance understanding of the evolution mechanisms of pathogens under climate change.

Study region: High Mountain Asia (Qinghai-Tibet Plateau and surrounding areas) (HMA) Study focus: Soil dryness and wetness in HMA respond dramatically to global climate change. Monitoring soil moisture can provide a scientific foundation for water security in the plateau, middle, and lower basins. In this study, the applicability of the Temperature Vegetation Dryness Index (TVDI) with three improved protocols was evaluated to rectify the long-standing misuse of the TVDI method for regional drought assessment. New hydrological insights for the regions: The unsuitability of the TVDI in alpine regions was demonstrated by the nonlinear correlation between soil moisture and the TVDI. Among the three improvement schemes, TVDIm (obtained by controlling the temperature variable) best reflected the temporal and spatial distribution of soil moisture in the growing season of HMA, especially for surface soil moisture in the middle- and high-altitude areas. The TVDI, TVDIf (obtained by controlling the wet edge), and TVDI_A (obtained by controlling the partition) are not suitable for drought evaluation in medium- and long-term regions because the correlations between the three indicators and soil moisture are inconsistent in space and time. This study provides a new method to identify whether the TVDI can effectively evaluate regional drought. It also provides a more comprehensive reference for monitoring soil moisture and evaluating dryness in alpine regions using optical remote sensing.

Measurement(s) distributed global population and water withdrawal Technology Type(s) mathematical statistics and analysis

Article highlights A meta-analysis of biochar preparation and application methods for disease severity and plant growth is needed. Soil application of biochar from straw at 350–600 °C and at 3–5% rate was effective in reducing disease severity. Biochar application has better suppression effect on cash crop diseases caused by airborne pathogens. The results of the meta-analysis are particularly useful for maximizing the effect of biochar on plant disease control.

ABSTRACT Glycosylphosphatidylinositol (GPI) anchoring of proteins is a conserved posttranslational modification in eukaryotes. GPI-anchored proteins are widely distributed in fungal plant pathogens, but the specific roles of the GPI-anchored proteins in the pathogenicity of Sclerotinia sclerotiorum, a devastating necrotrophic plant pathogen with a worldwide distribution, remain largely unknown. This research addresses SsGSR1, which encodes an S. sclerotiorum glycine- and serine-rich protein named SsGsr1 with an N-terminal secretory signal and a C-terminal GPI-anchor signal. SsGsr1 is located at the cell wall of hyphae, and deletion of SsGSR1 leads to abnormal cell wall architecture and impaired cell wall integrity of hyphae. The transcription levels of SsGSR1 were maximal in the initial stage of infection, and SsGSR1-deletion strains showed impaired virulence in multiple hosts, indicating that SsGSR1 is critical for the pathogenicity. Interestingly, SsGsr1 targeted the apoplast of host plants to induce cell death that relies on the glycine-rich 11-amino-acid repeats arranged in tandem. The homologs of SsGsr1 in Sclerotinia, Botrytis, and Monilinia species contain fewer repeat units and have lost their cell death activity. Moreover, allelic variants of SsGSR1 exist in field isolates of S. sclerotiorum from rapeseed, and one of the variants lacking one repeat unit results in a protein that exhibits loss of function relative to the cell death-inducing activity and the virulence of S. sclerotiorum. Taken together, our results demonstrate that a variation in tandem repeats provides the functional diversity of GPI-anchored cell wall protein that, in S. sclerotiorum and other necrotrophic pathogens, allows successful colonization of the host plants. IMPORTANCE Sclerotinia sclerotiorum is an economically important necrotrophic plant pathogen and mainly applies cell wall-degrading enzymes and oxalic acid to kill plant cells before colonization. In this research, we characterized a glycosylphosphatidylinositol (GPI)-anchored cell wall protein named SsGsr1, which is critical for the cell wall architecture and the pathogenicity of S. sclerotiorum. Additionally, SsGsr1 induces rapid cell death of host plants that is dependent on glycine-rich tandem repeats. Interestingly, the number of repeat units varies among homologs and alleles of SsGsr1, and such a variation creates alterations in the cell death-inducing activity and the role in pathogenicity. This work advances our understanding of the variation of tandem repeats in accelerating the evolution of a GPI-anchored cell wall protein associated with the pathogenicity of necrotrophic fungal pathogens and prepares the way toward a fuller understanding of the interaction between S. sclerotiorum and host plants.

The strong survival ability of Salmonella in low-moisture foods (LMFs) has been of public concern, and is considered a threat to people’s health. Recently, the development of omics technology has promoted research on the molecular mechanisms of the desiccation stress response of pathogenic bacteria. However, multiple analytical aspects related to their physiological characteristics remain unclear. We explored the physiological metabolism changes of S. enterica Enteritidis exposed to a 24 h-desiccation treatment and a subsequent 3-month desiccation storage in skimmed milk powder (SMP) with an approach of gas chromatography–mass spectrometry (GC–MS) and ultra-performance liquid chromatography-Q Exactive-mass spectrometry (UPLC-QE-MS). A total of 8,292 peaks were extracted, of which 381 were detected by GC–MS and 7,911 peaks were identified by LC–MS/MS, respectively. Through analyses of differentially expressed metabolites (DEMs) and key pathways, a total of 58 DEMs emerged from the 24 h-desiccation treatment, which exhibited the highest relevance for five metabolic pathways, involving glycine, serine, and threonine metabolism, pyrimidine metabolism, purine metabolism, vitamin B6 metabolism, and pentose phosphate pathway. After 3-month SMP storage, 120 DEMs were identified, which were related to several regulatory pathways including arginine and proline metabolism, serine and threonine metabolism, β-alanine metabolism, glycerolipid metabolism, and glycolysis. The analyses of key enzyme activities of XOD, PK, and G6PDH and ATP content provided further evidence that supported the metabolic responses such as nucleic acid degradation, glycolysis, and ATP production played an important role in Salmonella’s adaptation to desiccation stress. This study enables a better understanding of metabolomics-based responses of Salmonella at the initial stage of desiccation stress and the following long-term adaptive stage. Meanwhile, the identified discriminative metabolic pathways may serve as potentially useful targets in developing strategies for the control and prevention of desiccation-adapted Salmonella in LMFs.

Rice false smut caused by Ustilaginoidea virens is one of the most devastating fungal diseases of rice (Oryza sativa) worldwide. Prochloraz and azoxystrobin belong to the groups of demethylation inhibitors and quinone outside inhibitors, respectively, and are commonly used for controlling this disease. In this study, we analyzed the sensitivities of 100 U. virens isolates from Yunnan, Sichuan, Chongqing, and Zhejiang in Southern China to prochloraz and azoxystrobin. The ranges of EC50 for prochloraz and azoxystrobin were 0.004−0.536 and 0.020−0.510 μg/mL, with means and standard errors of 0.062 ± 0.008 and 0.120 ± 0.007 μg/mL, respectively. However, the sensitivity frequency distributions of U. virens to prochloraz and azoxystrobin indicated the emergence of subpopulations with decreased sensitivity. Therefore, the mean EC50 values of 74% and 68% of the isolates at the main peak, 0.031 ± 0.001 and 0.078 ± 0.004 μg/mL, were used as the sensitivity baselines of U. virens to prochloraz and azoxystrobin, respectively. We found significant sensitivity differences to azoxystrobin among different geographical populations and no correlation between the sensitivities of U. virens to prochloraz and azoxystrobin. Among 887 U. virens isolates, the isolate 5-3-1 from Zhejiang showed moderate resistance to prochloraz, with a resistance factor of 22.45, while no nucleotide variation in the 1986-bp upstream or 1827-bp gene regions of CYP51 from 5-3-1 was detected. Overexpression of CYP51 is probably responsible for its resistance to prochloraz. Finally, artificial inoculation showed that 5-3-1 was highly pathogenic to rice, suggesting that the resistance of U. virens to prochloraz must be monitored and managed in Zhejiang.

The compounds involved in the hydroxycinnamic acid amide (HCAA) pathway are an important class of metabolites in plants. Extensive studies have reported that a variety of plant hydroxycinnamamides exhibit pivotal roles in plant–pathogen interactions, such as p-coumaroylagmatine and ferulic acid. The aim of this review is to discuss the emerging findings on the functions of hydroxycinnamic acid amides (HCAAs) accumulation associated with plant defenses against plant pathologies, antimicrobial activity of HCAAs, and the mechanism of HCAAs involved in plant immune responses (such as reactive oxygen species (ROS), cell wall response, plant defense hormones, and stomatal immunity). However, these advances have also revealed the complexity of HCAAs participation in plant defense reactions, and many mysteries remain to be revealed. This review provides an overview of the mechanistic and conceptual insights obtained so far and highlights areas for future exploration of phytochemical defense metabolites.

The Sharply increasing atmospheric nitrogen (N) deposition may substantially impact the N availability and photosynthetic capacity of terrestrial plants. Determining the trade-off relationship between within-leaf N sources and allocation is therefore critical for understanding the photosynthetic response to nitrogen deposition in grassland ecosystems. We conducted field experiments to examine the effects of inorganic nitrogen addition (sole NH4+, sole NO3– and mixed NH4+/NO3–: 50%/50%) on N assimilation and allocation by Leymus chinensis. The leaf N allocated to the photosynthetic apparatus (NPSN) and chlorophyll content per unit area (Chlarea) were significantly positively correlated with the photosynthetic N-use efficiency (PNUE). The sole NO3– treatment significantly increased the plant leaf PNUE and biomass by increasing the photosynthetic N allocation and Chlarea. Under the NO3 treatment, L. chinensis plants devoted more N to their bioenergetics and light-harvesting systems to increase electron transfer. Plants reduced the cell wall N allocation or increased their soluble protein concentrations to balance growth and defense under the NO3 treatment. In the sole NH4+ treatment, however, plants decreased their N allocation to photosynthetic components, but increased their N allocation to the cell wall and elsewhere. Our findings demonstrated that within-leaf N allocation optimization is a key adaptive mechanism by which plants maximize their PNUE and biomass under predicted future global changes.

Study region: The Nagqu River Basin in the central part of the Qinghai–Tibet Plateau, China. Study focus: Groundwater flow systems in permafrost regions are characterized by a unique circulation. Understanding the groundwater circulation mechanism is essential for studying the hydrological effect of permafrost degradation in alpine regions. In this study, potential water sources and origin of solutes in the groundwater of a typical alpine region were studied using hydrochemistry, 18O, 2H and 3H analyses. This research is essential for studying the hydrological effects of permafrost degradation. New hydrological insights for the region: Upon moving from the mountainous region to the plains, the renewal rate decreases from 10.5% to 0.6% and the mean transit time increases from 5–30 to 20–32 years. Groundwater is mainly recharged by ground ice meltwater and infiltration of glacier meltwater, snow meltwater and precipitation in mountainous areas, and by deep groundwater near faults. Discharge to surface water, evaporation, and overflow into springs are the main drainage modes. Water/ice–rock/soil interactions, such as dissolution of aluminosilicate minerals, are the main factors affecting the hydrochemical evolution. This study provides a data-driven approach for understanding groundwater recharge and evolution in similar systems.

Abstract Background Climate change is predicted to lead to changes in the amount and distribution of precipitation during the growing seasonal. This “repackaging” of rainfall could be particularly important for grassland productivity. Here, we designed a two-factor full factorial experiment (three levels of precipitation amount and six levels of dry intervals) to investigate the effect of precipitation patterns on biomass production in Leymus chinensis (Trin.) Tzvel. (a dominant species in the Eastern Eurasian Steppe). Results Our results showed that increased amounts of rainfall with prolonged dry intervals promoted biomass production in L. chinensis by increasing soil moisture, except for the longest dry interval (21 days). However, prolonged dry intervals with increased amount of precipitation per event decreased the available soil nitrogen content, especially the soil NO3 −-N content. For small with more frequent rainfall events pattern, L. chinensis biomass decreased due to smaller plant size (plant height) and fewer ramets. Under large quantities of rain falling during a few events, the reduction in biomass was not only affected by decreasing plant individual size and lower ramet number but also by withering of aboveground parts, which resulted from both lower soil water content and lower NO3 −-N content. Conclusion Our study suggests that prolonged dry intervals between rainfall combined with large precipitation events will dramatically change grassland productivity in the future. For certain combinations of prolonged dry intervals and increased amounts of intervening rainfall, semi-arid grassland productivity may improve. However, this rainfall pattern may accelerate the loss of available soil nitrogen. Under extremely prolonged dry intervals, the periods between precipitation events exceeded the soil moisture recharge interval, the available soil moisture became fully depleted, and plant growth ceased. This implies that changes in the seasonal distribution of rainfall due to climate change could have a major impact on grassland productivity.

In this paper, a novel architecture of area-effective high-radix floating-point divider with low power consumption is proposed. By extending the principle of the standard SRT algorithm, the divider can estimate the partial quotient digits by a simpler circuit and tolerate certain calculation errors in each recurrence cycle. In addition, the accumulation of errors in the recurrence process can be eliminated automatically without additional calculation cycle. The latency and area cost of the divider are linear with the radix number, which solves the problem that the quotient digits selection tables in high-radix divider have high area cost. Base on the proposed architecture a single-precision floating-point divider is implemented, which has an area of 6037.20 $\mu {\mathrm{ m}}^{2}$ in 65nm process. The dynamic power consumption of the divider is only 0.848mW at 250MHz. Compared with other dividers reported in the literature, the area cost can be reduced by about 90% with the same computation precision and performance.

Summary Target spot is a newly emerging citrus disease caused by Pseudofabraea citricarpa. Outbreaks of this disease result in massive economic losses to citrus production. Here, an integrated study involving comparative transcriptomic and secretomic analyses was conducted to determine the critical pathogenicity factors of P. citricarpa involved in the induction of citrus target spot. A total of 701 transcripts and their cognate proteins were quantified and integrated. Among these transcripts and proteins, 99 exhibited the same expression patterns. Our quantitative integrated multi‐omic data highlight several potentially pivotal pathogenicity factors, including 16 unigenes that were annotated as plant cell‐wall‐degrading enzymes, 13 unigenes homologous to virulence factors from various fungi, and one unigene described as a small cysteine‐rich secreted protein, were screened and analysed. The screening of differentially expressed genes that encode secondary metabolism core enzymes implicated terpene metabolism in the pathogenicity of P. citricarpa. Overall, results indicated that plant cell wall degradation, plant–pathogen protein/polyribonucleotide interaction, and terpene biosynthesis have critical roles in the pathogenicity of P. citricarpa. This work demonstrated that integrated omic approaches enable the identification of pathogenicity/virulence factors and provide insights into the mechanisms underlying the pathogenicity of fungi. These insights would aid the development of effective disease management strategies.

Grassland soil organic carbon and nitrogen storage (SOC storage and SNC storage) have been regarded as indicators to evaluate impacts of global climate change on ecosystem functions due to their significant impact on atmospheric carbon (C) concentration. The variations in vegetation and soil properties in diverse vegetation patch types may change soil C and nitrogen (N) sequestration capacity. However, the quantities of SOC and SNC stored and the mechanisms behind the variation in this storage under diverse vegetation patches in grassland ecosystems are still unclear. Here we conducted a field experiment to measure the variations in vegetation composition, soil properties and SOC storage and SNC storage among five common vegetation patch types in the Eastern Eurasian steppe. Then we investigated the link between vegetation variation and the SOC and SNC storage. The results showed that (1) the combined effects of competitive ability and physiological stress drove the unimodal relationship between species diversity and soil pH. (2) Biomass production did not reach its maximum in patch types with the greatest plant diversity due to saline-alkaline stress, but the live vegetation N storage reached its maximum in these highly diverse patches due to complementary resource utilization effects. (3) Although biomass production of patches with the greatest biodiversity did not reach a maximum due to a slight increase in soil pH, the largest SOC and SNC storage values were found in the highly diverse patches. Our study implies that in natural grassland, high levels of species diversity may accelerate the decomposition rate, resulting in more recalcitrant organic C and N are released into the soil. At the same time, our observation that reductions in the area of the originally dominant patch type due to the expansion of other species during grassland degradation suggests that comprehensive measurements of SOC and SNC storage in different vegetation patches should be undertaken for accurate evaluation of the C and N sequestering capacity of grasslands. Our results can also help policy makers determine how to achieve sustainable development of grasslands based on C and N sequestration.

The metro network plays a vital role in the urban transportation system. However, the metro network is easily damaged by humans and natural disturbances. This can cause serious economic damage, such as the suspension of metro station operations and line disruptions. Therefore, we conducted this study in order to minimize the loss caused by the damage to the metro network and improve the performance of the network after recovery. Based on the cascading failures of metro networks, this paper proposes a recovery model for metro networks considering the value of time. Then, considering the time value, a new node importance measure is proposed using the determination of maintenance priorities. The maintenance priorities of nodes with different importance values are investigated to minimize network losses. Lastly, the applicability of the method is verified by a metro network in Zhengzhou city.

Soil rhizosphere microorganisms play crucial roles in promoting plant nutrient absorption and maintaining soil health. However, the effects of different phosphorus (P) managements on soil microbial communities in a slope farming system are poorly understood. Here, rhizosphere microbial communities under two P fertilization levels—conventional (125 kg P2O5 ha–1, P125) and optimal (90 kg P2O5 ha–1, P90)—were compared at four growth stages of maize in a typical sloped farming system. The richness and diversity of rhizosphere bacterial communities showed significant dynamic changes throughout the growth period of maize, while different results were observed in fungal communities. However, both the P fertilization levels and the growth stages influenced the structure and composition of the maize rhizosphere microbiota. Notably, compared to P125, Pseudomonas, Conexibacter, Mycobacterium, Acidothermus, Glomeromycota, and Talaromyces were significantly enriched in the different growth stages of maize under P90, while the relative abundance of Fusarium was significantly decreased during maize harvest. Soil total nitrogen (TN) and pH are the first environmental drivers of change in bacterial and fungal community structures, respectively. The abundance of Gemmatimonadota, Proteobacteria, and Cyanobacteria showed significant correlations with soil TN, while that of Basidiomycota and Mortierellomycota was significantly related to pH. Additionally, P90 strengthened the connection between bacteria, but reduced the links between fungi at the genus level. Our work helps in understanding the role of P fertilization levels in shaping the rhizosphere microbiota and may manipulate beneficial microorganisms for better P use efficiency.

Gummy stem blight (GSB) caused by Didymella bryoniae (D. bryoniae) is a worldwide fungal soil-borne disease that can cause severe yield reduction of watermelon. To shorten the monitoring time of carbendazim-resistant strains of D. bryoniae in the field, in this study, we developed a loop-mediated isothermal amplification (LAMP) assay for rapid detection of carbendazim-resistant strains of D. bryoniae. The β-tubulin gene of carbendazim-resistant strains was selected as the target for primer design. Based on the color change of hydroxy naphthol blue (HNB) and gel electrophoresis, the optimal reaction conditions for LAMP were determined at 65 °C for 50 min. In specificity tests, the LAMP assay was able to distinguish between carbendazim-resistant and sensitive strains of D. bryoniae. Moreover, in sensitivity tests, the detection limit was 1 ng/μL D. bryoniae DNA of the carbendazim-resistant strain. In addition, the LAMP method was successfully applied to detect carbendazim-resistant strains in D. bryoniae-infested samples. Therefore, the developed LAMP assay provides a new method for the rapid detection of carbendazim-resistant strains of D. bryoniae.

Study region: The Nagqu River watershed (NRW) on the Qinghai–Tibet Plateau (QTP). Study focus: Precipitation, snowmelt, streamflow, and groundwater samples were collected in the NRW and used to analyze the contribution of different water sources to streamflow during different freeze–thaw periods. Stable isotopes of hydrogen (D) and oxygen (18O) and water chemistry were analyzed for the period ranging from 2016 to 2019, and tritium (T) and carbon-14 (14C) isotopes were analyzed for 2019. New hydrological insights for the region: Rain and snowmelt were found to reflect the chemical characteristics of precipitation, and the primary ions in both water types were Ca2+ and SO42−. The δD and δ18O isotope values of rain and snowmelt were relatively low during the entire thaw period (from June to October) and relatively high in the entire frozen period (from November to May). The results of the optimum multiparameter and mass balance analyses showed that groundwater and snowmelt accounted for approximately 39.8 % and 32.2 % to the Nagqu River water flow, respectively, whereas precipitation accounted for approximately 28.0 %. The groundwater in clastic rock fissures around the northern Cuona Lake, and permafrost and ground ice in the bedrock layer were identified as older water types with relatively low infiltration rates, and bedrock fissures in the southeastern and southwestern areas contained younger water with better recoverability.

This paper proposes a novel VLSI architecture of GNSS acquisition engine based on short-time correlation combined with an FFT scheme. The architecture supports multi-constellation systems and multi-frequency satellite signals flexibly by the manner of time-division multiplexing. The supported signals include GPS, BDS, GLONASS, GALILEO, QZSS, IRNSS, and SBAS. Compared with other direct acquisition structures, the search efficiency of the acquisition engine is improved by using the IF playback structure. Based on the characteristics of L1C and B1C signal spread spectrum codes, an efficient generation method and the circuit structure of Legendre sequence which is compatible with L1C and B1C spread spectrum codes are proposed. It can effectively reduce the die area of the spread spectrum code generator and the generation time of the L1C/B1C spread spectrum code. Combining with the acquisition scheme adopted in this paper, the structure of the short-time correlators’ array is optimized, and the maximum clock frequency of the acquisition engine is significantly improved. The acquisition engine proposed in this paper is implemented in a 55-nm CMOS technology. The system occupied a silicon area of 2.1 mm2 and consumes only 72.02-mW power while realizing the maximum clock frequency at about 333.33 MHz.

Pathogen infection has greatly reduced crop production. As the symptoms of diseases usually appear when the plants are infected severely, rapid identification approaches are required to monitor plant diseases at early the infection stage and optimize control strategies. Hyperspectral imaging, as a fast and nondestructive sensing technology, has achieved remarkable results in plant disease identification. Various models have been developed for disease identification in different plants such as arable crops, vegetables, fruit trees, etc. In these models, important algorithms, such as the vegetation index and machine learning classification and methods have played significant roles in the detection and early warning of disease. In this paper, the principle of hyperspectral imaging technology and common spectral characteristics of plant disease symptoms are discussed. We reviewed the impact mechanism of pathogen infection on the photo response and spectrum features of the plants, the data processing tools and algorithms of the hyperspectral information of pathogen-infected plants, and the application prospect of hyperspectral imaging technology for the identification of plant diseases.

Study region: The Nagqu River Watershed in the Qinghai–Tibet Plateau. Study focus: A computational unit is the basic spatial unit employed in distributed hydrological models (DHMs), which combines the spatiotemporal distributions of meteorological variables and physical parameters denoted within a region to reveal the characteristics affecting the water cycle of watersheds. However, the current methods developed for spatially divided regions into computational units fail to consider the physical meaning and impact of climate change in montane altitudinal zones (MAZs), which significantly affects alpine watersheds. This study proposes a method for assigning the computational units of alpine DHMs according to one-period MAZ that explicitly account for physical meaning and climate change. New hydrological insights for the region: The benefits of the proposed altitudinal discretization method are verified by applying it to construct a DHM based on the water and energy transfer processes in large river basins (WEP-L) models. The results obtained using the WEP-L, SWAT model and the new regional division method (denoted as the WEP-C model) that applies the proposed altitudinal discretization method are compared. The results demonstrate that the simulation accuracy of the daily and monthly streamflows and daily soil moisture from the alpine watershed is improved by the use of the proposed altitudinal discretization method, which provide guidance for further DHM development and can be applied to other hydrological models.

Region: The Nagqu River Basin in the Qinghai-Tibet Plateau. Focus: Climate change and human activities have altered the type of land use in the Qinghai-Tibet Plateau (QTP), which has affected the variation laws of water resources. We calibrated and verified the Water and Energy Transfer Process for a Large basin model (WEP-L), and calculated the impacts of climate change and human activities on runoff change and separated the impact of land use. New hydrological insights: The Archimedean Copula function was used to diagnose the variance between precipitation and runoff. The contribution of climate change to the runoff in the Dasa and Jiayuqiao subbasin was 81.7% and 71.5%, of which the contribution of land use was 39.3% and 32.6%, respectively. Human activities contributing to the runoff in the Dasa and Jiayuqiao subbasins were 18.3% and 28.5%, of which the contribution of land use is 7.9% and 2.8%, respectively. Climate change has led to the melting of glaciers, permanent permafrost and the shift of the vertical distribution of vegetation, which is the main reason for the runoff variation in the NRB. This research provides a scientific basis for the rational protection and utilization of water resources, as well as soil and water conservation work. Keywords: Precipitation–runoff, Mutation diagnosis, Climate change, Human activities, Land use, Hetao area

Sclerotinia sclerotiorum is a destructive ascomycete plant pathogen with worldwide distribution. Extensive research on different aspects of this pathogen’s capability to cause disease will help to uncover clues about new ways to safely control Sclerotinia diseases. The thioredoxin (Trx) system consists of Trx and thioredoxin reductase (TrxR), which play critical roles in maintenance of cellular redox homeostasis. In this study, we functionally characterized a gene encoding a TrxR (SsTrr1) in S. sclerotiorum. The amino acids of SsTrr1 exhibited high similarity with reported TrxRs in plant pathogens and targeted silencing of SsTrr1 lead to a decrease in TrxR activities of mycelium. SsTrr1 showed high expression levels during hyphae growth, and the levels decreased at the different stages of sclerotial development. SsTrr1 gene-silenced strains produced a smaller number of larger sclerotia on potato dextrose agar medium. The observations were consistent with the inhibitory effects on sclerotial development by the TrxR inhibitor, anrunofin. The expression of SsTrr1 showed a dramatic increase under the oxidative stress and the hyphal growth of gene-silenced strains showed more sensitivity to H2O2. SsTrr1 gene-silenced strains also showed impaired virulence in different hosts. Taken together, our results suggest that SsTrr1 encodes a TrxR that is of great important for oxidative stress tolerance, virulence, and sclerotial development of S. sclerotiorum.

The Ugii Nuur Lake is not only one of the small hydrologically closed lakes located in the Orkhon River Basin in Central Mongolia but also the most vulnerable area for global climate change. Therefore, this study aims to investigate the impacts of recent global climate change on the water surface area. The data we analyzed were various measured hydro-meteorological variables of the lake basin and the lake surface area, which was estimated from Landsat series satellite data from 1986 to 2018. The methods we used were Mann-Kendall (MK), Innovative trend analysis method (ITAM), Sen’s slope estimator test, correlation, and regression analysis. The variation of lake water surface area has a strong positive correlation with the change of the lake water level (r = 0.95). The Mann-Kendall trend analysis has indicated that under a significant decrease in total annual precipitation ( Z = −0.902) and inflow river discharge ( Z = −5.392) and a considerable increase in total annual evaporation ( Z = 4.385) and annual average air temperature ( Z = 4.595), the surface area of the Ugii Nuur Lake has decreased sharply ( Z = −6.021). The total annual evaporation (r = −0.64) and inflow river discharge (r = 0.67) were the essential hydro-meteorological factors affecting the surface area of the Ugii Nuur Lake. The lake surface area decreased by 13.5% in 2018 compared with 1986. In the near future, it is vital to conduct scientific studies considering the volume of lake water, groundwater, and the anthropogenic impact.

Climate change, especially precipitation change, will significantly change soil moisture, which then influences root growth, further affecting yield and grain quality. Previous studies focused on the drought or flood effects on summer maize growth. However, few studied the effects of drought-flood abrupt alternation (DFAA) on the growth of summer maize. We explored the DFAA impacts on the roots, leaf area index (LAI), yield, and grain quality in field. The main results show that DFAA had different impacts on the summer maize growth in the seeding-jointing stage (SJS) and tasseling-grain filling stage (TGS). In general, the DFAA reduced the yield. Roots at the depth of 40 cm had obviously positive impacts on the yield. The DFAA reduced the LAI and promoted the maximum LAI achieving in advance. The grain crude protein augmented under DFAA. The drought had evidently negative impacts on the grain crude fat in the TGS, while it had no obvious influence in the SJS. DFAA had no apparent impact on the grain crude starch. These results could provide some references for the effects and adaptation-strategies study of extreme climate events and their impacts on growth of summer maize.

The freezing−thawing cycle is a basic feature of a frozen soil ecosystem, and it affects the growth of alpine vegetation both directly and indirectly. As the climate changes, the freezing−thawing mode, along with its impact on frozen soil ecosystems, also changes. In this research, the freezing−thawing cycle of the Nagqu River Basin in the Qinghai−Tibet Plateau was studied. Vegetation growth characteristics and microbial abundance were analyzed under different freezing−thawing modes. The direct and indirect effects of the freezing−thawing cycle mode on alpine vegetation in the Nagqu River Basin are presented, and the changing trends and hazards of the freezing−thawing cycle mode due to climate change are discussed. The results highlight two major findings. First, the freezing−thawing cycle in the Nagqu River Basin has a high-frequency mode (HFM) and a low-frequency mode (LFM). With the influence of climate change, the LFM is gradually shifting to the HFM. Second, the alpine vegetation biomass in the HFM is lower than that in the LFM. Frequent freezing−thawing cycles reduce root cell activity and can even lead to root cell death. On the other hand, frequent freezing−thawing cycles increase microbial (Bradyrhizobium, Mesorhizobium, and Pseudomonas) death, weaken symbiotic nitrogen fixation and the disease resistance of vegetation, accelerate soil nutrient loss, reduce the soil water holding capacity and soil moisture, and hinder root growth. This study provides a complete response mechanism of alpine vegetation to the freezing−thawing cycle frequency while providing a theoretical basis for studying the change direction and impact on the frozen soil ecosystem due to climate change.

Rice (Oryza sativa L.) is the only widely cultivated gramineous crops that cannot be infected by rust fungi. To decipher the molecular basis of rice nonhost resistance (NHR) to Puccinia striiformis f. sp. tritici (Pst), the causal agent of wheat stripe rust, proteomic analysis was performed using the two-dimensional electrophoresis (2-DE) technique. The expressed proteins from rice leaves 24 and 48 h post inoculation with Pst and from mock-inoculated leaves were identified. Quantitative analysis revealed a total of 27 differentially expressed proteins in response to Pst inoculation. Most of these proteins fall into the category “response to stimulus” and are involved in basic resistance processes, such as glycerol-3-phosphate and hydrogen peroxide signaling. A homologue of wheat leaf rust resistance protein Lr10 was also identified, implicating multiple layers of plant defense are implicated in rice NHR to Pst. These results demonstrate an intrinsic relationship between host and nonhost resistance. Changes in abundance of these proteins, together with their putative functions reveal a comprehensive profile of rice NHR to Pst and provide new insights into plant immunity.

Sclerotinia sclerotiorum (Lib.) de Bary is a devastating fungal pathogen with worldwide distribution. S. sclerotiorum is a necrotrophic fungus that secretes many cell wall-degrading enzymes (CWDEs) that destroy plant’s cell-wall components. Functional analyses of the genes that encode CWEDs will help explain the mechanisms of growth and pathogenicity of S. sclerotiorum. Here, we isolated and characterized a gene SsXyl1 that encoded an endo-β-1, 4-xylanase in S. sclerotiorum. The SsXyl1 expression showed a slight increase during the development and germination stages of sclerotia and a dramatic increase during infection. The expression of SsXyl1 was induced by xylan. The SsXyl1 deletion strains produce aberrant sclerotia that could not germinate to form apothecia. The SsXyl1 deletion strains also lost virulence to the hosts. This study demonstrates the important roles of endo-β-1, 4-xylanase in the growth and virulence of S. sclerotiorum.

Wheat stripe rust, caused by Puccina striiformis f. sp. tritici (Pst), is one of the most devastating diseases of wheat in China. Rapid change to virulence following release of resistant cultivars necessitates ongoing discovery and exploitation of new resistance resources. Considerable effort has been directed at nonhost resistance (NHR) which is believed to be durable. In the present study we identified rice mutant crr1 (compromised resistance to rust 1) that exhibited compromised NHR to Pst. Compared with wild type rice variety Nipponbare, crr1 mutant displayed a three-fold increase in penetration rates by Pst, and enhanced hyphal growth. The pathogen also developed haustoria in crr1 mesophyll cells, but failed to sporulate. The response to the adapted rice pathogen Magnaporthe oryzae was unchanged in crr1 relative to the wild type. Several defense-related genes involved in the SA- and JA-mediated defense pathways response and in phytoalexin synthesis (such as OsPR1a, OsLOX1, and OsCPS4) were more rapidly and strongly induced in infected crr1 leaves than in the wild type, suggesting that other layers of defense still in effect. Genetic analysis and mapping located the mutant loci at a region between markers ID14 and RM25792, which cover about 290 kb genome sequence on chromosome 10. Further fine mapping and cloning of the locus should provide further insights into NHR to rust fungi in rice, and may reveal new strategies for improving rust resistance in wheat.

Drought-flood abrupt alternation (DFAA) is an extreme hydrological phenomenon caused by meteorological anomalies. To combat the climate change, the watershed integrated management model—Soil and Water Assessment Tool model (SWAT)—was used to simulate DFAA, total nitrogen (TN) and total phosphorus (TP) from 1961 to 2050, based on measured precipitation data in the Hetao area and the downscaled Representative Concentration Pathways (RCPs) climate scenarios. In the future, the increase in temperature and the increase in extreme precipitation will aggravate the pollution of water bodies. Results indicate that the risk of water quality exceeding the standard will increase when DFAA happens, and the risk of water quality exceeding the standard was the greatest in the case of drought-to-flood events. Results also indicate that, against the backdrop of increasing temperature and increasing precipitation in the future, the frequency of long-cycle and short-cycle drought-flood abrupt alternation index (LDFAI, SDFAI) in the Hetao area will continue to decrease, and the number of DFAA situations will decrease. However, the zone of high-frequency DFAA situations will move westward from the eastern Ulansuhai Nur Lake, continuing to pose a risk of water quality deterioration in that region. These results could provide a basis for flood control, drought resistance and pollution control in the Hetao and other areas.

The use of natural antimicrobial compounds in crop production has gained much attention from consumers and the agricultural industry. Consequently, interest in more natural, non-synthetic antimicrobials as potential alternatives to conventional chemical pesticides to combat phytopathogens has heightened. Tea polyphenol (TP), a unique and highly important functional component of tea plants, has been reported to possess antimicrobial properties against a wide spectrum of plant pathogens. The aim of this review is to discuss the emerging findings on the mechanisms of antimicrobial action, and the antimicrobial properties of TP, including their major components, effectiveness, and synergistic effects. More studies, particularly field studies, are still necessary to establish conclusive evidence for the effectiveness of TP against phytopathogens. However, the basic conclusion from existing studies suggests that TP is a potential antimicrobial agent for pesticide reduction in agricultural systems.

The traditional concepts of water resource development and utilization have caused serious hydrological and environmental issues in some regions. In addition, policy issues in China have led to a severe water crisis. The quantitative accounting of water resources is a theoretical approach to solving these problems. In this paper, 13 indicators were selected from four classes, including resources, the environment, society, and efficiency, and a case study of Jinan, Shandong Province, was performed using a set pair analysis model to calculate the water resource assets from 2011–2015. In previous methods of water resource accounting, the water quality was not considered; therefore, the loss coefficient of water resource assets was proposed to improve the reliability of accounting. According to the relationships among the unit price of water, water quantity, and water quality, physical and quantitative accounting methods were used to create water balance sheets from 2011–2015. The calculation results showed that the physical change in water resource assets in Jinan City was −30 million m 3 , and water resource assets initially increased and then decreased. In 2011, 2012, 2013, 2014, and 2015, water resource assets totalled 36.5 million USD, 45.9 million USD, 66.7 million USD, 35.5 million USD, and 37.5 million USD, respectively (at 6.4588, 6.3125, 6.1932, 6.2166, 6.2284 USRMB, respectively). This initial accounting provides quantitative and physical support for the improved management of water resources.

Glycerol-3-phosphate (G3P) is a proposed regulator of plant defense signaling in basal resistance and systemic acquired resistance (SAR). The GLY1-encoded glycerol-3-phosphate dehydrogenase (G3PDH) and GLI1-encoded glycerol kinase (GK) are two key enzymes involved in the G3P biosynthesis in plants. However, their physiological importance in wheat defense against pathogens remains unclear. In this study, quantification analysis revealed that G3P levels were significantly induced in wheat leaves challenged by the avirulent Puccinia striiformis f. sp. tritici (Pst) race CYR23. The transcriptional levels of TaGLY1 and TaGLI1 were likewise significantly induced by avirulent Pst infection. Furthermore, knocking down TaGLY1 and TaGLI1 individually or simultaneously with barley stripe mosaic virus-induced gene silencing (BSMV-VIGS) inhibited G3P accumulation and compromised the resistance in the wheat cultivar Suwon 11, whereas the accumulation of salicylic acid (SA) and the expression of the SA-induced marker gene TaPR1 in plant leaves were altered significantly after gene silencing. These results suggested that G3P contributes to wheat systemic acquired resistance (SAR) against stripe rust, and provided evidence that the G3P function as a signaling molecule is conserved in dicots and monocots. Meanwhile, the simultaneous co-silencing of multiple genes by the VIGS system proved to be a powerful tool for multi-gene functional analysis in plants.

Hydropower, although an attractive renewable energy source, can alter the flux of water, sediments, and biota, producing detrimental impacts in downstream regions. The Mekong River illustrates the impacts of large dams and the limitations of conventional dam regulating strategies. Even under the most optimistic sluicing scenario, sediment load at the Mekong Delta could only recover to 62.3 ± 8.2 million tonnes (1 million tonnes = 109 kilograms), short of the (100 to 160)-million tonne historical level. Furthermore, unless retrofit to reroute sediments, the dams are doomed to continue trapping sediment for at least 170 years and thus starve downstream reaches of sediment, contributing to the impending disappearance of the Mekong Delta. Therefore, we explicitly challenge the widespread use of large dead storages--the portion of the reservoirs that cannot be emptied--in dam designs. Smaller dead storages can ease sediment starvation in downstream regions, thereby buffering against sinking deltas or relative sea level rises. [ABSTRACT FROM AUTHOR]