Liu Tianrui, Hua Zhongyi, Han Pengjie, Zhao Yuyang, Zhou Junhui, Jin Yan, Li Xiaolin, Huang Luqi, Yuan Yuan
State Key Laboratory of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China.
School of Pharmaceutical Sciences, Peking University, Beijing, China.
Front Microbiol. 2022 Mar 17;13:842893. doi: 10.3389/fmicb.2022.842893. eCollection 2022.
is an entirely heterotrophic plant, the growth of which is completely reliant on , an orchid mycorrhizal fungus. To avoid damaging ecosystems, cultivation is shifting from woodland to farmland. However, whether the microbial community structure remains stable during this conversation is unknown. Here, we cultivated in woodland or farmland and found that woodland-cultivated produced a greater yield and larger tuber size. The relative abundance of was 22.84- and 122.25-fold higher in woodland- and farmland-cultivated soil samples, respectively, than that in uncultivated soil samples. To investigate how impacts the growth of and establishes symbiosis with , three spp. strains (HPDA25, SBD3, and SBD11) were isolated from mycorrhizosphere soil samples. It was found that these strains, especially HPDA25, promoted the growth of . Ultra-performance liquid chromatography coupled to a triple quadrupole mass spectrometry analysis detected the indole-3-acetic acid with 16.24 ng/ml in HPDA25 fermentation solution. Co-culturing with the strain HPDA25 or exogenous indole-3-acetic acid increased the branching and fresh weight of rhizomorphs and the growth rate and extracellular laccase activity of , compared with cultured alone. The results of RNA-seq and quantitative real-time polymerase chain reaction analysis showed that co-culturing with HPDA25 increased the expression level of the genes including hydrophobin, SUR7/PalI family, and pectin methylesterase, whereas decreased the expression levels of glycolysis-related genes. Furthermore, co-culturing with the strain HPDA25, promotes the growth of and enhances the tuber size of . These results provide new insights into an orchid mycorrhizal symbiosis and the cultivation of .
是一种完全异养的植物，其生长完全依赖于一种兰花菌根真菌。为避免破坏生态系统，其种植正从林地转向农田。然而，在此转变过程中微生物群落结构是否保持稳定尚不清楚。在这里，我们在林地或农田中种植，发现林地种植的产量更高，块茎更大。林地和农田种植土壤样本中该菌的相对丰度分别比未种植土壤样本高22.84倍和122.25倍。为研究该菌如何影响的生长并与之建立共生关系，从菌根际土壤样本中分离出三株该菌菌株（HPDA25、SBD3和SBD11）。发现这些菌株，尤其是HPDA25，促进了的生长。超高效液相色谱-三重四极杆质谱分析在HPDA25发酵液中检测到16.24 ng/ml的吲哚-3-乙酸。与菌株HPDA25或外源吲哚-3-乙酸共培养，与单独培养相比，增加了根状菌索的分支和鲜重以及的生长速率和细胞外漆酶活性。RNA测序和定量实时聚合酶链反应分析结果表明，与HPDA25共培养增加了包括疏水蛋白、SUR7/PalI家族和果胶甲酯酶等基因的表达水平，而降低了糖酵解相关基因的表达水平。此外，与菌株HPDA25共培养，促进了的生长并增大了的块茎大小。这些结果为兰花菌根共生和的种植提供了新的见解。
