Effect Of Altitude Research Articles

Effect of altitude on COVID-19 mortality rate and case incidence in Peru, the country with the highest cumulative mortality rate worldwide

Effect of altitude on COVID-19 mortality rate and case incidence in Peru, the country with the highest cumulative mortality rate worldwide

The effect of high altitude on ephedrine content and metabolic variations in two species of Ephedra.

Ephedra is an important plant in Chinese medicine; however, there are few reports on two species of Ephedra which are distributed at high altitudes from 3000 to 5200 meters. We collected a total of 84 individuals representing five Ephedra gerardiana and nine Ephedra saxatilis populations respectively located from 3158 to 5200 meters altitude, and determined the relative content of 213 metabolites using UHPLC-MS/MS (Ultra-High-Performance Liquid Chromatography-tandem mass spectrometry). 37 Chemical compositions were annotated using the KEGG (Kyoto Encyclopaedia of Genes and Genomes) database. From the top five significant enrichments in metabolic KEGG pathway analysis, we found a total of 166 compounds belonging to phenylpropanoids, 123 flavonoids, 67 metabolites carried by ABC transporters, and 61 in purine metabolism. We identified the top 8 altitude-related compounds in two species. Ephedrine and pseudoephedrine were found to be associated with altitude in both E. saxatilis and E. gerardiana. To verify which environmental factors influenced the metabolic content, the soil moisture and temperature of each population site were collected, and quantitative analysis of ephedrine and pseudoephedrine was performed using UHPLC-MS (Ultra-High-Performance liquid chromatography-tandem mass spectrometry). After detection, soil moisture ranged from 0.074 to 0.177 mm3/mm3, and temperature ranged from 9.7°C to 23.9°C. The content of ephedrine ranged from (0.84 ± 0.49)% to (2.01 ± 0.41)% in E. saxatilis, which was positively correlated with soil moisture; the content of pseudoephedrine ranged from (0.72 ± 0.45)% to (1.11 ± 0.57)% and was negatively correlated with soil moisture. In contrast to these results, in E. gerardiana, the content of ephedrine and pseudoephedrine was negatively correlated with soil moisture. Furthermore, the trends of alkaloid contents in two kinds of Ephedra were similar when the temperature was lower than 17°C even if the sum was various. With the increase in soil moisture and temperature, the total alkaloid content of E. saxatilis was higher than that of E. gerardiana. When the soil moisture was lower, the alkaloid content of the two Ephedra species was higher. These results provide useful data for the future separation of new compounds, and for seed homogeneous growth to determine artificial breeding of Ephedra located at high altitudes.

Factors Affecting Carotid Artery Stenosis in the Elderly Living at High Altitudes.

Factors affecting carotid artery stenosis have been generally investigated. However, considering the protective effect of altitude, studies on elderly individuals at high altitudes are few. Our aim is to investigate the systematic adaptive changes caused by high-altitude exposure through the causes of carotid artery stenosis. Carotid Doppler ultrasound was performed on 250 patients over the age of 50 years. The patients' age, gender, height, weight, smoking history, place of residence, and presence of comorbidities were questioned. Those with diabetes, hypertension, hyperlipidemia, and coronary disease were excluded from the study. Those who did not reside at high altitudes were excluded from the study. One hundred and thirty-five patients were included in the study. Carotid artery Doppler findings and biochemical parameters were recorded. Factors affecting stenosis in the carotid arteries were compared. In our study, the factors affecting carotid stenosis were determined to be age, gender, presence of plaque, plaque type, and mean carotid intima-media thickness (CIMT). The mean CIMT of the patients was calculated as 0.71±0.14 mm. The mean CIMT measurement level was significantly higher in patients with plaque in the carotid artery (p<0.05). According to receiver operating characteristic curves, CIMT values higher than 0.72 mm increase plaque and stenosis formation in the common carotid artery (CCA) and internal carotid artery (ICA) in elderly people living at high altitudes (p<0.05, area under the curve [AUC]: 0.71-0.83). The most important factors affecting carotid stenosis in individuals living at high altitudes are age, gender, CIMT, plaque, and plaque type. When soft plaques were detected, the risk of stenosis was found to be higher than in calcific plaques. Additionally, the number of factors affecting stenosis was greater on the left (ICA). This suggests that the left carotid system is more vulnerable. It can be said that in elderly individuals living at high altitudes, a CIMT higher than 0.72 mm is a cutoff value in the presence of plaque and stenosis in the carotid arteries.

Insight into the effect of cultivar and altitude on the identification of EnshiYulu tea grade in untargeted metabolomics analysis

The accurate identification of tea grade is crucial to the quality control of tea. However, existing methods lack sufficient generalization ability in identifying tea grades due to the effect of temporal and spatial factors. In this study, we analyzed the effect of cultivar and altitude on EnshiYulu (ESYL) tea grades and established a robust model to evaluate their quality. Principal component analysis (PCA) revealed that differences in variety and elevation can mask grade differences. Orthogonal projection to latent structure-discriminant analysis (OPLS-DA) was used for grade identification of samples from different altitudes. For ESYL tea samples above and below 800 m altitude, 75 and 35 grade differentiated metabolites were discovered, with 14 common differentiated metabolites. Based on reconstructed OPLS-DA models, the grades of multi-altitude sources ESYL were discriminated with a rate > 85%. These results demonstrate the potential of a grade discrimination model based on common differential metabolites, which exhibits generalization ability.

Adaptive response of Siberian roe deer Capreolus pygargus to climate and altitude in the temperate forests of South Korea

Understanding climatic effect on wildlife is essential to prediction and management of climate change's impact on the ecosystem. The climatic effect can interact with other environmental factors. This study was aimed to determine effects of climate and altitude on Siberian roe deer Capreolus pygargus activity in temperate forests of South Korea. We conducted camera trapping to investigate roe deer's activity level from spring to fall. Logistic regressions were used to determine effects of diel period, temperature, rain, and altitude on the activity level. A negative relationship was noted between temperature and the activity level due to thermoregulatory costs. Roe deer activity exhibited nocturnal and crepuscular patterns during summer and the other seasons, respectively, possibly due to heat stress in summer. In addition, the effect of temperature differed between high‐ and low‐altitude areas. In low‐altitude areas, temperature affected negatively the activity level throughout the study period. Conversely, in high‐altitude areas, temperature affected activity level only in summer and early fall. Lower temperatures in higher altitudes favoured roe deer activity, resulting in roe deer's preference towards higher altitude areas. However, roe deer's movement toward lower altitudes was observed in summer. Reduced heat stress by changing activity pattern allowed them to access lower altitude areas with greater resource availability during summer. This study revealed how roe deer activity varied across seasons and altitudes, considering the interactions among weather, microclimate and resource availability. It provides insight into how montane species adapt to various climatic conditions, and this could have important implications for wildlife management and conservation efforts.

Influence of altitude, slope, and waterway characteristics on the occurrence of slow-moving landslides in South Korea

Forest soil sediment disasters, categorized as landslides, slow-moving landslides (land creep), and debris flows, result in destruction of forests and properties, loss of life, and damage to infrastructures. Therefore, it is imperative to evaluate factors that cause slow-moving landslides and establish a national-level hazard information system. In this study, we used geographic information system (GIS) to investigate the difference between landslides and slow-moving landslides by overlapping and analyzing landslide hazard map with slow-moving landslide sites. Slow-moving landslide areas (SLAs) and non-SLAs were characterized to compare the effects of altitude and slope in slow-moving landslide events. Finally, we performed a hydrographical analysis of waterways to compare the SLAs and non-SLAs. Grade 3 slow-moving landslide sites were found to be the most prevalent among all landslide hazard grades (1–5), including those in regions outside the specified grades. The altitude and slope of SLAs were 5 m higher and 1° steeper than those of non-SLAs, respectively. The waterways in non-SLAs (205.4 m) were longer than those in SLAs (85.2 m). Our study highlights the importance of altitude, slope, and waterways as triggers for slow-moving landslides and provides an empirical basis for establishing national hazard information systems for these events.

Does altitude have an effect on stroke mortality and hospitalization risk? A comprehensive evaluation of United States data

BackgroundGlobally, stroke is a leading cause of death among people over 50 years of age. In the United States alone, over 150,000 people die due to stroke every year. Environmental factors such as altitude may play a role in these outcomes; however, their effects have not yet been comprehensively explored. The objective of this study is to evaluate the effect of altitude along with other covariates on stroke mortality and hospitalization rates in adults.MethodsThis study utilized altitude, stroke mortality and hospitalization rates; antihypertensive and cholesterol-lowering medication usage; smoking prevalence; and sociodemographic data (MH-SVI) obtained from government databases for 3,141 counties in the United States from 2018 to 2020. Data were analyzed using generalized additive models with and without adjustments for covariates.ResultsUnadjusted models show that altitude has a comparable significant negative effect on mortality rates for Black and white populations. When including all covariates, altitude continues to have a significant protective effect against stroke fatalities in white populations (retaining 26.6 and 53.8% of the effect magnitude for cardiovascular disease (CVD) and stroke mortality, respectively), a non-significant effect in the Black population, and a detrimental effect in Hispanic and Asian Pacific populations for CVD mortality (a 21.6 and 39.1% effect increase, respectively).ConclusionOur findings add to the growing body of evidence that environmental factors add to disparities between racial groups and play a significant role in CVD and stroke mortality. The effect of altitude is comparable in size to that of smoking, medication usage, and social determinants of health.

The effects of altitude and rearing period on some characteristics of honey bee queens, Apis mellifera caucasica Gorbachev, 1916 (Hymenoptera: Apidae)

In the study, some characteristics of honey bee queens, Apis mellifera caucasica Gorbachev, 1916 (Hymenoptera: Apidae), reared at two different altitudes (140 m vs 920 m) and three rearing seasons (May, June-I, June-II) in 2019-2020 were examined in Ordu. These are larvae grafting, length of the queen cell, weight of queens at various periods, and spermathecae parameters of queens. One-day old 50 larvae were grafted at each period and altitude. The effect of period and period*altitude interaction on the weight at emergence of queen was significant (p&amp;lt;0.001) while the effect of altitude and year was nonsignificant. Weights at emergence of queens were lower in May at high altitudes and in June-II at low altitudes. The effects of year, period and altitude were significant (p&amp;lt;0.001) in the terms of the diameter and volume of the spermathecae, and the number of spermatozoa in the spermathecae. When the two-year data was evaluated together, the number of spermatozoa in the spermathecae was higher in the queen bees reared in May. It is recommended to pay attention to the period and altitude when pollen and nectar flow is intense in queen rearing in Ordu and similar climatic conditions.

The Effects of Altitude on Fruit Characteristics, Nutrient Chemicals, and Biochemical Properties of Walnut Fruits (Juglans regia L.)

This study aimed to investigate changes in fruit characteristics, total phenolics, total antioxidant capacity, organic acids, sugar content, and fatty acid composition in ten walnut genotypes and three cultivars grown at different altitudes under Mediterranean climate conditions. At altitudes of 500 m and 1200 m, total phenolics ranged between 237.51 and 412.96 mg GAE/100 g dw and 234.94 and 392.31 mg GAE/100 g dw, respectively. According to DPPH radical inhibition, the total antioxidant capacity varied between 47.65% and 64.99% at an altitude of 500 m and between 57.76% and 68.92% at an altitude of 1200 m. The oil content demonstrated variations between 53.44% and 76.17% at an elevation of 500 m and between 43.11% and 67.03% at an altitude of 1200 m. At both 500 m and 1200 m altitudes, linoleic acid emerged as the predominant fatty acid and ranged from 58.82% to 62.44% at 500 m altitude and from 57.33% to 59.38% at 1200 m altitude. Notably, malic acid was identified as the primary organic acid, with concentrations ranging from 1.35% to 7.33% at both altitudes. In conclusion, this study demonstrates that walnut seeds are abundant in oil, protein, total phenolics, antioxidants, and fatty acids, with variations influenced by the cultivar or genotype and notably affected by altitude.

Tropical high altitude and severe asthma in adults: house dust mite sensitization and phenotypic distribution

Background There is a lack of information on house dust mite (HDM) sensitization and phenotype distribution in patients with severe asthma (SA) living permanently at high-altitude (HA) in tropical regions, which may be different. Objective The aim of this study was to characterize adults with SA in a tropical high altitude city (2,640 m): Bogotá, Colombia. Material and Methods This observational cross-sectional study included severe asthmatic outpatients (n = 129) referred to the ASMAIRE program of the Fundación Neumológica Colombiana in Bogotá (2,640 m). Clinical history, spirometry, total IgE, blood eosinophils, and skin prick test (SPT), including HDM allergens, were performed. Phenotype definitions: Allergic/atopic (AA): IgE ≥100 IU/mL and/or at least one positive SPT; eosinophilic (EOS): blood eosinophils ≥300 cells/µL; type 2-high: AA and/or EOS phenotype; type 2-low: non-AA/non-EOS phenotype (IgE <100 IU/mL, negative SPT, and blood eosinophils <300 cells/µL). Results A total of 129 adults with SA were included, 79.8% female. Phenotype distribution: AA: 61.2%; EOS: 37.2%; type 2-high: 72.1%; type 2-low: 27.9%. Among AA patients, HDM sensitization was present in 87% and 34.9% were non-eosinophilic. There was a significant overlap between the phenotypes. Conclusions In contrast to non-tropical high-altitude regions, we found a high frequency of HDM sensitization in patients with AA phenotype living in a tropical high-altitude city. We also found a discrete lower frequency of EOS phenotype with no other significant differences in the phenotypic distribution compared to that described at low altitudes. We propose that tropical location may modify the effect of high altitude on HDM concentrations and allergenicity.

Cellular localizability of unmanned aerial vehicles

To enable pervasive applications of cellular-connected unmanned aerial vehicles (UAVs), localization plays a key role. The successful reception of localization signals from multiple base stations (BSs) is the first step to localize targets, which is called cellular localizability. In this paper, we propose an analytical framework to characterize the B-localizability of UAVs, which is defined as the probability of successfully receiving localization signals above a certain signal-to-interference plus noise ratio (SINR) level from at least B ground BSs. Our framework considers UAV-related system parameters in a three-dimensional environment and provides a comprehensive insight into factors affecting localizability such as distance distributions, path loss, interference, and received SINR. We perform simulation studies to explore the relationship between localizability and the number of participating BSs, SINR requirements of the received localization signals, air-to-ground channel characteristics, and network coordination. We also formulate an optimization problem to maximize localizability and investigate the effects of UAV altitude in different scenarios. Our study reveals that in an urban macro environment, the effectiveness of cellular network-based localization increases with altitude, with localizability reaching 100% above 60 meters. This finding indicates that utilizing cellular networks for UAV localization is a viable option.

Spatiotemporal Variation of Evapotranspiration and Its Driving Factors in the Urumqi River Basin

Evapotranspiration (ET) is a key indicator of arid and semi-arid ecosystem processes and hydrological cycles. The study of basin-scale ET characteristics and drivers can provide a better understanding of regional water balance and energy cycles. This study used the Pixel Information Expert Engine platform based on MODIS (MOD16A2) data to extract the separate spatial and temporal characteristics of interannual and seasonal ET in the Urumqi River Basin in Xinjiang, China, over a 20-year period, from 2000 to 2020, and to analyze the influence of land-use data and altitude on ET in the basin. The average interannual ET in the watershed has had an increasing trend over the past two decades, varying from 126.57 mm to 247.66 mm, with the maximum ET in July and the minimum in December. On the seasonal scale, the ET trend is greatest in summer, followed by spring, and it is the least in winter. Spatially, the surface ET in the Urumqi River Basin is generally high in the upstream area and low in the downstream area, with the average multi-year ET throughout the basin falling within the range of 22.74–479.33 mm. The average ET for each type of land use showed that forest land had the highest ET and unused land the lowest. Analysis found that the effect of altitude on ET was more pronounced, with a significant increase in ET as altitude increases. Analysis of the drivers of ET change from 2000 to 2020 using the Optimal Parameters-based Geographical Detector model (OPGD) showed that the natural factors that had the greatest influence were, in descending order, temperature &gt; vegetation cover &gt; precipitation. Among the interacting factors, vegetation index with temperature, elevation, and precipitation and land use with elevation had a relatively greater influence on ET in the basin, and the effects of interacting factors were all greater than those of single factors.

Impacts of Drone Flight Altitude on Behaviors and Species Identification of Marsh Birds in Florida

Unmanned aerial vehicles (hereafter drones) are rapidly replacing manned aircraft as the preferred tool used for aerial wildlife surveys, but questions remain about which survey protocols are most effective and least impactful on wildlife behaviors. We evaluated the effects of drone overflights on nontarget species to inform the development of a Florida mottled duck (MODU; Anas fulvigula fulvigula) survey. Our objectives were to (1) evaluate the effect of flight altitude on the behavior of marsh birds, (2) evaluate the effect of altitude on a surveyor’s ability to identify the species of detected birds, and (3) test protocols for upcoming MODU surveys. We flew 120 continuously moving transects at altitudes ranging from 12 to 91 m and modeled variables that influenced detection, species identification, and behavior of nontarget species. Few marsh birds were disturbed during drone flights, but we were unable to confidently detect birds at the two highest altitudes, and we experienced difficulties identifying the species of birds detected in video collected at 30 m. Our findings indicate that MODUs could be surveyed at altitudes as low as 12–30 m with minimal impact to adjacent marsh birds and that larger-bodied nontarget marsh species can be identified from videos collected during MODU drone surveys.

Effect of altitude and spatial heterogeneity on the host-parasite relationship in anurans from a remnant humid forest in the brazilian semiarid.

In the present study, we investigated the effect of habitat heterogeneity, elevation gradient, and phylogenetic distance of host species on the abundance and richness of anuran endoparasites, assuming that parasites follow the distribution of their hosts independently of environmental variation. We collected 192 anurans distributed in three altitude ranges: 100-200m, 400-500m, and 700-800m. We performed discriminant principal component analysis to analyze the interrelationships between environmental heterogeneity and the distribution of parasite and host species in the formation of species groups in each altitude range. We estimated the niche width and parasite overlap, using host species as a variable, and assessed whether parasite abundance is more influenced by historical (distance host phylogeny) or ecological effects in each altitude category and overall. Finally, we use network analyses to understand how interactions between parasites and hosts are formed along the altitude gradient. We found 22 parasite species, and the overall prevalence of infection was 74%. In our study, we did not identify environmental (altitude gradients and heterogeneity) or phylogenetic effects acting on the parasite species diversity. Overall, our results suggest that the parasites are distributed following the dispersal of their hosts and are dispersed among most anuran species.

Satellite-Based Distribution of Inverse Altitude Effect of Global Water Vapor Isotopes: Potential Influences on Isotopes in Climate Proxies

The widely-distributed altitude effect of stable isotopes in meteoric water, i.e., the negative correlation between stable hydrogen (or oxygen) isotope compositions and altitude, is the theoretical basis of isotope paleoaltimetry in climate proxies. However, as many recent local observations have indicated, the inverse altitude effect (IAE) in meteoric water does exist, and the regime controlling IAE is still unclear on a global scale. Based on a remote sensing product of the Infrared Atmospheric Sounding Interferometer (IASI), we examined the global frequency of IAE in water vapor isotopes, and the possible influences on isotopes in precipitation and climate proxies. According to the satellite-based δD values in water vapor at 2950 m and 4220 m above sea level, frequent IAEs are observed on a daily scale in North Africa, West and Central Asia, and North America, and IAEs are more likely to occur during the daytime than during the nighttime. We also converted water vapor δD to precipitation δD via equilibrium fractionation and then analyzed the potential presence of IAE in precipitation, which is more associated with climate proxies, and found that the spatial and temporal patterns of water vapor can be transferred to the precipitation. In addition, different thresholds of δD difference were also tested to understand the impact of random errors. The potential uncertainty of the changing isotope and altitude gradient should be considered in paleo-altitude reconstructions.

More severe initial manifestations and worse short-term functional outcome of intracerebral hemorrhage in the plateau than in the plain

Intracerebral hemorrhage (ICH) is one of the most devastating forms of stroke. However, studies on ICH at high altitude are insufficient. We aimed to compare the initial manifestations, imaging features and short-term functional outcomes of ICH at different altitudes, and further explore the effect of altitude on the severity and prognosis of ICH. We retrospectively recruited ICH patients from January 2018 to July 2021 from two centers at different altitudes in China. Information regarding to clinical manifestations, neuroimages, and functional outcomes at discharge were collected and analyzed. Association between altitude and initial severity, neuroimages, and short-term prognosis of ICH were also investigated. A total of 724 patients with 400 lowlanders and 324 highlanders were enrolled. Compared with patients from the plain, those at high altitude were characterized by more severe preliminary manifestations (P < 0.0001), larger hematoma volume (P < 0.001) and poorer short-term functional outcome (P < 0.0001). High altitude was independently associated with dependency at discharge (adjusted P = 0.024), in-hospital mortality (adjusted P = 0.049) and gastrointestinal hemorrhage incidence (adjusted P = 0.017). ICH patients from high altitude suffered from more serious initial manifestations and worse short-term functional outcome than lowlanders. Control of blood pressure, oxygen supplementation and inhibition of inflammation may be critical for ICH at high altitude.

The distribution of diatom assemblages with the effects of environmental parameters and ecological status assessment based on diatom indices in the lentic systems of the Akarçay and Asi Basins (Türkiye).

In order to detect the effects of different stressors on the littoral diatom assemblages and biodiversity of the lentic systems in two different basins in Türkiye, 15 lentic systems in the Akarçay and Asi basins were sampled three times (spring, summer, and fall) for littoral diatoms and environmental variables. The biological assessment of these sites was also evaluated using 9 different river and lake diatom indices. Based on the total phosphorus (TP), total nitrogen (TN), electrical conductivity (EC), salinity (SAL) values, and dominant diatom species, three lentic systems in Akarçay Basin (Lake Eber, 26 Ağustos Pond, and Lake Karamık) were more eutrophic and under the pressure of anthropogenic and climatic (precipitation) stressors. Trophic diatom index for lakes (TDIL) showed a higher correlation with TN and TP and was the most effective index in explaining ecological quality in 15 lentic systems. The species richness of diatoms was also negatively affected by EC and SAL values. The lentic systems of the two basins were separated from each other based on the species composition and the distribution of the dominant species with the effect of altitude (ALT). Considering the distribution of diatom assemblage of the lentic systems in these two basins, anthropogenic, climatic, and geographical factors have become prominent to shape the diatom community structure.

Association of co-exposure to metal(loid)s during pregnancy with birth outcomes in the Tibetan plateau

Maternal metal (loid)s exposure has been related to birth outcomes but the results are still inconclusive. Most previous studies have discussed the single metal (loid)s, neglecting the scene of co-exposure. We examined the associations of both single metal (loid)s and metal mixtures with birth outcomes in a birth cohort from the Tibetan Plateau, including body weight, body length, head circumference, small for gestational age (SGA), and Ponderal index (PI). In our analysis of 1069 women, we measured 29 metal (loid)s in urine samples in the third trimester. The associations of single metal (loid)s with categorical or continuous birth outcomes were evaluated using a generalized linear mixed-effects model or linear mixed-effects model, respectively. The least absolute shrinkage and selection operator, Bayesian kernel machine, and Quantile g-computation regression were used to explore the joint association. We also evaluated the interactive effects of ethnicity and altitude on the effect of metal (loid)s on birth outcomes. Copper (Cu) concentration in maternal urine was positively associated with SGA, birth weight, birth length, and head circumference in the single pollutant models. For instance, Cu was associated with an increased risk of SGA [OR (95% CI) = 1.56 (1.23, 1.97); P < 0.001]. We didn't find significant joint association of metal mixtures with birth outcomes except a positive association between the mixture of Cu, Magnesium (Mg), and Iron (Fe) with the risk of SGA when the exposure level was above its 80th percentile, and Cu dominated the adverse association in a non-linear manner. Living altitude modified the associations of Cu with SGA and the positive association was only found in participants living at high altitude. In conclusion, maternal urinary metal (loid)s, especially Cu, was the dominant harmful metal (loid)s when associated with SGA on the Tibetan Plateau.

Response of leaf blade in Zanthoxylum planispinum var. dintanensis to differences altitudes through integrated metabolomics and transcriptomics analysis

To analyze the effects of altitude on Z. planispinum var. Dintanensisin, leaves of samples from different altitudes (H1:1054 m.a.s.l., H2:821 m.a.s.l., H3:645 m.a.s.l.) were collected for integrative analysis of the metabolome and transcriptome in the present study. According to transcriptome data, a total of 9,566 differentially expressed genes (DEGs) were identified from the three sample comparisons (H1 vs. H2, H1 vs. H3, H2 vs. H3). Fewer DEGs were observed in the H2 vs. H3 group than in the other two comparison groups, suggesting that differences in the transcriptome increased with elevation. Most genes were involved in “Biosynthesis of secondary metabolites”, “Plant hormone signal transduction” and “MAPK signaling pathway-plant” based on KEGG enrichment analysis. In total, 423 differential metabolites (DAMs) were determined in the three comparisons (mentioned above) by using metabolomics analysis, of which flavonoids (14.91%) were dominant. Interestingly, more accumulation of terpenoids, aldehydes and esters was observed at higher altitudinal levels, while higher percentages of flavonoids and polyphenols were obtained at lower altitudes based upon K-Means analysis. A unique pathway (p value<0.01) linked to “flavonoid biosynthesis” appeared to have consistent expression patterns in the comparison of H1 vs. H3 based on network analyses of DEGs and DAMs. Notably, regarding the direct products of catalytic reactions, naringenin chalcone, aromadendrin, and naringenin were positively regulated by genes encoding CHS, F3H and CHI, respectively. In addition, the transcription levels of nine candidate genes, including CHI, CHS, CCoAOMT, 2ODDs, ANS, ANR, F3H, DFR and HCT, were confirmed by RT‒qPCR, which were consistent with transcriptional profile data regarding RNA-seq and further demonstrated that these genes involved in flavonoid biosynthesis contribute to the environmental adaptation of the blade in Z. planispinum var. Dintanensis. In summary, our findings represent the first integration of transcriptome data with widely targeted metabolomic data from Z. planispinum var. Dintanensis grown in rocky desertification control areas, which provides novel insights into adaptation to environmental stress. This study has the potential to improve the cultivation and management of Z. planispinum var. Dintanensis through various technologies to gain maximum medicinal production in the future.

The mitochondrial genome of the mountain wooly tapir, Tapirus pinchaque and a formal test of the effect of altitude on the adaptive evolution of mitochondrial protein coding genes in odd-toed ungulates

BackgroundThe harsh conditions of high-altitude environments are known to drive the evolution of physiological and morphological traits in endothermic animals. These conditions are expected to result in the adaptive evolution of protein coding genes encoded in mitochondrial genomes that are vital for the oxidative phosphorylation pathway. In this study, we formally tested for signatures of adaptive evolution on mitochondrial protein coding genes in Tapirus pinchaque and other odd-toed ungulates inhabiting high-elevation environments.ResultsThe AT-rich mitochondrial genome of T. pinchaque is 16,750 bp long. A phylomitogenomic analysis supports the monophyly of the genus Tapirus and families in the Perissodactyla. The ratio of non-synonymous to synonymous substitutions demonstrated that all mitochondrial genes undergo purifying selection in T. pinchaque and other odd ungulates living at high elevations. Over this negative background selection, Branch Models suggested that cox3 and nad6 might be undergoing stronger purifying selection than other mitochondrial protein coding genes. Furthermore, Site Models suggested that one and four sites in nad2 and nad5, respectively, could be experiencing positive selection. However, these results were supported by Likelihood Ratio Tests but not Bayesian Empirical Bayes posterior probabilities. Additional analyses (in DataMonkey) indicated a relaxation of selection strength in nad6, evidence of episodic diversifying selection in cob, and revealed episodic positive/diversifying selection signatures for two sites in nad1, and one site each in nad2 and nad4.ConclusionThe mitochondrial genome of T. pinchaque is an important genomic resource for conservation of this species and this study contributes to the understanding of adaptive evolution of mitochondrial protein coding genes in odd-toed ungulates inhabiting high-altitude environments.