Background: Pseudostellaria heterophylla is used in traditional Chinese medicine, so ensuring an adequate supply of plant material with high levels of bioactive components is important.Methods: Using an optimized maximum entropy niche model and assays of bioactive components from cultivation samples, this study started from the plant’s natural distribution area and estimated correlations of ecological factors with not only abundance of the plant but also abundance of polysaccharides and heterophyllin B. These correlations were combined with the spatial analysis function in ArcGIS to generate maps of the suitability of different habitats in China for cultivating P. heterophylla under current climate conditions and different models of climate change.Results: The following ecological factors emerged as particularly important for habitat suitability: precipitation of driest month and driest quarter, annual precipitation, annual mean temperature, temperature seasonality, and mean temperature of coldest quarter, contributing to a cumulative total of 87%. Under current climate conditions, optimum habitats of P. heterophylla were mainly distributed in the southwestern region (Guizhou) and eastern regions (Anhui, Zhejiang, Fujian, Jiangsu) of China, and only 0.197×10⁶ km² of these areas were optimum habitat. In future climate change scenarios, the optimal habitat area of P. heterophylla exhibited an increase across different time periods under the SSP5-8.5 climate scenario. By the 2090s, distribution area of high heterophyllin B content under SSP5-8.5 climate scenarios will increase significantly, distribution area of high polysaccharide content had little change under all three climate scenarios (SSP 1-2.6, 2-4.5, 5-8.5). The center of mass of suitable habitat migrates southwestward under scenario SSP 1-2.6 and SSP 2-4.5, while it migrates northward under scenario SSP 5-8.5. Under the three climate scenarios, the center of mass of suitable habitat migrated consistently with that of high polysaccharide content but differed from that of high heterophyllin B content.Conclusion: These findings provide a crucial foundation for cultivating P. heterophylla with superior medicinal properties, developing adaptive management strategies to enhance conservation efforts, and ensuring sustainable utilization in the face of global climate change.

Borneol is a precious monoterpenoid with two chiral structures, (-)-borneol and (+)-borneol. Bornyl diphosphate synthase is the key enzyme in the borneol biosynthesis pathway. Many (+)-bornyl diphosphate synthases have been reported, but no (-)-bornyl diphosphate synthases have been identified. Blumea balsamifera leaves are rich in borneol, almost all of which is (-)-borneol. In this study, we identified a high-efficiency (-)-bornyl diphosphate synthase (BbTPS3) from B. balsamifera that converts geranyl diphosphate (GPP) to (-)-bornyl diphosphate, which is then converted to (-)-borneol after dephosphorylation in vitro. BbTPS3 exhibited a K_m value of 4.93 ± 1.38 μM for GPP, and the corresponding k_cat value was 1.49 s⁻¹. Multiple strategies were applied to obtain a high-yielding (-)-borneol producing yeast strain. A codon-optimized BbTPS3 protein was introduced into the GPP high-yield strain MD, and the resulting MD-B1 strain produced 1.24 mg·L^-1 (-)-borneol. After truncating the N-terminus of BbTPS3 and adding a Kozak sequence, the (-)-borneol yield was further improved by 4-fold to 4.87 mg·L^-1. Moreover, the (-)-borneol yield was improved by expressing the fusion protein module of ERG20^F96W-N127W-YRSQI-t14-BbTPS3K2, resulting in a final yield of 12.68 mg·L^-1 in shake flasks and 148.59 mg·L^-1 in a 5-L bioreactor. This work is the first reported attempt to produce (-)-borneol by microbial fermentation.

Enhancing stress resilience constitutes a pivotal strategy in mitigating the risk of depression, making it a critical component of both prevention and treatment. In the current work, we identified a compound, gastrodin (GAS), as capable of enhancing stress resilience, as demonstrated by its ability to protect against depression following chronic stress exposure. To elucidate the potential of GAS to promote neurogenesis under chronic stress, along with the associated cellular and molecular processes involved. We evaluated the effect of GAS on NSPC proliferation and differentiation using both in vitro and in vivo investigations. Neurogenesis was inhibited using temozolomide to verify GAS's impact on stress resilience. Comprehensive methodologies, including hippocampal transcriptome analysis and western blotting, were utilized to identify the involvement of the Wnt/β-catenin pathway. Immunolocalization was conducted to confirm β-catenin's nuclear translocation in SOX2⁺ cells within the hippocampal dentate gyrus subgranular zone. GAS demonstrated robust stimulation of NSPC proliferation and neuronal differentiation, enhancing adult hippocampal neurogenesis under conditions of chronic stress. Inhibition of neurogenesis negated GAS's protective effects on stress resilience. Integrated analysis pointed to the Wnt/β-catenin signaling pathway within NSPCs as a crucial mechanism facilitating GAS-promoted neurogenesis. Inhibiting Wnt expression or blocking β-catenin's nuclear translocation abolished GAS's neurogenic and stress-resilience enhancing effects. These results suggested that GAS directly activates the Wnt/β-catenin signaling pathway, which promotes the proliferation and neuronal differentiation of NSPCs, thereby enhancing adult hippocampal neurogenesis and promoting stress resilience to mitigate the risk of depression.

Pinelliae rhizoma is the dried tuber of Pinellia ternata (Thunb.) Breit., and has been used for thousand of years in traditional Chinese medicine as an antivomit, anticough, and analgesic (Ying et al. 2007). In September 2022, P. ternata planted in Bijie, Guizhou Province, showed severe soft rot symptoms with incidence of about 50%. The diseased plants showed water-soaked symptoms and produced a foul soft rot smell, and finally the whole plant collapsed. Lesions were first observed at the tip of a leaf or wound, and symptoms of the disease spread rapidly, with the entire plant collapsing and dying within a week. The tissue sections of six plants with typical symptoms from the diseased field were disinfected with 75% ethanol for 30 seconds and 0.3% NaClO for 3 minutes. The tissue sections were then washed with sterile water for three times. A small piece of tissue (5x5mm) was removed from the edge of the lesion and mashed in a 1.5 ml centrifuge tube containing 20 μl of sterile water. The tissue liquid was then diluted 100 times with prepared sterile water. The bacteria were streaked on LB (tryptone/yeast extract/NaCl) AGAR medium and cultured at 37°C for 48 h (Kravitz, 1962). Isolated colonies were streaked on Luria-Bertani (LB) AGAR medium to obtain single colonies for further identification. A total of 13 representative isolates were selected for PCR amplification using primers targeting the conserved region of the 16S rDNA gene, which were in turn analyzed via the BLASTn search engine on the NCBI website. The results of the analysis revealed that seven of the isolates were similar to P. aroidearum strain SCRI 109 (GenBank accession no. NR_159926), with strain BX13 exhibiting the highest similarity to P. aroidearum (99.93% similarity), and therefore, this strain was selected for further investigation. The strain BX13 was incubated on LB solid medium for 24 h at 37 °C, and the single colonies were creamy white, translucent and round, slightly elevated in the center, with smooth surfaces and neat edges (Figure S1 B1). Then,the Scanning Electron Microscope revealed that the thalli of strain BX13 were short rod-shaped and somewhat blunt round at both ends (Figure S1 B2). The steward genes (icdA, gapA, proA) of BX13 were amplified and sequenced for further identification. The sequences of the amplified fragments were all deposited in GenBank 16S rDNA (OQ874505,) icdA (OQ954122)，gapA (OQ954123), proA (OQ954124). Sequence analysis using the BLASTn program at the NCBI revealed gene icdA, gapA, and proA had 100% identity to P. aroidearum strain QJ002 (GenBank accession no. CP090597).. Meanwhile, a maximum likelihood phylogenetic tree was constructed based on multigene sequence analysis of BX13 16S rDNA and steward genes (gapA, icdA, proA) by MEGA X (Liang et al. 2022). Phylogenetic results also showed that BX13 and P. aroidearum strain QJ002 gathered in the same clade(Figure S2). Accordingly, the morphological and molecular characteristics of strain BX13 indicate that it is P. aroidearum. (Nabhan S., et al.2013,Xu et al. 2020). In order to confirm the pathogenicity of strain BX13, a bacterial suspension containing 107 CFU/ml (10 ml/ inoculation point) was injected into the base of a one-week-old P. ternata stems, control seedlings were inoculated with sterile water, inoculated and control seedlings (each of six plants) were kept in a growth chamber maintained at 26°C with a relative humidity range of 70% to 80%. Plants were watered as needed. After 3 days, the stem base of the plants inoculated with bacteria solution showed water-soaked necrosis and stems began to rot, while the plants inoculated with water did not show this symptom. The strains were then successfully re-isolated from the symptomatic P. ternata. Then the strain re-isolated was identified using the BLASTn program at the NCBI and found that it has the same 16S rDNA, icdA, gapA, and proA sequences as strain BX13, thus completing the Koch's postulates. To our knowledge, this is the first report of P. aroidearum causing P. ternata soft rot in China, which expands its known host range. Accordingly, this study provides essential information for the breeding of P. ternata resistant to bacterial soft rot and the development of control measures in China.