Abstract

Aluminum (Al) toxicity is the main limiting factor of crop growth in acid soil. Plants can resist Al toxicity by regulating a series of mechanisms. Many physiological functions have been developed to improve the Al tolerance in plants which can be briefly outlined as two mechanisms. One such well-documented mechanism is external exclusion, which mainly reduces Al entry into cells, and the other one is the internal detoxification, consisting of the antioxidant defense system, the redistribution of Al³⁺ such as vacuolar compartmentalization, and the response of auxin. In external exclusion mechanism, with special emphasis on the mechanism of Al-induced organic acid secretion from roots, the current understanding of genes regulating organic acid secretion has been reviewed. In terms of the internal detoxification mechanism, we generalized the deposition and redistribution of Al in the cytoplasm, particularly, summarized the genes encoding Al³⁺ absorption and transport, and also discussed other possible mechanisms for improving plant tolerance to Al. Therefore, this review describes the recent research progress of Al tolerance mechanisms in plants, and provide future perspectives regarding more practical approaches for Al toxicity alleviation, which can create important social benefits and huge economic value for screening Al-tolerant plants and developing crop breeding.

摘要

铝（Al）毒性是酸性土壤中作物生长的主要限制因素。植物可以通过调控一系列机制来抵抗铝的毒性。已经开发了许多生理功能来提高植物对铝的耐受性，可以简要概括为两种机制。一种这样的有据可查的机制是外部排斥，主要减少 Al 进入细胞，另一种是内部解毒，包括抗氧化防御系统，Al ^{3+的重新分布}例如液泡区室化和生长素的反应。在外部排斥机制方面，特别强调了铝诱导根系有机酸分泌的机制，回顾了目前对调控有机酸分泌的基因的认识。在内部解毒机制方面，我们概括了Al在细胞质中的沉积和重新分布，特别是总结了编码Al ^{3+的基因。}吸收和运输，并讨论了提高植物对铝的耐受性的其他可能机制。因此，本综述介绍了植物对铝耐受机制的最新研究进展，并为未来更实用的铝毒性缓解方法提供了展望，这将为筛选耐铝植物和发展作物育种创造重要的社会效益和巨大的经济价值。