Global climate change has become a major threat to biodiversity, posing severe challenges to species conservation. This is particularly true for species such as Horsfieldia tetratepala that have extremely small populations in the wild. Little is known about the species distribution of H. tetratepala in the current climate, as well as how that will change with potential future climates. The key environmental factors that influence its expansion, especially its habitat sustainability and its potential to adapt to climate change, are also unknown, though such information is vital for the protection of this endangered species. Based on six climate factors and 25 species distribution points, this study used the maximum entropy model (MaxEnt) to simulate the potential distribution for H. tetratepala in three periods (current, 2050s, and 2070s), and to investigate the changes in distribution patterns and the main environmental factors affecting species distribution. The modeling results show that the most important bioclimatic variables affecting H. tetratepala were precipitation of the warmest quarter (Bio_18) and temperature seasonality (Bio_4). The suitable areas for H. tetratepala will gradually be lost in Yunnan but will be generally offset in the northeastward direction, expanding in Hainan, Guangzhou, and Taiwan provinces under the future climate conditions. Therefore, we recommend protecting the habitats of H. tetratepala in Yunnan and strengthening the in-depth species investigation and monitoring in areas (Hainan, Guangzhou, and Taiwan) where no related reports of H. tetratepala have been reported. The results improve our understanding of this species’ response under the changing climate and benefit strategies for its conservation.

Soil microbes play an important role in plant invasion, and parasitic plants regulate the growth of invasive plants. However, the mechanisms by which parasitic plants regulate the effects of soil microbes on invasive plants have not been investigated. Here, we used the invasive plant Alternanthera philoxeroides and the holoparasitic plant Cuscuta grovonii to test whether and how C. grovonii parasitism shifts the effect of native soil microbes on the growth of A. philoxeroides. In a factorial setup, A. philoxeroides was grown in pots with the presence versus absence of parasitism and the presence versus absence of native soil microbes. The findings showed that native soil microbes increased the biomass and clonal growth of A. philoxeroides only in the absence of a parasite, whereas parasitism decreased the biomass and clonal growth of A. philoxeroides only in the presence of soil microbes. In addition, the presence of soil microbes increased the deleterious effects of the parasite on A. philoxeroides. These results indicate that parasitism can shift the effects of native soil microbes on the growth of the invasive plant A. philoxeroides. Our results enrich the understanding of the mechanisms underlying the success of plant invasion.

Introduction: Soil salinization threatens global land use and food security, and halophytes combined with peat amendments are promising for saline-alkali soil remediation. Methods: Here, we integrated transcriptomic and physiological analyses to investigate the adaptive responses of Suaeda glauca and S. salsa grown in saline-alkaline soils amended with peat at 0, 6, or 18 g/kg. Results and discussion: Our results showed that a high peat concentration (18 g/kg) significantly improved salt tolerance and biomass accumulation in both species through distinct species-specific strategies. S. glauca upregulated growth-related pathways (e.g., nitrogen metabolism, and tricarboxylic acid cycle) mediated by bHLH and bZIP transcription factors (TFs), whereas S. salsa activated stress-mitigating secondary metabolism (e.g., flavonoids, phenylpropanoids, anthocyanins) regulated by MYB and NAC TFs. A conserved response across both species was the downregulation of genes involved in amino acid degradation, which helps conserve nitrogen for osmoprotection. RT-qPCR analysis confirmed the reliability of the RNA-seq data. This study identified 18 g/kg as the optimal peat concentration, uncovers species-specific adaptive mechanisms in halophytes, and lays a foundation for the precisely selection of halophyte-peat combinations in saline-alkaline soil remediation.