Wu Xinhong, Li Shihui, Deng Yan, Duan Zhenchun, Li Yiran, Jiang Luhua, Liu Xueduan, Fu Shaodong, Liang Yili
School of Resource Processing and Bioengineering, Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China.
Hunan Institute of Microbiology, Hunan Academy of Agricultural Sciences, Changsha, 410125, China.
BMC Plant Biol. 2025 Sep 24;25(1):1214. doi: 10.1186/s12870-025-07168-4.
Paris polyphylla (P. polyphylla), a medicinal herb valued in traditional Chinese medicine, struggles with slow growth rate and long maturation periods, hindering sustainable cultivation and commercial production-especially for polyphyllins, its key bioactive compounds. Although plant growth-promoting rhizobacteria (PGPR) have shown potential in enhancing crop productivity and secondary metabolite accumulation, their application in slow-growing medicinal plants like P. polyphylla remains underexplored. RESULTS: In this study, 25 strains with inorganic phosphorus-dissolving, potassium-solubilizing and nitrogen-fixing abilities were isolated from the rhizosphere soil of P. polyphylla, mainly belonging to Bacillus, Pseudomonas, and Rhizobium. Among them, the strain Pseudomonas palleroniana P6 exhibited the best growth-promoting effect on grass. The whole genome analysis demonstrated that P. palleroniana P6 could promote forage growth by secreting phosphatases, organic acids, and producing substances like IAA and siderophore. Field experiments were carried out to further validate the impact of P. palleroniana P6 on the growth of P. polyphylla. The results revealed that P. palleroniana P6 remarkably enhanced the biomass of P. polyphylla root and the content of polyphyllin I, II, and VII, and significantly increased the soil available potassium content. The transcriptome results indicated that the application of P. palleroniana P6 considerably increased the expression of genes related to the plant hormone signal transduction pathway involved in growth regulation, cholesterol synthesis, terpenoid backbone synthesis and the energy metabolism pathway associated with polyphyllins synthesis in P. polyphylla. CONCLUSIONS: This study systematically investigated the growth-promoting effects and secondary metabolic regulation mechanisms of the bacterial inoculant P. palleroniana P6 on the endangered medicinal plant P. polyphylla. The findings highlight the potential of P. palleroniana P6 in promoting plant growth and enhancing polyphenol accumulation in P. polyphylla, providing valuable insights for the application of microbial inoculants in enhancing the growth and bioactive compound production of perennial medicinal plants.
重楼是一种在传统中药中备受珍视的药用植物，但生长速度缓慢且成熟期长，这阻碍了其可持续种植和商业化生产，尤其是其关键生物活性成分重楼皂苷的生产。尽管植物促生根际细菌（PGPR）已显示出提高作物生产力和促进次生代谢产物积累的潜力，但其在像重楼这样生长缓慢的药用植物中的应用仍未得到充分探索。结果：在本研究中，从重楼根际土壤中分离出25株具有解无机磷、解钾和固氮能力的菌株，主要属于芽孢杆菌属、假单胞菌属和根瘤菌属。其中，菌株苍白假单胞菌P6对牧草表现出最佳的促生长效果。全基因组分析表明，苍白假单胞菌P6可通过分泌磷酸酶、有机酸以及产生吲哚-3-乙酸（IAA）和铁载体等物质来促进牧草生长。进行了田间试验以进一步验证苍白假单胞菌P6对重楼生长的影响。结果表明，苍白假单胞菌P6显著提高了重楼根的生物量以及重楼皂苷I、II和VII的含量，并显著增加了土壤有效钾含量。转录组结果表明，施用苍白假单胞菌P6显著增加了重楼中与参与生长调节的植物激素信号转导途径、胆固醇合成、萜类骨架合成以及与重楼皂苷合成相关的能量代谢途径相关基因的表达。结论：本研究系统地研究了接种剂苍白假单胞菌P6对濒危药用植物重楼的促生长作用和次生代谢调控机制。研究结果突出了苍白假单胞菌P6在促进重楼植物生长和提高多酚积累方面的潜力，为微生物接种剂在促进多年生药用植物生长和生物活性化合物生产中的应用提供了有价值的见解。
