Amino acids are not only a nitrogen source that can be directly absorbed by plants, but also the major transport form of organic nitrogen in plants. A large number of amino acid transporters have been identified in different plant species. Despite belonging to different families, these amino acid transporters usually exhibit some general features, such as broad expression pattern and substrate selectivity. This review mainly focuses on transporters involved in amino acid uptake, phloem loading and unloading, xylem-phloem transfer, import into seed and intracellular transport in plants. We summarize the other physiological roles mediated by amino acid transporters, including development regulation, abiotic stress tolerance and defense response. Finally, we discuss the potential applications of amino acid transporters for crop genetic improvement.

中文翻译：

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植物细胞中的氨基酸转运蛋白：简述。

氨基酸不仅是植物可以直接吸收的氮源，而且还是植物中有机氮的主要运输形式。在不同的植物物种中已经鉴定出大量的氨基酸转运蛋白。尽管属于不同的家族，但这些氨基酸转运蛋白通常表现出一些一般特征，例如广泛的表达模式和底物选择性。这项审查主要侧重于氨基酸吸收，韧皮部加载和卸载，木质部-韧皮部转移，导入种子和植物中细胞内运输所涉及的转运蛋白。我们总结了氨基酸转运蛋白介导的其他生理作用，包括发育调节，非生物胁迫耐受性和防御反应。最后，我们讨论了氨基酸转运蛋白在作物遗传改良中的潜在应用。