Plant cell cultivations are being considered as an alternative to agricultural processes for producing valuable phytochemicals. Since many of these products (secondary metabolites) are obtained by direct extraction from plants grown in natural habitat, several factors can alter their yield. The use of plant cell cultures has overcome several inconveniences for the production of these secondary metabolites. Organized cultures, and especially root cultures, can make a significant contribution in the production of secondary metabolites. Most of the research efforts that use differentiated cultures instead of cell suspension cultures have focused on transformed (hairy) roots. Agrobacterium rhizogenes causes hairy root disease in plants. The neoplastic (cancerous) roots produced by A. rhizogenes infection are characterized by high growth rate, genetic stability and growth in hormone free media. These genetically transformed root cultures can produce levels of secondary metabolites comparable to that of intact plants. Hairy root cultures offer promise for high production and productivity of valuable secondary metabolites (used as pharmaceuticals, pigments and flavors) in many plants. The main constraint for commercial exploitation of hairy root cultivations is the development and scaling up of appropriate reactor vessels (bioreactors) that permit the growth of interconnected tissues normally unevenly distributed throughout the vessel. Emphasis has focused on designing appropriate bioreactors suitable to culture the delicate and sensitive plant hairy roots. Recent reactors used for mass production of hairy roots can roughly be divided as liquid-phase, gas-phase, or hybrid reactors. The present review highlights the nature, applications, perspectives and scale up of hairy root cultures for the production of valuable secondary metabolites.

中文翻译：

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毛状根培养，可大量生产高价值的次级代谢产物。

植物细胞培养被认为是替代农业生产有价值的植物化学物质的方法。由于这些产品（次生代谢产物）中的许多是通过直接从自然栖息地中生长的植物中提取而获得的，因此多种因素会改变其产量。植物细胞培养物的使用克服了产生这些次级代谢产物的一些不便之处。有组织的培养，尤其是根培养，可以在次生代谢产物的生产中做出重大贡献。大多数使用分化培养而不是细胞悬浮培养的研究工作都集中在转化的（毛）根上。发根农杆菌在植物中引起毛状根病。发根农杆菌感染产生的赘生性（癌性）根系具有高生长速率，遗传稳定性和无激素培养基的生长。这些基因转化的根系培养物可产生与完整植物相当的次级代谢产物。毛状根培养物为许多植物中有价值的次生代谢产物（用作药物，颜料和调味料）的高产量和高生产率提供了希望。商业开发毛状根栽培的主要限制因素是适当的反应器容器（生物反应器）的发展和规模扩大，使通常在整个容器中分布不均匀的相互连接的组织得以生长。重点是设计合适的生物反应器，以培养脆弱而敏感的植物毛状根。近期用于大规模生产毛根的反应器可大致分为液相，气相或混合反应器。