黄芪是一种著名的传统药用植物。然而,干旱和镉(Cd)污染是影响植物生长和产量的主要非生物胁迫因子,通过利用有益内生真菌提高宿主的抗逆性。为了评估深色间隔内生菌(DSE)对各种非生物胁迫的耐受性,10个DSE菌株[小孢子藻(Mc),Alternariaalstroemeriae(Aa),Lupini(Sl),新甲孢菌犯(Np),副甲衣原体(Pc),Macrophominaphaseolina(Mp\'),Papulasporaequi(Pe),赤链孢菌(AT),巨噬细胞假单胞菌(Mp),在本研究中,通过使用固体平板培养物和液体摇床培养物,在不同的干旱和Cd胁迫下研究了Paraphomaradicina(Pr)]。实验涉及使用不同浓度的PEG(0、9、18和27%)和Cd2(0、25、50和100mg/L)来模拟DSE上的不同胁迫条件。此外,研究了DSE(Np和At)在不同田间水容量(70%和40%)和不同CdCl2浓度(0、5、10和15mgCd/kg)下对A的生长的影响。结果表明,Aa的菌落生长速率,Np,PC,Mp\',和Mp在18%的PEG浓度下首先达到最大直径。Aa,Np,并且在100mgCd/L时保持生长活性。此外,Aa,Np,选择At进行干旱和Cd胁迫试验。干旱与Cd胁迫固体培养的结果表明,Np的生长速率显着优于其他菌株。在液体培养条件下,Np和Aa的生物量最高,在18%+25mgCd/L的浓度下,生物量为1.39g和1.23g,在18%+50mgCd/L浓度下,At的生物量最高为1.71g,分别。Np的CAT和POD活性在浓度为27%50mgCd/L和27%25mgCd/L时达到峰值水平,分别。与对照相比,这些水平显示增加了416.97%和573.12%,分别。Aa,Np,和At对SOD活性有积极影响。Aa的谷胱甘肽(GSH)含量,Np,在干旱和Cd的不同组合胁迫下,At增加。结构方程模型(SEM)分析表明,Aa对生物量有积极影响,对Cd含量有负面影响。而Np和At对Cd含量有正向影响。在40%田间水分容量和40%田间水分容量和5mgCd/kg土壤的协同胁迫下,Np和At显着增加了A的根重。本研究为农业种植体系的建立提供了指导,具有良好的开发利用价值。
Astragalus membranaceus is a famous traditional medicinal plant. However, drought and cadmium (Cd) pollution are the main abiotic stress factors that affect plant growth and yield and the ability to improve the host\'s stress resistance through the use of beneficial endophytic fungi. To evaluate the tolerance of dark septate endophytes (DSE) to various abiotic stresses, 10 DSE strains [Microsphaeropsis cytisi (Mc), Alternaria alstroemeriae (Aa), Stagonosporopsis lupini (Sl), Neocamarosporium phragmitis (Np), Paraphoma chlamydocopiosa (Pc), Macrophomina phaseolina (Mp\'), Papulaspora equi (Pe), Alternaria tellustris (At), Macrophomina pseudophaseolina (Mp), and Paraphoma radicina (Pr)] were investigated under different drought and Cd stressors in vitro by using solid-plate cultures and liquid-shaker cultures in the current study. The experiments involved using varying concentrations of PEG (0, 9, 18, and 27%) and Cd2+ (0, 25, 50, and 100 mg/L) to simulate different stress conditions on DSE. Additionally, the effect of DSE (Np and At) on the growth of A. membranaceus at different field water capacities (70% and 40%) and at different CdCl2 concentrations (0, 5, 10, and 15 mg Cd/kg) in soil was studied. The results demonstrated that the colony growth rates of Aa, Np, Pc, Mp\', and Mp were the first to reach the maximum diameter at a PEG concentration of 18%. Aa, Np, and At remained growth-active at 100 mg Cd/L. In addition, Aa, Np, and At were selected for drought and Cd stress tests. The results of the drought-combined-with-Cd-stress solid culture indicated that the growth rate of Np was significantly superior to that of the other strains. In the liquid culture condition, the biomasses of Np and Aa were the highest, with biomasses of 1.39 g and 1.23 g under the concentration of 18% + 25 mg Cd/L, and At had the highest biomass of 1.71 g at 18% + 50 mg Cd/L concentration, respectively. The CAT and POD activities of Np reached their peak levels at concentrations of 27% + 50 mg Cd/L and 27% + 25 mg Cd/L, respectively. Compared to the control, these levels indicated increases of 416.97% and 573.12%, respectively. Aa, Np, and At positively influenced SOD activity. The glutathione (GSH) contents of Aa, Np, and At were increased under different combined stressors of drought and Cd. The structural-equation-modeling (SEM) analysis revealed that Aa positively influenced biomass and negatively affected Cd content, while Np and At positively influenced Cd content. Under the stress of 40% field-water capacity and the synergistic stress of 40% field-water capacity and 5 mg Cd/kg soil, Np and At significantly increased root weight of A. membranaceus. This study provides guidance for the establishment of agricultural planting systems and has good development and utilization value.