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Potential spatiotemporal distribution changes and conservation recommendations of two connected endangered tree peony species (Paeonia decomposita & P. rotundiloba)
No full textGenus Paeonia L. has important economic values in ornamental, medicine and food. China is one of the distri-bution centers of Paeonia and the origin to all wild species of section Moutan. Nowadays, most tree peonies species are in danger of extinction, but their geographical distribution is still unclear, hindering further resource protection. In this work, based on comprehensive environmental data and long-term presence records, the maximum entropy (MaxEnt) model was used to predict the past, current and future potential distribution of two Chinese endemic and endangered species, Paeonia decomposita and Paeonia rotundiloba. The results showed that the two species were narrowly distributed in Western Sichuan (Aba and Ganzi), China, with the temperature seasonality and UV-B seasonality being the most important environmental variables to determine the habitat suitability of the both tree peonies. In addition, growing degree days and precipitation seasonality also had an important impact on P. decomposita and P. rotundiloba, respectively. The reconstitution for the past distribution showed that they were mainly distributed in the south foot of Hengduan Mountains in the last interglacial (LIG) period. The reconstitution for historical suitable distribution indicated that the two tree peonies would migrated along Hengduan Mountains and Yarlung Zangbo River into the southeast of Qinghai Tibet Plateau, northeast from the current distribution. The areas of current potential distribution of the two tree peonies, which were partially crossed, were 14050 km2 and 45299 km2 respectively. Under different future climate scenarios, the potential distribution of the two peonies continued to expand and migrated to high-altitude areas in the north if the greenhouse gas concentration will continue to increase. This study will not only provide theoretical guidance for the conservation of P. decomposita and P. rotundiloba, but also help to understand the evolution and migration process of section Moutan
Shrub encroachment drives different responses of soil respiration to increased precipitation and N enrichment
No full textIn the context of global change, changes in precipitation patterns and increases in atmospheric nitrogen (N) deposition have important impacts on grassland ecosystem processes and functions, such as soil respiration. However, most studies on the effects of increased precipitation and N enrichment on soil respiration have focused on pure grassland vegetation types (such as typical steppe), but less on grassland at different stages of shrub encroachment. Here, we examined the effects of increased precipitation and N enrichment on soil respiration and its components (heterotrophic and autotrophic respiration) in different stages of shrub-encroached steppe (i.e., no shrub invasion, light, moderate and severe encroachment) based on water and N addition experiments. Our results showed that increased precipitation greatly promoted soil respiration in typical steppe, lightly and moderately shrub-encroached steppe, but had no significant effects in severely encroached steppe; particularly, soil respiration in a wet year (2021) was significantly higher than that in a dry year (2020). However, N addition had no significant effect on soil respiration across the four stages of shrub encroachment, mainly due to the severe soil water limitation. In general, shrub encroachment significantly reduced soil respiration in Inner Mongolia steppe, mainly by increasing soil temperature, but decreasing soil moisture, microbial biomass and root biomass. We found that the driving factors of soil respiration varied with the development of shrub encroachment, especially the biological factors gradually shifted from aboveground plant community to underground microbial community. These findings have important implications for assessing carbon emissions from arid and semi-arid grasslands under global change. Considering that the effects of increased precipitation and N deposition on shrub-encroached steppe (especially severely encroached steppe) were different from those of typical steppe, the stage of shrub encroachment should be fully considered when constructing carbon cycle models to accurately evaluate the carbon emissions of degraded grassland
Highly efficient removal of patulin using immobilized enzymes of Pseudomonas aeruginosa TF-06 entrapped in calcium alginate beads
No full textPatulin is a toxic secondary metabolite produced by several moulds, which contaminates fruits and their products posing serious threats to human health. Though several microorganisms and enzymes have been reported to effectively degrade patulin, separation of them from fruit juice challenges the commercial applications. Here, a Pseudomonas aeruginosa strain TF-06 was isolated, its patulin degradation mechanism and optimum conditions for enzyme immobilization were investigated. The results indicated that TF-06 could degrade patulin into noncytotoxic E/Z-ascladiol mainly by the activity of intracellular enzymes. For easy separation of enzymes, calcium alginate was selected for immobilization of intracellular enzymes from TF-06. The immobilized enzyme beads were effective in detoxification of patulin in apple juice. The mitigation rate was reached 95%, while there was no negative effect on juice quality. The study provides a promising way to resolve the issue of enzyme separation during mycotoxin biological detoxification in fruit juice
A Ca2+-sensor switch for tolerance to elevated salt stress in Arabidopsis
No full textExcessive Na+ in soils inhibits plant growth. Here, we report that Na+ stress triggers primary calcium signals specifically in a cell group within the root differentiation zone, thus forming a sodium-sensing niche in Arabidopsis. The amplitude of this primary calcium signal and the speed of the resulting Ca2+ wave dose-dependently increase with rising Na+ concentrations, thus providing quantitative information about the stress intensity encountered. We also delineate a Ca2+-sensing mechanism that measures the stress intensity in order to mount appropriate salt detoxification responses. This is mediated by a Ca2+-sensor-switch mechanism, in which the sensors SOS3/CBL4 and CBL8 are activated by distinct Ca2+-signal amplitudes. Although the SOS3/CBL4-SOS2/CIPK24-SOS1 axis confers basal salt tolerance, the CBL8-SOS2/CIPK24-SOS1 module becomes additionally activated only in response to severe salt stress. Thus, Ca2+-mediated translation of Na+ stress intensity into SOS1 Na+/H+ antiporter activity facilitates fine tuning of the sodium extrusion capacity for optimized salt-stress tolerance
Controls of Initial Wood Decomposition on and in Forest Soils Using Standard Material
No full textForest ecosystems sequester approximately half of the world's organic carbon (C), most of it in the soil. The amount of soil C stored depends on the input and decomposition rate of soil organic matter (OM), which is controlled by the abundance and composition of the microbial and invertebrate communities, soil physico-chemical properties, and (micro)-climatic conditions. Although many studies have assessed how these site-specific climatic and soil properties affect the decomposition of fresh OM, differences in the type and quality of the OM substrate used, make it difficult to compare and extrapolate results across larger scales. Here, we used standard wood stakes made from aspen (Populus tremuloides Michx.) and loblolly pine (Pinus taeda L.) to explore how climate and abiotic soil properties affect wood decomposition across 44 unharvested forest stands located across the northern hemisphere. Stakes were placed in three locations: (i) on top of the surface organic horizons (surface), (ii) at the interface between the surface organic horizons and mineral soil (interface), and (iii) into the mineral soil (mineral). Decomposition rates of both wood species was greatest for mineral stakes and lowest for stakes placed on the surface organic horizons, but aspen stakes decomposed faster than pine stakes. Our models explained 44 and 36% of the total variation in decomposition for aspen surface and interface stakes, but only 0.1% (surface), 12% (interface), 7% (mineral) for pine, and 7% for mineral aspen stakes. Generally, air temperature was positively, precipitation negatively related to wood stake decomposition. Climatic variables were stronger predictors of decomposition than soil properties (surface C:nitrogen ratio, mineral C concentration, and pH), regardless of stake location or wood species. However, climate-only models failed in explaining wood decomposition, pointing toward the importance of including local-site properties when predicting wood decomposition. The difficulties we had in explaining the variability in wood decomposition, especially for pine and mineral soil stakes, highlight the need to continue assessing drivers of decomposition across large global scales to better understand and estimate surface and belowground C cycling, and understand the drivers and mechanisms that affect C pools, CO2 emissions, and nutrient cycles
Spatial phylogenetics of the Chinese angiosperm flora provides insights into endemism and conservation
No full textThe flora of China is well known for its high diversity and endemism. Identifying centers of endemism and designating conservation priorities are essential goals for biodiversity studies. However, there is no comprehensive study from a rigorous phylogenetic perspective to understand patterns of diversity and endemism and to guide biodiversity conservation in China. We conducted a spatial phylogenetic analysis of the Chinese angiosperm flora at the generic level to identify centers of neo- and paleo-endemism. Our results indicate that: (i) the majority of grid cells in China with significantly high phylogenetic endemism (PE) were located in the mountainous regions; (ii) four of the nine centers of endemism recognized, located in northern and western China, were recognized for the first time; (iii) arid and semiarid regions in Northwest China were commonly linked to significant PE, consistent with other spatial phylogenetic studies worldwide; and (iv) six high-priority conservation gaps were detected by overlaying the boundaries of China's nature reserves on all significant PE cells. Overall, we conclude that the mountains of southern and northern China contain both paleo-endemics (ancient relictual lineages) and neo-endemics (recently diverged lineages). The areas we highlight as conservation priorities are important for broad-scale planning, especially in the context of evolutionary history preservation
Natural products for infectious microbes and diseases: an overview of sources, compounds, and chemical diversities
No full textAs coronavirus disease 2019 (COVID-19) threatens human health globally, infectious disorders have become one of the most challenging problem for the medical community. Natural products (NP) have been a prolific source of antimicrobial agents with widely divergent structures and a range vast biological activities. A dataset comprising 618 articles, including 646 NP-based compounds from 672 species of natural sources with biological activities against 21 infectious pathogens from five categories, was assembled through manual selection of published articles. These data were used to identify 268 NP-based compounds classified into ten groups, which were used for network pharmacology analysis to capture the most promising lead-compounds such as agelasine D, dicumarol, dihydroartemisinin and pyridomycin. The distribution of maximum Tanimoto scores indicated that compounds which inhibited parasites exhibited low diversity, whereas the chemistries inhibiting bacteria, fungi, and viruses showed more structural diversity. A total of 331 species of medicinal plants with compounds exhibiting antimicrobial activities were selected to classify the family sources. The family Asteraceae possesses various compounds against C. neoformans, the family Anacardiaceae has compounds against Salmonella typhi, the family Cucurbitacea against the human immunodeficiency virus (HIV), and the family Ancistrocladaceae against Plasmodium. This review summarizes currently available data on NP-based antimicrobials against refractory infections to provide information for further discovery of drugs and synthetic strategies for anti-infectious agents
Great granny still ruling from the grave: Phenotypical response of plant performance and seed functional traits to salt stress affects multiple generations of a halophyte
No full textEnvironmental changes, for example, in rainfall and land use, lead to changes in the environment experienced by subsequent generations of plant species. Environmental conditions of maternal plants can influence the fitness and phenotypes of subsequent generations via non-genetic mechanisms: transgenerational plasticity (TGP). However, relevant empirical evidence remains scarce and ambiguous. What are the adaptive consequences of TGP for plants in the face of environmental change? For how many generations does the TGP effect remain? We tried to answer these questions by measuring life-history traits and reproductive characteristics of progeny plants of the diaspore-heteromorphic annual halophyte Atriplex centralasiatica in a 3-year TGP experiment covering F0, F1 and F2 and partly F3. Plants from diaspore types A (low dispersal and high germination ability) and C (high dispersal and low germination ability) were grown in favourable versus stressful salinities over three generations in a fully factorial design. Transgenerational plasticity of plants grown in favourable versus stressful salinities decreased from F2 -> F1 -> F0. Compared to the favourable condition, the stressful condition decreased the length of the vegetative period, increased the length of reproductive time, reproductive allocation and progeny diaspore size. Salinity tolerance and phenotypic plasticity were higher in plants from diaspore A than in those from diaspore C. In the stressful condition, plants produced less plant biomass, larger diaspores, a higher proportion of diaspore C, but lower proportion of diaspore A. Production of the proportion of diaspore C increased with increase in number of previous generations that experienced stress. The stress experience of the great-great grandmother (F0) continued into the lower A:C ratio of the F3 diaspores. Synthesis. Our findings provide evidence for the 'escape strategy' of A. centralasiatica: TGP could spread the risk of environmental adversity by delaying seed germination temporally and broadening seed dispersal spatially, thus allowing plants to cope with environmental heterogeneity. Specifically, the trade-off in reproductive allocation between diaspores A and C enables plants to develop divergent strategies. New research should reveal the extent to which wide-ranging taxa can benefit from TGP and whether even (great)-great grandmother might be the starting point of TGP
Contrasting nitrogen cycling between herbaceous wetland and terrestrial ecosystems inferred from plant and soil nitrogen isotopes across China
No full textUnderstanding nitrogen (N) cycling in different ecosystems is crucial to predicting and mitigating the global effects of altered N inputs. Although wetlands have always been assumed to differ largely from terrestrial ecosystems in N cycling, evidence from direct comparison from the field along wide environmental gradients is lacking. Here, we hypothesized strong coupling of plant and soil delta N-15 in terrestrial ecosystems due to lower N inputs and losses but weak coupling of plant and soil delta N-15 in wetlands because of higher N inputs and losses. We performed a large-scale field investigation on 26 pairs of herbaceous wetland and terrestrial sites across China covering 21 degrees of latitude and determined natural abundance of nitrogen isotopes (delta N-15) in soils and leaves of 346 dominant and subordinate plant species. We analysed the relationships between leaf and soil delta N-15 and their drivers including plant functional types in these two types of ecosystems. Plant functional types including mycorrhizal type and N-2-fixing status had consistently significant influences on leaf delta N-15 in herbaceous wetland and terrestrial ecosystems. Leaf delta N-15 increased significantly with soil delta N-15 within and across mycorrhizal types in both ecosystems, and, as hypothesized, the relationships were stronger and steeper in terrestrial than in wetland ecosystems. Moreover, leaf and soil delta N-15 were positively and significantly correlated within both N-2-fixers and non-N-2-fixers in terrestrial ecosystems and within only non-N-2-fixers in wetlands. At the community level, we also found more highly significant relationships between leaf and soil delta N-15 in terrestrial than in wetland ecosystems. Besides plant functional types, climatic and soil factors contributed to the variation in leaf delta N-15 in both ecosystems. Synthesis. Weaker relationships between plant and soil delta N-15 in wetlands at species and community levels support the hypothesis that larger N inputs and losses lead to weaker coupling in the plant-soil systems in wetlands than in terrestrial ecosystems. This provides strong evidence from a large spatial scale for contrasting N cycling in these two types of ecosystems regardless of plant functional type in terms of nutrient uptake strategy. Our findings add to our predictive power of ecosystem N dynamics under environmental changes, for example, land-use changes and elevated N inputs
Deciphering the contributions of spectral and structural data to wheat yield estimation from proximal sensing
No full textAccurate, efficient, and timely yield estimation is critical for crop variety breeding and management optimization. However, the contributions of proximal sensing data characteristics (spectral, temporal, and spatial) to yield estimation have not been systematically evaluated. We collected long-term, hyper temporal,and large-volume light detection and ranging (LiDAR) and multispectral data to (i) identify the best machine learning method and prediction stage for wheat yield estimation, (ii) characterize the contribution of multisource data fusion and the dynamic importance of structural and spectral traits to yield estimation, and (iii) elucidate the contribution of time-series data fusion and 3D spatial information to yield estimation. Wheat yield could be accurately (R-2 = 0.891) and timely (approximately-two months before harvest) estimated from fused LiDAR and multispectral data. The artificial neural network model and the flowering stage were always the best method and prediction stage, respectively. Spectral traits (such as CIgreen) dominated yield estimation, especially in the early stage, whereas the contribution of structural traits (such as height) was more stable in the late stage. Fusing spectral and structural traits increased estimation accuracy at all growth stages. Better yield estimation was realized from traits derived from complete 3D points than from canopy surface points and from integrated multi-stage (especially from jointing to heading and flowering stages) data than from single-stage data. We suggest that this study offers a novel perspective on deciphering the contributions of spectral, structural, and time-series information to wheat yield estimation and can guide accurate, efficient, and timely estimation of wheat yield.(C) 2022 Crop Science Society of China and Institute of Crop Science, CAAS. Production and hosting by Elsevier B.V