Colorado State University, Biology Department, Fort Collins, CO 80523, USA.
Colorado State University, Biology Department, Fort Collins, CO 80523, USA.
J Hazard Mater. 2021 Feb 15;404(Pt B):124178. doi: 10.1016/j.jhazmat.2020.124178. Epub 2020 Oct 6.
The aim of this review is to synthesize current knowledge of selenium (Se) transport and metabolism in plants, with a focus on implications for biofortification and phytoremediation. Selenium is a necessary human micronutrient, and around a billion people worldwide may be Se deficient. This can be ameliorated by Se biofortification of staple crops. Selenium is also a potential toxin at higher concentrations, and multiple environmental disasters over the past 50 years have been caused by Se pollution from agricultural and industrial sources. Phytoremediation by plants able to take up large amounts of Se is an important tool to combat pollution issues. Both biofortification and phytoremediation applications require a thorough understanding of how Se is taken up and metabolized by plants. Selenium uptake and translocation in plants are largely accomplished via sulfur (S) transport proteins. Current understanding of these transporters is reviewed here, and transporters that may be manipulated to improve Se uptake are discussed. Plant Se metabolism also largely follows the S metabolic pathway. This pathway is reviewed here, with special focus on genes that have been, or may be manipulated to reduce the accumulation of toxic metabolites or enhance the accumulation of nontoxic metabolites. Finally, unique aspects of Se transport and metabolism in Se hyperaccumulators are reviewed. Hyperaccumulators, which can accumulate Se at up to 1000 times higher concentrations than normal plants, present interesting specialized systems of Se transport and metabolism. Selenium hyperaccumulation mechanisms and potential applications of these mechanisms to biofortification and phytoremediation are presented.
本综述旨在综合当前植物中硒（Se）运输和代谢的知识，重点关注其对生物强化和植物修复的影响。硒是人体必需的微量元素，全球约有 10 亿人可能存在硒缺乏的问题。通过主食作物的硒生物强化可以改善这种情况。硒在较高浓度下也是一种潜在的毒素，过去 50 年发生的多次环境灾难都是由农业和工业来源的硒污染引起的。能够大量吸收硒的植物的植物修复是解决污染问题的重要手段。生物强化和植物修复应用都需要深入了解硒是如何被植物吸收和代谢的。植物中的硒摄取和转运主要通过硫（S）转运蛋白来完成。本文回顾了这些转运蛋白的当前认识，并讨论了可能被操纵以提高硒吸收的转运蛋白。植物中的硒代谢也主要遵循 S 代谢途径。本文综述了这一途径，特别关注了那些已经或可能被操纵以减少有毒代谢物积累或增强无毒代谢物积累的基因。最后，本文还回顾了硒超积累植物中硒运输和代谢的独特方面。硒超积累植物可以将硒积累到比正常植物高 1000 倍的浓度，它们表现出有趣的硒运输和代谢的特殊系统。本文介绍了硒超积累的机制，以及这些机制在生物强化和植物修复中的潜在应用。
