Hairgrass (Deschampsia caespitosa), a widely distributed grass species considered promising in the ecological restoration of degraded grassland in the Qinghai-Xizang Plateau, is likely to be subjected to frequent drought and waterlogging stress due to ongoing climate change, further aggravating the degradation of grassland in this region. However, whether it would acclimate to water stresses resulting from extreme climates remains unknown. Proline accumulation is a crucial metabolic response of plants to challenging environmental conditions. This study aims to investigate the changes in proline accumulation and key enzymes in hairgrass shoot and root tissues in response to distinct climate extremes including moderate drought, moderate waterlogging, and dry–wet variations over 28 days using a completely randomized block design. The proline accumulation, contribution of the glutamate and ornithine pathways, and key enzyme activities related to proline metabolism in shoot and root tissues were examined. The results showed that water stress led to proline accumulation in both shoot and root tissues of hairgrass, highlighting the importance of this osmoprotectant in mitigating the effects of environmental challenges. The differential accumulation of proline in shoots compared to roots suggests a strategic allocation of resources by the plant to cope with osmotic stress. Enzymatic activities related to proline metabolism, such as Δ¹-pyrroline-5-carboxylate synthetase, ornithine aminotransferase, Δ¹-pyrroline-5-carboxylate reductase, Δ¹-pyrroline-5-carboxylate dehydrogenase, and proline dehydrogenase, further emphasize the dynamic regulation of proline levels in hairgrass under water stress conditions. These findings support the potential for enhancing the stress resistance of hairgrass through the genetic manipulation of proline biosynthesis and catabolism pathways.

Incarvillea compacta Maxim is a traditional Tibetan medicine used to treat inflammation-related diseases, such as pneumonia, fever, jaundice, and otitis media. However, no studies have examined its anti-inflammatory mechanism. To validate the anti-inflammatory activity of I. compacta extract (ICE) and its protective effect on acute alcoholic gastritis, Phytochemicals of I. compacta were identified using Ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). Lipopolysaccharide (LPS)-induced RAW 264.7 macrophages were used in vitro along with an in vivo a mouse acute gastritis model. Pro-inflammatory mediators and cytokines were measured using the Griess reagent and Cytometric bead array (CBA) assay. Furthermore, inflammation-related molecules were analysed by Western blotting, RNA-Seq, and real-time quantitative PCR (RT-qPCR). The experimental results revealed that ICE decreased the nitric oxide (NO), IL-6, MCP-1, and TNF-α levels in LPS-stimulated RAW 264.7 cells, and downregulated the expression and phosphorylation of PDK1, AKT, and GSK3β. Moreover, ICE also downregulated the activation of NLRP3. The RNA-Seq analysis revealed that 340 differentially expressed genes (DEGs) response to ICE treatment was enriched in several inflammation-related biological processes. The results of the in vivo mouse acute gastritis model showed that ICE significantly reduced inflammatory lesions in the gastric mucosa and remarkably downregulated the expression of iNOS, TNF-α, IL-1β, and IL-6 mRNA in gastric tissue. Therefore, the results of this study obtained scientific evidence supporting the use of I. compacta.

Biological soil crusts (BSCs) play key roles in arid, semi-arid regions and ecological marginal habitats. This study focused on four types of sand-fixing plantations established in 1990 in alpine sandy land (Salix psammophila, SL; Caragana korshinskii, NT; Salix cheilophila, WL; Populus simonii, XYY). Soil samples were collected from bare sand, algae crusts, and moss crusts. Soil particle size distribution, physicochemical properties, and enzyme activity were determined. Then bacterial communities were analyzed using high-throughput (Illumina) sequencing and the correlations among these three factors were examined. The results showed that: (1) From bare sand to algae and moss crusts, the content of fine particles (clay + silt) gradually increased. (2) Soil water content (SWC), nutrients and enzyme activities increased progressively. (3) In the study area, the dominant bacterial phyla of BSCs included Pseudomonadota, Cyanobacteria, Actinobacteriota and Vibrionota. Principal Coordinates Analysis (PCoA) and Analysis of Similarities (ANOSIM) results showed that BSCs drive the differentiation of bacterial communities during succession, while forest stands influence their spatial distribution. (4) Spearman’s correlation and redundancy analysis (RDA) showed that available phosphorus (AP), alkaline hydrolyzable nitrogen (AN), soil organic matter (SOM), catalase (CAT), pH, soil water content (SWC), and alkaline phosphatase (ALP) are key physicochemical factors shaping the bacterial community structure of BSCs. Mantel’s test confirmed that these variables mediated BSCs’ bacterial community structure. This study elucidates the mechanisms underlying ecological restoration via BSCs and provides a theoretical basis for future restoration efforts in alpine sandy land.