Nitric oxide (NO) is essential for plant growth and development, as well as interactions with abiotic and biotic environments. Its importance for multiple functions in plants means that tight regulation of NO concentrations is required. This is of particular significance in roots, where NO signalling is involved in processes, such as root growth, lateral root formation, nutrient acquisition, heavy metal homeostasis, symbiotic nitrogen fixation and root–mycorrhizal fungi interactions. The NO signal can also be produced in high levels by microbial processes in the rhizosphere, further impacting root processes. To explore these interesting interactions, in the present review, we firstly summarize current knowledge of physiological processes of NO production and consumption in roots and, thereafter, of processes involved in NO homeostasis in root cells with particular emphasis on root growth, development, nutrient acquisition, environmental stresses and organismic interactions.

中文翻译：

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球根一氧化氮对根系生长，发育和生物相互作用的生理意义。

一氧化氮（NO）对于植物生长和发育以及与非生物和生物环境的相互作用至关重要。它对植物中多种功能的重要性意味着需要严格调节NO的浓度。这在根中尤为重要，因为根中没有信号传导，例如根生长，侧根形成，养分获取，重金属稳态，共生固氮和根-菌根真菌相互作用。根际中的微生物过程也可能大量产生NO信号，从而进一步影响根系过程。为了探索这些有趣的相互作用，在本综述中，我们首先总结当前对根中NO产生和消耗的生理过程的了解，然后，