Plant‐to‐plant signalling is a key mediator of interactions among plant species. Plants can perceive and respond to chemical cues emitted from their neighbours, altering survival and performance, impacting plant coexistence and community assembly. An increasing number of studies indicate root exudates as key players in plant‐to‐plant signalling. Root exudates mediate root detection and behaviour, kin recognition, flowering and production, driving inter‐ and intra‐specific facilitation in cropping systems and mixed‐species plantations. Altered interactions may be attributed to the signalling components within root exudates. Root ethylene, strigolactones, jasmonic acid, (‐)‐loliolide and allantoin are signalling chemicals that convey information on local conditions in plant–plant interactions. These root‐secreted signalling chemicals appear ubiquitous in plants and trigger a series of belowground responses inter‐ and intra‐specifically, involving molecular events in biosynthesis, secretion and action. The secretion of root signals, mainly mediated by ATP‐binding cassette transporters, is critical. Root‐secreted signalling chemicals and their molecular mechanisms are rapidly revealing a multitude of fascinating plant–plant interactions. However, many root signals, particularly species‐specific signals and their underlying mechanisms, remain to be uncovered due to methodological limitations and root‐soil interactions. A thorough understanding of root‐secreted chemical signals and their mechanisms will offer many ecological implications and potential applications for sustainable agriculture.

中文翻译：

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植物-植物相互作用中的根系分泌物信号

植物间信号传导是植物物种间相互作用的关键介质。植物可以感知并响应邻居发出的化学信号，改变生存和性能，影响植物共存和群落组装。越来越多的研究表明根系分泌物是植物间信号传递的关键参与者。根系分泌物介导根系检测和行为、亲属识别、开花和生产，推动种植系统和混种种植园的种间和种内促进作用。改变的相互作用可能归因于根分泌物中的信号成分。根乙烯、独脚金内酯、茉莉酸、(-)-loliolide 和尿囊素是信号化学物质，可传达植物与植物相互作用中局部条件的信息。这些根分泌的信号化学物质在植物中无处不在，并引发一系列种间和种内的地下反应，涉及生物合成、分泌和作用中的分子事件。主要由 ATP 结合盒转运蛋白介导的根信号的分泌至关重要。根分泌的信号化学物质及其分子机制正在迅速揭示多种迷人的植物-植物相互作用。然而，由于方法学限制和根-土相互作用，许多根信号，特别是物种特异性信号及其潜在机制仍有待发现。彻底了解根系分泌的化学信号及其机制将为可持续农业提供许多生态意义和潜在应用。