Lycoris radiata is the major source of Amaryllidaceae alkaloids, having various medicinal activities. However, the low content of these alkaloids in planta limits their pharmaceutical development and utilization. In this study, the ability of bacterial endophytes to enhance the accumulation of five important Amaryllidaceae alkaloids was investigated. A total of 188 bacterial endophytes were isolated from L. radiata and their composition and diversity were analyzed. Fourteen ones were demonstrated to significantly increase the concentration of the alkaloids of interest in different organs, up to 11.1-fold over the control level, with no adverse influence on the plant growth. An additional 3 bacterial endophytes were found to significantly increase the dry weight of L. radiata with no adverse influence on the concentration of the alkaloids in planta, so the total yield of alkaloids in planta was increased up to 2.4-fold over the control level. Considering the plant growth-promoting abilities of these bacterial endophytes, it is speculated that the indole-3-acetic acid and siderophore secreted by them, combined with their nitrogen fixation ability, may contribute to the enhanced plant growth and the increased alkaloid accumulation in L. radiata. To our knowledge, this work is firstly defining the diversity of culturable bacterial endophytes in L. radiata and determining which species promoted the accumulation of Amaryllidaceae alkaloids. It provides several valuable bacterial inoculants that can be further applied to improve alkaloid production in L. radiata and broadens our understanding of the interactions between a medicinal plant and the bacterial endophytes.

辐射石蒜是石蒜科生物碱的主要来源，具有多种药用活性。但是，植物中这些生物碱的含量低，限制了它们的药物开发和利用。在这项研究中，研究了细菌内生菌增强五种重要金莲花科生物碱积累的能力。从辐射乳杆菌中共分离出188个细菌内生菌，并对其组成和多样性进行了分析。已证明有14种显着增加了不同器官中目标生物碱的浓度，比对照水平高出11.1倍，并且对植物生长没有不利影响。发现另外3种细菌内生菌能显着增加细菌的干重。石蒜与生物碱的浓度没有不良影响的在植物中，因此生物碱的总收率在植物中相对于对照水平增加至2.4倍。考虑到这些细菌内生菌对植物的生长促进能力，推测它们分泌的吲哚-3-乙酸和铁载体与它们的固氮能力结合，可能有助于植物生长的增强和L中生物碱积累的增加。辐射 据我们所知，这项工作首先确定了辐射乳杆菌中可培养细菌内生菌的多样性。并确定哪些物种促进了金莲花科生物碱的积累。它提供了几种有价值的细菌接种剂，可进一步应用于改善辐射乳杆菌中生物碱的生产，并拓宽了我们对药用植物与细菌内生菌之间相互作用的理解。