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.

Plant glutathione peroxidases (GPXs) are the main enzymes in the antioxidant defense system that sustain H₂O₂ homeostasis and normalize plant reaction to abiotic stress conditions. However, the genome-wide identification of the GPX gene family and its responses to environmental stresses, especially salt stress, in Nitraria sibirica, which is a shrub that can survive in saline environments, has not yet been reported. Here, we first report the genome-wide analysis of the GPX gene family in N. sibirica, leading to a total of seven NsGPX genes that are distributed on six of the twelve chromosomes. Phylogenetic analysis showed that NsGPX genes were grouped into four major groups (Group I-IV). Three types of cis-acting elements were identified in the NsGPX promoters, mainly related to hormones and stress response. The quantitative real-time PCR (qRT-PCR) analysis indicated that NsGPX1 and NsGPX3 were significantly up-regulated in stem and leaf, while NsGPX7 transcriptionally in root in response to salt stress. The current study identified a total seven NsGPX genes in N. sibirica via genome-wide analysis, and discovered that NsGPXs may play an important role in response to salt stress. Taken together, our findings provide a basis for further functional studies of NsGPX genes, especially in regarding to the resistance to salt stress of this halophyte plant N. sibirica, eventually aid in the discovery of new methods to restore overtly saline soil.

Calcineurin B-like (CBL) proteins are a class of important Ca²⁺ receptors that play key roles in plant stress response. CBLs have been shown to participate in responses to abiotic stresses such as drought, salt, and cold in many plant species, including Arabidopsis and rice. However, little is known about their potential functions in the desert halophyte Nitraria tangutorum. Here, we have identified 11 CBL genes distributed across six chromosomes of N. tangutorum and categorized them into four groups through phylogenetic analysis. Synteny analysis showed that they have strong collinear relationships and have undergone purifying selection during their evolution. NtCBL promoter regions contain a variety of cis-acting elements related to hormone and environmental stress responses. Real-time quantitative PCR showed that the expression of NtCBLs differed significantly among various tissues and was upregulated by salt and drought stress. We chose NtCBL1-1 for an in-depth functional characterization and observed that transgenic Arabidopsis plants expressing NtCBL1-1 exhibited increased tolerance to both drought and salt stress. Compared to wild-type Arabidopsis, transgenic lines showed higher germination rates, slower chlorophyll degradation, more soluble proteins, and reduced accumulation of the oxidative stress marker malondialdehyde. These findings indicate that NtCBL1-1 plays a significant role in responding to drought and salt stress, laying the foundation for further investigations into the functional mechanisms of NtCBL genes in N. tangutorum.

The calcineurin B-like-interacting protein kinase (CIPK) protein family plays a key role in the plant calcium ion-mediated signal transduction pathway, which regulates a plant’s response to abiotic stress. Nitraria sibirica pall. (N. sibirica) is a halophyte with a strong tolerance for high salt environments, yet how it is able to deal with salt stress on a molecular level is still unknown. Due to their function as described in other plant species, CIPK genes are prime candidates for a role in salt stress signaling in N. sibirica. In this study, we identified and analyzed the phylogenetic makeup and gene expression of the N. sibirica CIPK gene family. A total of 14 CIPKs were identified from the N. sibirica genome and were clustered into seven groups based on their phylogeny. The promoters of NsCIPK genes contained multiple elements involved in hormonal and stress response. Synteny analysis identified a total of three pairs of synteny relationships between NsCIPK genes. Each gene showed its own specific expression pattern across different tissues, with the overall expression of CIPK6 being the lowest, and that of CIPK20 being the highest. Almost all CIPK genes tended to respond to salt, drought, and cold stress, but with different sensitivity levels. In this study, we have provided a general description of the NsCIPK gene family and its expression, which will be of great significance for further understanding of the NsCIPK gene family function.

Ecological governance is essential to promoting the sustainable development of photovoltaic power stations in sandy regions and serves as a necessary measure for photovoltaic sand control. This study aims to investigate the impact of ecological governance measures on soil nutrients and plant growth, providing a theoretical foundation and scientific guidance for optimizing ecological management strategies in photovoltaic power stations located in sandy areas. The research focuses on two ecological governance measures: (1) the direct planting of Haloxylon ammodendron in bare sand in front of, between, and behind photovoltaic panels and (2) the planting of H. ammodendron after laying straw checkerboard barriers. The effects of these two measures on plant growth and soil nutrients were compared and analyzed across different positions relative to the photovoltaic panels (in front, between, and behind). The study revealed that the plant height of H. ammodendron was significantly higher than the control under both ecological governance measures in all three positions (p < 0.05). Furthermore, the crown width, aboveground biomass, underground biomass, and total biomass of H. ammodendron planted directly in bare sand as an ecological governance measure were significantly greater than those of plants grown after the installation of straw checkerboard barriers. A two-factor analysis of variance indicated that sampling location, ecological governance measures, and their interaction significantly affected the plant height and crown width of H. ammodendron (p < 0.01). Redundancy analysis demonstrated that soil available nitrogen was positively correlated with aboveground dry weight, underground dry weight, total biomass, and crown width, with all parameters increasing as soil available nitrogen content increased. Additionally, soil available nitrogen and soil available potassium were identified as key factors driving the growth of H. ammodendron. In conclusion, the ecological governance measures of planting H. ammodendron directly in bare sand within the photovoltaic park demonstrated superior growth and biomass outcomes compared with planting the species after the installation of straw checkerboard barriers.

Calcium-dependent protein kinases (CDPKs) are key Ca²⁺ sensors in plants, mediating responses to abiotic stresses via phosphorylation signaling. In the halophyte Nitraria sibirica, which thrives in saline soils, we identified 19 CDPK genes (NsCDPKs) and classified them into four canonical angiosperm clades, highlighting conserved functional modules. Promoter analysis revealed diverse cis-acting elements responsive to light, hormones (ABA, MeJA, auxin, GA, SA), and abiotic stresses (drought, cold, wounding), along with numerous MYB binding sites, suggesting complex transcriptional regulation. Transcriptome profiling under salt stress (100 and 400 mM NaCl) showed induction of most NsCDPKs, with several genes significantly upregulated in roots and stems, indicating coordinated whole-plant activation. These salt-responsive NsCDPKs were also upregulated by cold but repressed under PEG-simulated drought, indicating stress-specific regulatory patterns. Fifteen MYB transcription factors, differentially expressed under salt stress, were predicted to interact with NsCDPK promoters, implicating them as upstream regulators. This study identified a potential salt- and cold-responsive CDPK regulatory module and a MYB-mediated transcriptional hierarchy in N. sibirica, providing insights into the molecular mechanisms of salinity adaptation and highlighting candidate genes that could be explored for improving salt tolerance in crop species.