This article describes the composition of root exudates, how these metabolites are released to the rhizosphere and their importance in the recruitment of beneficial microbiota that alleviate plant stress. Metabolites secreted to the rhizosphere by roots are involved in several processes. By modulating the composition of the root exudates, plants can modify soil properties to adapt and ensure their survival under adverse conditions. They use several strategies such as (1) changing soil pH to solubilize nutrients into assimilable forms, (2) chelating toxic compounds, (3) attracting beneficial microbiota, or (4) releasing toxic substances for pathogens, etc. In this work, the composition of root exudates as well as the different mechanisms of root exudation have been reviewed. Existing methodologies to collect root exudates, indicating their advantages and disadvantages, are also described. Factors affecting root exudation have been exposed, including physical, chemical, and biological agents which can produce qualitative and quantitative changes in exudate composition. Finally, since root exudates play an important role in the recruitment of mycorrhizal fungi and plant growth-promoting rhizobacteria (PGPR), the mechanisms of interaction between plants and the beneficial microbiota have been highlighted.

中文翻译：

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根系分泌物：从植物到根际及其他。

本文介绍了根系分泌物的组成、这些代谢物如何释放到根际以及它们在募集有益微生物群以减轻植物压力方面的重要性。由根分泌到根际的代谢物参与了几个过程。通过调节根系分泌物的成分，植物可以改变土壤特性以适应并确保它们在不利条件下生存。他们使用多种策略，例如 (1) 改变土壤 pH 值以将营养物质溶解成可吸收的形式，(2) 螯合有毒化合物，(3) 吸引有益微生物群，或 (4) 为病原体释放有毒物质等。在这项工作中，对根系分泌物的组成以及不同的根系分泌机制进行了综述。收集根分泌物的现有方法，还说明了它们的优点和缺点。影响根系分泌物的因素已经暴露出来，包括物理、化学和生物制剂，它们可以使分泌物成分产生质和量的变化。最后，由于根系分泌物在菌根真菌和植物促生根际细菌（PGPR）的募集中发挥重要作用，因此强调了植物与有益微生物群之间相互作用的机制。