Search Results (17)

Understanding how pollinators adjust their behavior to maximize reproductive success in resource-limited desert ecosystems is a fundamental ecological question. In this study, we investigated X. mongolicus using a combination of field behavioral observations, pollen identification, nutritional analysis, and morphometric measurements to systematically examine interannual variations in its flower visitation spectrum, foraging behavior, bee bread composition, and offspring body size. Our findings reveal a striking contrast: although this species exhibits polyphagy in flower visitation, it shows dietary specialization in larval nutrition—over 92% of the pollen in its bee bread originates from just two leguminous species, A. mongolicus and O. bicolor. Foraging duration increased with rising temperature and humidity, and bees adapted to strong winds by flying close to the ground. Compared with 2024, the bee bread in 2025 had lower fresh weight but higher crude protein content, and offspring body size was larger—likely due to more abundant spring rainfall in 2025, which improved the flowering performance of A. mongolicus. Collectively, these results indicate that this bee species copes with resource uncertainty in desert habitats through flexible foraging range and highly specialized food storage, with its reproductive success closely tied to the nutritional supply of key plants and precipitation patterns. This study highlights the role of precipitation timing in shaping the nutritional foundation of plant–pollinator interactions, providing a scientific basis for the conservation and management of desert pollinators. Full article

Ammopiptanthus mongolicus is a relict species from the ancient Mediterranean of the Tertiary period and the only strong xerophytic evergreen broad-leaved shrub in the central Asian desert. Foliar endophytic and epiphytic bacteria jointly form phyllosphere microorganisms that influence plant health. This study investigated the dynamic changes in foliar endophytic bacterial communities across four leaf growth stages (Young, Mature, Old1, and Old2). Illumina 16S region (V5–V7) amplicon sequencing was used to analyze community composition, function, construction process, and environmental driving factors. The Old1 and Old2 stages were clearly separated from the Young and Mature stages, which demonstrated closer clustering. Community diversity and evenness first increased from the Young to Mature stages, declined at the Old1 stage, and finally reached maximum values at the Old2 stage; richness increased gradually. Total amplicon sequence variant (ASV) numbers, stage-specific ASVs, and their proportion increased with leaf development, whereas the proportion of shared ASVs between adjacent, interval, and all stages decreased. Dominant genera were Rhodococcus (Young), unclassified_f__Comamonadaceae (Mature), Rhodococcus (Old1), and Bacillus (Old2). Co-occurrence networks became progressively simpler, with reduced inter-node and positive connectivity. Functional predictions revealed that chemoheterotrophy and aerobic chemoheterotrophy decreased initially and then increased, with the lowest values at Old1. N, C/P, N/P, and SOD reached maximum at the Old2 stage. P was maximum at the Mature stage. P, C/P, and N/P were significantly positively correlated with the Young stage, N with the Mature stage, and SOD with the Old2 stage (p < 0.05). These findings enhance understanding of the diversity, composition, function, and plant–endophyte relationships in xerophytic relict species, particularly evergreen desert shrubs. Full article

The Ulan Buh Desert represents a quintessential desert ecosystem in the arid northwest of China. As the key factor to maintain the stability of ecosystem, the chemical characteristics of groundwater and its water relationship with vegetation need to be further studied. Through field sampling, hydrochemical analysis, hydrogen and oxygen isotope testing and the Bayesian mixing model (MixSIAR), this study systematically analyzed the chemical characteristics of groundwater, spatial distribution and vegetation water sources in the study area. The results show that the groundwater is predominantly of the Cl⁻–SO₄²⁻ type, with total dissolved solids (TDS) ranging from 0.34 to 9.56 g/L (mean: 2.03 g/L), indicating medium to high salinity and significant spatial heterogeneity. These characteristics are jointly controlled by rock weathering, evaporative concentration, and ion exchange. Soil water isotopes exhibited vertical differentiation: the surface layer (0–20 cm) was significantly affected by evaporative fractionation (δD: −72‰ to −45‰; δ¹⁸O: −9.3‰ to −6.2‰), while deep soil water (60–80 cm) showed isotopic enrichment (δD: −29‰ to −58‰; δ¹⁸O: −6.8‰ to 0.9‰), closely matching groundwater isotopic signatures. Vegetation water use strategies demonstrated depth stratification: shallow-rooted plants such as Reaumuria soongorica and Kalidium foliatum relied primarily on shallow soil water (0–20 cm, >30% contribution), whereas deep-rooted plants such as Nitraria tangutorum and Ammopiptanthus mongolicus predominantly extracted water from the 40–80 cm soil layer (>30% contribution), with no direct dependence on groundwater. Full article

In northern China’s arid and semi-arid regions, evergreen trees demonstrate significant cold tolerance to natural low-temperature stress during winter. However, the metabolic strategies and their associated properties underlying their overwintering adaptation remain incompletely elucidated. This study aims to reveal the metabolic properties of natural low-temperature adaptation strategies in five evergreen trees through metabolomic analysis and to identify key metabolites and their dynamic variation patterns. The GC-TOF-MS platform was used to investigate seasonal differential metabolites in five evergreen trees across January, April, July, and October and further explore core differentially expressed metabolites responsive to low-temperature stress. The results demonstrated that the seasonal changes in the chlorophyll content of five evergreens exhibited distinct patterns, that significant differences were observed between Juniperus sabina L. and Picea meyeri R., Ammopiptanthus mongolicus M., Buxus sinica var. parvifolia M.Cheng, and Pinus tabuliformis C., and that no significant differences were found among the other tree species. A total of 427 metabolites were detected in the metabolome; when assessing seasonal dynamics, it was found that the types of differentially expressed metabolites in the five evergreens underwent significant changes. In spring, the differentially expressed metabolites included some carbohydrates, alcohols, organic acids, and lipids. During summer and autumn, the largest number of differentially expressed metabolites accumulated, mainly including carbohydrates, organic acids, and amino acid compounds. In winter, while Picea meyeri primarily accumulated carbohydrates, the remaining four species mainly accumulated organic acids, along with a small number of alcohols, phenylpropanoids, and polyketides. Three shared carbohydrate metabolites, L-threose, galactinol, and gluconic lactone, were commonly downregulated across all species. Additionally, coniferous trees collectively accumulated 3,6-anhydro-D-galactose, showing downregulation. The KEGG enrichment analysis of winter-accumulated metabolites revealed significant associations with the pentose phosphate pathway, amino acid metabolism, phenylpropanoid biosynthesis, the tricarboxylic acid cycle, and ascorbate–aldarate metabolism pathways. Through comparative analysis with the summer growth season, we ultimately identified the core differentially expressed metabolites of the five evergreens, providing potential metabolic markers for the breeding of cold-tolerant species. In summary, these findings provide critical metabolomic insights into how plants adapt to low temperatures, significantly enhancing our understanding of the metabolic foundations of cold tolerance in evergreen species. Full article

The Gobi Desert is one of the harsh terrestrial ecosystems distributed on the Mongolian Plateau and northwest China. Water is the key restricting environmental factor for the Gobi Desert plants’ growth. Exploring the annual dynamic of water sources for the vulnerable plants in the Gobi Desert helps to understand their adaptation to the arid climate and is fundamental for their conservation, e.g., the vulnerable plant Ammopiptanthus mongolicus (Maxim. ex Kom.) S. H. Cheng. The water source of the dominant and companion shrubs in a Gobi Desert A. mongolicus community was determined by comparing the δD and δ¹⁸O values of their xylem water and different layers of soil water using the MixSIAR model from spring to autumn over two years. The results showed that A. mongolicus mainly utilized 50–150 cm of middle and deep soil water. However, it also used 10 or 25 cm of surface soil water after heavy rains in the early spring and moderate rains in the autumn of 2021 and after heavy rains in the summer of 2022. Three companion shrubs (Nitraria sphaerocarpa Maxim, Caragana korshinskii Kom, and Convolvulus tragacanthoides Turcz.) had similar main water sources, competing for relatively reliable deep soil water with the dominant A. mongolicus during droughts in 2021 and 2022. Moreover, A. mongolicus utilized more deep soil water in 2021 with less rain. However, C. tragacanthoides used more shallow soil water during the growing season of 2022 with more rain. Therefore, four xerophytic shrubs in the A. mongolicus community utilized soil water in different layers based on their ability to adapt to the annual fluctuation of rain in the Gobi Desert. Full article

Background: Ammopiptanthus mongolicus is a rare temperate evergreen shrub with high tolerance to low temperature, and understanding the related gene expression regulatory network can help advance research on the mechanisms of plant tolerance to abiotic stress. Methods: Here, time-course transcriptome analysis was applied to investigate the gene expression network in A. mongolicus under low temperature stress. Results: A total of 12,606 differentially expressed genes (DEGs) were identified at four time-points during low temperature stress treatment, and multiple pathways, such as plant hormones, secondary metabolism, and cell membranes, were significantly enriched in the DEGs. Trend analysis found that the expression level of genes in cluster 19 continued to upregulate under low temperatures, and the genes in cluster 19 were significantly enriched in plant hormone signaling and secondary metabolic pathways. Based on the transcriptome data, the expression profiles of the genes in abscisic acid, salicylic acid, and flavonoid metabolic pathways were analyzed. It was found that biosynthesis of abscisic acid and flavonoids may play crucial roles in the response to low temperature stress. Furthermore, members of the phenylalanine ammonia-lyase (PAL) family in A. mongolicus were systematically identified and their structures and evolution were characterized. Analysis of cis-acting elements showed that the PAL genes in A. mongolicus were closely related to abiotic stress response. Expression pattern analysis showed that PAL genes responded to various environmental stresses, such as low temperature, supporting their involvement in the low temperature response in A. mongolicus. Conclusions: Our study provides important data for understanding the mechanisms of tolerance to low temperatures in A. mongolicus. Full article

Ammopiptanthus mongolicus is an ancient remnant species from the Mediterranean displaying characteristics such as high-temperature tolerance, drought resistance, cold resistance, and adaptability to impoverished soil. In the case of high-temperature tolerance, heat shock transcription factors (HSFs) are integral transcriptional regulatory proteins exerting a critical role in cellular processes. Despite extensive research on the HSF family across various species, there has been no analysis specifically focused on A. mongolicus. In this study, we identified 24 members of the AmHSF gene family based on the genome database of A. mongolicus, which were unevenly distributed over 9 chromosomes. Phylogenetic analysis showed that these 24 members can be categorized into 5 primary classes consisting of a total of 13 subgroups. Analysis of the physical and chemical properties revealed significant diversity among these proteins. With the exception of the AmHSFB3 protein, which is localized in the cytoplasm, all other AmHSF proteins were found to be situated in the nucleus. Comparison of amino acid sequences revealed that all AmHSF proteins contain a conserved DNA-binding domains structure, and the DNA-binding domains and oligomerization domains of the AmHSF gene exhibit conservation with counterparts across diverse species; we investigated the collinearity of AmHSF genes in relation to those of three other representative species. Through GO enrichment analysis, evidence emerged that AmHSF genes are involved in heat stress responses and may be involved in multiple transcriptional regulatory pathways that coordinate plant growth and stress responses. Finally, through a comprehensive analysis using transcriptome data, we examined the expression levels of 24 AmHSFs under 45 °C. The results revealed significant differences in the expression profiles of AmHSFs at different time intervals during exposure to high temperatures, highlighting their crucial role in responding to heat stress. In summary, these results provide a better understanding of the role and regulatory mechanisms of HSF in the heat stress response of A. mongolicus, meanwhile also establishing a foundation for further exploration of the biological functions of AmHSF in the adversity response of A. mongolicus. Full article

Plant cuticular wax forms a hydrophobic structure in the cuticle layer covering epidermis as the first barrier between plants and environments. Ammopiptanthus mongolicus, a leguminous desert shrub, exhibits high tolerances to multiple abiotic stress. The physiological, chemical, and transcriptomic analyses of epidermal permeability, cuticular wax metabolism and related gene expression profiles under osmotic stress in A. mongolicus leaves were performed. Physiological analyses revealed decreased leaf epidermal permeability under osmotic stress. Chemical analyses revealed saturated straight-chain alkanes as major components of leaf cuticular wax, and under osmotic stress, the contents of total wax and multiple alkane components significantly increased. Transcriptome analyses revealed the up-regulation of genes involved in biosynthesis of very-long-chain fatty acids and alkanes and wax transportation under osmotic stress. Weighted gene co-expression network analysis identified 17 modules and 6 hub genes related to wax accumulation, including 5 enzyme genes coding KCS, KCR, WAX2, FAR, and LACS, and an ABCG transporter gene. Our findings indicated that the leaf epidermal permeability of A. mongolicus decreased under osmotic stress to inhibit water loss via regulating the expression of wax-related enzyme and transporter genes, further promoting cuticular wax accumulation. This study provided new evidence for understanding the roles of cuticle lipids in abiotic stress tolerance of desert plants. Full article

The NAC family of transcription factors (TFs) is recognized as a significant group within the plant kingdom, contributing crucially to managing growth and development processes in plants, as well as to their response and adaptation to various environmental stressors. Ammopiptanthus mongolicus, a temperate evergreen shrub renowned for its remarkable resilience to low temperatures and drought stress, presents an ideal subject for investigating the potential involvement of NAC TFs in stress response mechanisms. Here, the structure, evolution, and expression profiles of NAC family TFs were analyzed systematically, and a cold and osmotic stress-induced member, AmNAC24, was selected and functionally characterized. A total of 86 NAC genes were identified in A. mongolicus, and these were divided into 15 groups. Up to 48 and 8 NAC genes were generated by segmental duplication and tandem duplication, respectively, indicating that segmental duplication is a predominant mechanism in the expansion of the NAC gene family in A. mongolicus. A considerable amount of NAC genes, including AmNAC24, exhibited upregulation in response to cold and osmotic stress. This observation is in line with the detection of numerous cis-acting elements linked to abiotic stress response in the promoters of A. mongolicus NAC genes. Subcellular localization revealed the nuclear residence of the AmNAC24 protein, coupled with demonstrable transcriptional activation activity. AmNAC24 overexpression enhanced the tolerance of cold and osmotic stresses in Arabidopsis thaliana, possibly by maintaining ROS homeostasis. The present study provided essential data for understanding the biological functions of NAC TFs in plants. Full article

Shrubs are the main dominant plants in arid desert systems and play an important role in maintaining the biodiversity, ecosystem services and stability of desert ecosystems. Studies have shown that the survival of a large number of shrub species in desert areas under the influence of climate change is significantly threatened, with different species showing different response strategies. To test the tolerance of different shrub species to climate change, this study selected 10 dominant shrub species (ancient relict shrub species and regional endemic shrub species) in the Alashan desert area as the research object. Based on a field survey of species distribution, a species distribution model was developed to simulate the suitable distribution area of shrub species under current conditions and under future climate change scenarios. The distribution changes of ancient relict and regional endemic shrub species under the climate change scenarios were tested, and the tolerance of the two types of shrub to climate change was analyzed. The results showed that under different climate change scenarios, except for Ammopiptanthus mongolicus, the total suitable area of four out of the five relict plants was relatively stable, the potential distribution area of Tetraena mongolica increased, and the future distribution pattern was basically consistent with the current distribution. However, the suitable area of typical desert plants was unstable under different climate change scenarios. Except for Kalidium foliatum, the suitable distribution areas of four out of the five shrubs showed different degrees of reduction, and the distribution location showed significant migration. Based on the research results, climate change will lead to the reduction and displacement of the distribution area of typical desert shrubs, while relict shrubs will be less affected by climate change. This is because, compared to desert species, relict plants have a longer evolutionary history and have developed a wider range of adaptations after experiencing dramatic environmental changes. This study provides a scientific basis for actively responding to the impacts of climate change on desert ecosystems. Full article

The original ‘Green Revolution’ genes are associated with gibberellin deficiency. However, in some species, mutations in these genes cause pleiotropic phenotypes, preventing their application in dwarf breeding. The development of novel genotypes with reduced plant height will resolve this problem. In a previous study, we obtained two dwarf lines, L28 and L30, by introducing the Ammopiptanthus mongolicus (Maxim. ex Kom.) Cheng f. C-repeat-binding factor 1 (AmCBF1) into the upland cotton variety R15. We found that Gossypium hirsutum Tubulin beta-1 (GhTUBB1) was downregulated in L28 and L30, which suggested that this gene may have contributed to the dwarf phenotype of L28 and L30. Here, we tested this hypothesis by silencing GhTUBB1 expression in R15 and found that decreased expression resulted in a dwarf phenotype. Interestingly, we found that repressing AmCBF1 expression in L28 and L30 partly recovered the expression of GhTUBB1. Thus, AmCBF1 expression presented a negative relationship with GhTUBB1 expression in L28 and L30. Moreover, yeast one-hybrid and dual-luciferase assays suggest that AmCBF1 negatively regulates GhTUBB1 expression by directly binding to C-repeat/dehydration-responsive (CRT/DRE) elements in the GhTUBB1 promoter, potentially explaining the dwarf phenotypes of L28 and L30. This study elucidates the regulation of GhTUBB1 expression by AmCBF1 and suggests that GhTUBB1 may be a new target gene for breeding dwarf and compact cultivars. Full article

Ammopiptanthus mongolicus, a traditional ethnic medicinal herb, is a rare broad-leaved evergreen shrub in the arid region of central Asia that can survive under extremely low temperatures during winter. In this study, we investigated the cold stress response of A. mongolicus leaves using physiological and proteomic approaches. Cold stress treatment increased the relative electrolyte leakage, proline, and soluble sugar levels and decreased the chlorophyll content in A. mongolicus leaves. Moreover, 93 differentially abundant proteins (DAPs) were identified using two-dimensional electrophoresis, of which 79 were further confirmed via tandem mass spectrometric analysis. The predicted functions of DAPs were mainly associated with photosynthesis in chloroplasts, reactive oxygen species scavenging, defense, and protein synthesis, folding, and degradation. A. mongolicus chitinase A (AmCHIA) is a cold-induced apoplast protein whose transcription is upregulated under cold, osmotic, high-salinity, and mechanical stresses. Recombinant AmCHIA expressed in Escherichia coli exhibits chitinase activity. Here, AmCHIA expression enhanced the cold tolerance of E. coli cells, suggesting that it may contribute to the cold adaptation of A. mongolicus after cold treatment. The present study not only provides important data for understanding the cold stress responses in plants but also serves as a basis for further exploration of the biological functions of cold-induced proteins in A. mongolicus using genetic approaches. Full article

The ecological indicators for the growth and restoration of A. mongolicus populations are important for grasping the regulatory mechanisms of the biogeochemistry cycle, and for providing basic data for the prediction and evaluation of the evolution characteristics of natural A. mongolicus populations. We conducted studies on the eco-stoichiometric characteristics of natural A. mongolicus in different shrub ages, in order to understand the nutrient limitations for the growth and development of A. mongolicus and the synergy between the soil, leaves and roots, and to explore the C, N and P stoichiometric characteristics on A. mongolicus. The results showed the following: (1) The response of C, N and P stoichiometric characteristics in the leaves, roots and soil to changes in shrub age was not completely consistent. The leaf C content was young shrub> mature shrub> middle age shrub. The C content in the root system and C and N content in the soil showed an upward trend with increasing shrub age. The N and P contents of the root system and the P content of the soil showed a downward trend with increasing shrub age. The stoichiometric ratios C:N, C:P and N:P in the leaves, roots and soil showed an upward trend, and the N:P ratios in the leaves and roots were similar. (2) Among the stoichiometric characteristics of the leaves, C, N and P, leaves P and C:P are the most sensitive to shrub age changes, and have ecological implications for the growth and population dynamics of A. mongolicus. The average N:P ratios of young A. mongolicus leaves in young, middle-aged and mature shrubs were 15.32, 18.23 and 21.76, respectively. It can be seen that with an increase in shrub age, the growth of A. mongolicus gradually shifted from being jointly restricted by N and P to being more restricted by P. (3) The N content and the C∶N and N∶P ratios of A. mongolicus are classified as “strictly homoeostasis “, which shows strong plant homoeostasis for environmental adaptability. The N supplemented by symbiotic nitrogen fixation makes A. mongolicus have strong N internal homoeostasis. Therefore, in a desert grassland with low N content, the growth process of A. mongolicus may be easily restricted by P due to the additional N absorbed by it. (4) The C, N and P contents of the leaves, roots and soils of the three shrubs were shown as leaf > root > soil, and the difference was significant (p < 0.05). The correlation analysis showed that the C, N and P contents of the soil, roots and leaves and their stoichiometric ratio characteristics of the three shrubs showed a certain correlation. Among them, the P content of the soil was significantly related to the N:P ratio of the leaves and roots. Therefore, P is likely to become a limiting factor in the plant growth and repair process of the plant ecosystem in the A. mongolicus population. In summary, during the growth of A. mongolicus, special attention should be paid to the balance of nutrients. In order to improve its productivity, it is recommended to reasonably apply P fertilizers in the process of tending management to enhance the soil nutrient status and improve plant nutrient utilization efficiency and homoeostasis. Full article

The essence of plant ecological stoichiometry is to study the relationships between species and their environment, including nutrient absorption, utilization and cycling processes as well as the nutrient limitation of plants. Plants can regulate nutrient elements and adapt to environmental changes. To understand the adaptation mechanism, it is important to take plants as a whole and quantify the correlation between the chemometrics of different organs. Ammopiptanthus mongolicus is within the second-class group of rare–endangered plants in China and is the only evergreen broad-leaved shrub in desert areas. We analyzed the ecological stoichiometric characteristics of leaves, stems, roots, flowers and seeds of A. mongolicus in five habitats, namely fixed sandy land, semi-fixed sandy land, stony–sandy land, alluvial gravel slope and saline–alkali land. We found that (1) the nutrient contents of N, P and K were in the order of seed > flower > leaf > root > stem. The enrichment of the N, P and K in the reproductive organs promoted the transition from vegetative growth to reproductive growth. Additionally, (2) the contents of C, N, P and K and their stoichiometric ratios in different organs varied among different habitat types. The storage capacity of C, N and P was higher in sandy soil (fixed and semi-fixed sandy land), whereas the content of K was higher in gravelly soil (stony–sandy land and alluvial gravel slope), and the C:N, C:P and N:P were significantly higher in gravelly soil than those in sandy soil. A. mongolicus had higher nutrient use efficiency in stony–sandy land and alluvial gravel slope. Furthermore, (3) the C:N and N:P ratios in each organ were relatively stable among different habitats, whereas the K:P ratio varied greatly. The N:P ratios of leaves were all greater than 16 in different habitats, indicating that the growth was mainly limited by P. Moreover, (4) except for the P element, the content of each element and its stoichiometric ratio were affected by the interaction between organs and habitat. Habitat had a greater impact on C content, whereas organs had a greater influence on N, P and K content and C:N, C:P, C:K and N:P. Full article

Satellite-borne multispectral data are suitable for regional-scale grassland community classification owing to comprehensive coverage. However, the spectral similarity of different communities makes it challenging to distinguish them based on a single multispectral data. To address this issue, we proposed a support vector machine (SVM)–based method integrating multispectral data, two-band enhanced vegetation index (EVI2) time-series, and phenological features extracted from Chinese GaoFen (GF)-1/6 satellite with (16 $\mathrm{m}$) spatial and (2 d) temporal resolution. To obtain cloud-free images, the Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model (ESTARFM) algorithm was employed in this study. By using the algorithm on the coarse cloudless images at the same or similar time as the fine images with cloud cover, the cloudless fine images were obtained, and the cloudless EVI2 time-series and phenological features were generated. The developed method was applied to identify grassland communities in Ordos, China. The results show that the Caragana pumila Pojark, Caragana davazamcii Sanchir and Salix schwerinii E. L. Wolf grassland, the Potaninia mongolica Maxim, Ammopiptanthus mongolicus S. H. Cheng and Tetraena mongolica Maxim grassland, the Caryopteris mongholica Bunge and Artemisia ordosica Krasch grassland, the Calligonum mongolicum Turcz grassland, and the Stipa breviflora Griseb and Stipa bungeana Trin grassland are distinguished with an overall accuracy of 87.25%. The results highlight that, compared to multispectral data only, the addition of EVI2 time-series and phenological features improves the classification accuracy by 9.63% and 14.7%, respectively, and even by 27.36% when these two features are combined together, and indicate the advantage of the fine images in this study, compared to 500 $\mathrm{m}$ moderate-resolution imaging spectroradiometer (MODIS) data, which are commonly used for grassland classification at regional scale, while using 16 $\mathrm{m}$ GF data suggests a 23.96% increase in classification accuracy with the same extracted features. This study indicates that the proposed method is suitable for regional-scale grassland community classification. Full article