Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, The Jiangsu Provincial Platform for Conservation and Utilization of Agricultural Germplasm, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, Jiangsu, China.
Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, The Jiangsu Provincial Platform for Conservation and Utilization of Agricultural Germplasm, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, Jiangsu, China.
Microbiol Res. 2020 Oct;239:126501. doi: 10.1016/j.micres.2020.126501. Epub 2020 May 30.
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.
石蒜是石蒜科生物碱的主要来源，具有多种药用活性。然而，这些生物碱在植物体内的含量较低，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石蒜科生物碱积累的能力。从石蒜中分离出 188 种细菌内生菌，分析了它们的组成和多样性。其中 14 种被证明能显著提高不同器官中感兴趣的生物碱浓度，最高可达对照水平的 11.1 倍，而对植物生长没有不良影响。另外 3 种内生细菌被发现能显著增加石蒜的干重，而对植物体内生物碱的浓度没有不良影响，因此植物体内生物碱的总产量比对照水平提高了 2.4 倍。考虑到这些细菌内生菌的促生长能力，推测它们分泌的吲哚-3-乙酸和铁载体，以及它们的固氮能力，可能有助于增强植物的生长和增加石蒜中生物碱的积累。据我们所知，这项工作首次定义了可培养的石蒜内生细菌的多样性，并确定了哪些物种促进了石蒜科生物碱的积累。它提供了几种有价值的细菌接种剂，可进一步应用于提高石蒜中生物碱的产量，并拓宽了我们对药用植物与内生细菌相互作用的理解。
