USP21 is a kind of deubiquitinating enzymes involved in the malignant progression of various cancers, while its role in gastric cancer (GC) and the specific molecular mechanism are still unclear. This study probed into the function of USP21 in vitro and in vivo, and discussed the regulatory mechanism of USP21 in GC in vitro. We reported that USP21 promoted GC cell proliferation, migration, invasion, and stemness in vitro, and regulated GC tumor growth and cell stemness in mice in vivo. USP21 stabilized the expression of GATA3 by binding to GATA3. Besides, GATA3 also regulated the expression of MAPK1 at the transcriptional level. A series of in vitro experiments testified that USP21 regulated the expression of MAPK1 by binding to transcription factor GATA3, thereby regulating the tumor growth and cell stemness of GC. Overall, this study identified a new USP21/GATA3/MAPK1 axis, which plays a pivotal role in promoting the malignant progression of GC and might provide a potential target for treatment.

White pines (Pinus subsect. Strobus) play important roles in forest ecosystems in the Northern Hemisphere. Species of this group are narrowly distributed or endangered in China. In this study, we used a species distribution model (SDM) to project and predict the distribution patterns of the 12 species of Chinese white pine under a variety of paleoclimatic and future climate change scenarios based on 39 high-resolution environmental variables and 1459 distribution records. We also computed the centroid shift, range expansion/contraction, and suitability change of the current distribution area to assess the potential risk to each species in the future. The modeling results revealed that the suitable habitat of each species is consistent with but slightly larger than its actual distribution range and that temperature, precipitation, and UV radiation are important determining factors for the distribution of different white pine species. The results indicate that the Last Glacial Maximum (LGM) greatly affected the current distribution of the Chinese white pine species. Additionally, it was predicted that under the future climate change scenarios, there will be a reduction in the area of habitats suitable for P. armandii, P. morrisonicola, and P. mastersiana. Furthermore, some of the current distribution sites of P. armandii, P. kwangtungensis, P. mastersiana, P. morrisonicola, P. sibirica, and P. wallichiana were predicted to become more unsuitable under these scenarios. These results indicate that some Chinese white pine species, such as P. armandii, P. morrisonicola, and P. mastersiana, may have a very high risk of population shrinkage in the future. Overall, this study provided relevant data for the long-term conservation (both in situ and ex situ) and sustainable management of Chinese white pine species.

Background: Invasive plants pose a major threat to global biodiversity, yet the molecular and genomic mechanisms underlying their success remain poorly understood. Here, we investigate the invasion of the common reed Phragmites australis , a grass species that became invasive in North America after its introduction from Europe, to elucidate the molecular mechanisms potentially underlying its invasion process. Results: By integrating single-cell RNA sequencing, spatial transcriptomics, and comparative genomics, we construct a single-cell atlas of Phragmites australis , and identify 19 transcriptionally distinct cell types, including meristematic cells, parenchyma, mesophyll, epidermal, and vascular tissues. Comparative analysis of common garden-grown native populations from Europe and invasive populations from North America reveals a significant proportion of differentially expressed genes located on B chromosomes, which show copy number expansion in invasive genomes. Four B-chromosome genes, PaChr24B.43 ( IMP-α3 ), PaChr24B.82 ( GATA2 ), PaChr24B.218 ( SCC3 ), and PaChr24B.240 ( SCC3 ), are consistently differentially expressed between invasive and noninvasive populations across nearly all cell types. At the tissue level, mesophyll, parenchyma, vascular, and epidermal cells in the invasive population all exhibit increased gene expression in response to sugar starvation and light deprivation. Epidermal cells also show strong activated gene expression in response to hypoxia but suppressed expression of genes involved in the defence related respiratory burst. Conclusions: This study establishes a cell type-resolved molecular atlas of a nonmodel invasive plant and reveals cell type-specific gene regulatory mechanisms within the regenerative shoot system. These findings advance our understanding of the cellular and genomic basis of plant invasiveness and provide a foundation for future ecological research and management.

Urban wildlife conservation is emerging as a critical component of sustainable city ecosystems. Rather than simply increasing tree abundance or species richness, conservation management should focus on key species. In this research, Xishan Forest Park in Beijing was chosen as a case study. Our aim was to identify keystone taxa critical for avian foraging and nesting during the breeding season. We performed a network analysis linking bird species, their diets, and nest plants. Dietary components were detected using DNA metabarcoding conducted with avian fecal samples. Nest plants were identified via transect surveys. Two indices of the network, degree and weighted mean degree, were calculated to evaluate the importance of the dietary and nest plant species. We identified 13 bird host species from 107 fecal samples and 14 bird species from 107 nest observations. Based on the degree indices, fruit trees Morus and Prunus were detected as key food sources, exhibiting both the highest degree (degree = 9, 9) and weighted mean degree (lnwMD = 5.21, 4.63). Robinia pseudoacacia provided predominant nesting sites, with a predominant degree of 7. A few taxa, such as Styphnolobium japonicum and Rhamnus parvifolia, served dual ecological significance as both essential food sources and nesting substrates. Scrublands, as a unique habitat type, provided nesting sites and food for small-bodied birds. Therefore, targeted management interventions are recommended to sustain or enhance these keystone resource species and to maintain the multi-layered vertical vegetation structure to preserve the diverse habitats of birds.

Salinization and eutrophication are increasingly severe pollution problems in wetlands. Myriophyllum spicatum is a cosmopolitan species widely used for pollution control, but its physiological responses under combined stressors remain largely unknown. Here, we used mesocosms to investigate the ecophysiological responses of M. spicatum to three ammonia nitrogen concentrations (0, 1.5, and 3 mg L⁻¹) and two salt concentrations (0 and 5 g L⁻¹). Shoot and stem biomass were significantly affected by both salinity and nitrogen, whereas leaf phosphorus and stem nitrogen responded only to salinity (two-way ANOVA, p < 0.05). A significant salinity–nitrogen interaction was observed for stem biomass (p < 0.05); specifically, low nitrogen alone caused no significant reduction, but under saline conditions it markedly exacerbated biomass suppression. A significant salt–nitrogen interaction was detected for stem biomass (p < 0.05), such that low nitrogen alone did not significantly reduce stem biomass but exacerbated its suppression under saline conditions. These indicate potential synergistic environmental effects and suggest that even low nutrient inputs may aggravate stress under salt exposure. Stem biomass was significantly negatively correlated with malondialdehyde content (Pearson analysis, p < 0.05). Salt–nitrogen co-stress significantly increased malondialdehyde content (Tukey HSD test), indicating enhanced lipid peroxidation and associated oxidative damage, which may represent a physiological mechanism underlying growth inhibition in M. spicatum. Our findings demonstrate the complex adaptive responses of M. spicatum and emphasize the need to consider salt–nutrient interactions in conservation and restoration practices.