Excess fluoride (F−) inhibits the growth and metabolism of several crop plants, while some have an innate ability for F− tolerance. The present study was undertaken to explain how plants tolerate F− toxicity and understand the efficacy of exogenous stress protectants and phytoremediation approaches for F− homeostasis and tolerance of crop plants. This review comprehends existing information available so far on the F− accumulation toxicity and tolerance mechanisms. A high level of F− inhibits plant growth, water and nutrition uptake, enzyme activity, and yield. This review concludes that plants tolerate through F− homeostasis (exclusion, chelating, and compartmentalization) and gene activation for enhanced pathways of antioxidants, hormones, osmolytes, stress proteins, transporters, and metabolites. Exogenously applied stress protectants like salicylic acid (SA), polyamines (PAs), melatonin (Mel), glycine betaine, calcium (Ca2+), and nanoparticles are differentially effective in reducing F− accumulation and toxicity by regulating various pathways. Application of minerals minimizes the F− accumulation through changing pH of soil, chelate formation with F−, and permeability of the cell membrane. Although many of the physiological aspects (enzyme activities, F− accumulation and regulation) were studied earlier, however, an effort has been made for the first time to understand the genetic basis and role of stress protectants and mineral nutrition, regulating these physiological activities, and explore new integrated approaches related to F− mitigation by means of phytoremediation. This review covers the recent development in F− transporters, gene expression, and biochemical and hormonal levels which could be utilized in regulating F− toxicity through omics and transgenic approaches in the future.

中文翻译：

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了解植物中氟化物的积累、毒性和耐受机制的最新进展：概述

过量的氟化物 (F-) 会抑制几种作物的生长和代谢，而有些植物具有先天的 F- 耐受能力。本研究旨在解释植物如何耐受 F- 毒性，并了解外源胁迫保护剂和植物修复方法对 F- 稳态和作物植物耐受性的功效。本综述涵盖了迄今为止关于 F− 积累毒性和耐受机制的现有信息。高水平的 F− 会抑制植物生长、水分和营养吸收、酶活性和产量。这篇综述得出的结论是，植物通过 F− 稳态（排斥、螯合和区室化）和基因激活来耐受抗氧化剂、激素、渗透物、应激蛋白、转运蛋白和代谢物的增强途径。外源性应用的应激保护剂，如水杨酸 (SA)、多胺 (PAs)、褪黑激素 (Mel)、甘氨酸甜菜碱、钙 (Ca2+) 和纳米颗粒，通过调节各种途径在减少 F− 积累和毒性方面的效果不同。矿物质的应用通过改变土壤的 pH 值、与 F- 形成螯合物以及细胞膜的渗透性来最大限度地减少 F- 的积累。尽管早期研究了许多生理方面（酶活性、F-积累和调节），但是，首次努力了解应激保护剂和矿物质营养的遗传基础和作用，调节这些生理活动，并通过植物修复探索与 F− 缓解相关的新综合方法。这篇综述涵盖了 F-转运蛋白的最新发展，