浮萍 Nramp 转运蛋白基因在镉积累中的作用。

Role of Nramp transporter genes of Spirodela polyrhiza in cadmium accumulation.

机构信息

The State Key Laboratory of Freshwater Ecology and Biotechnology, The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China; University of Chinese Academy of Sciences, Beijing 100049, China.

出版信息

Ecotoxicol Environ Saf. 2021 Dec 20;227:112907. doi: 10.1016/j.ecoenv.2021.112907. Epub 2021 Oct 19.

DOI:10.1016/j.ecoenv.2021.112907

PMID:34673410

Abstract

As a pollutant, Cd causes severe impact to the environment and damages living organisms. It can be uptaken from the environment by the natural resistance-associated macrophage protein (Nramp) in plants. However, the ion absorption function of Nramp transporter genes in Spirodela polyrhiza has not been reported. In this study, SpNramp1, SpNramp2, and SpNramp3 from S. polyrhiza were cloned and their functions were analyzed in S. polyrhiza and yeast. Growth parameters and physicochemical indices of wild-type and transgenic lines were measured under Cd stress. Results revealed that SpNramp1, SpNramp2, and SpNramp3 were identified as plasma membrane-localized transporters, and their roles in transporting Cd were verified in yeast. In S. polyrhiza, SpNramp1 overexpression significantly increased the content of Cd, Fe, Mn, and fresh weight. SpNramp2 overexpression increased Mn and Cd. SpNramp3 overexpression increased Fe and Mn concentrations. These results indicate that SpNramp1, SpNramp2, and SpNramp3 had a different preference for ion absorption. Two S. polyrhiza transgenic lines (OE1 and OE3) were obtained. One of them (OE1) showed a stronger accumulation ability, and the other one (OE3) exhibited tolerance capacity to Cd. This study provides new insight into the functions of SpNramp1, SpNramp2, and SpNramp3 and obtains important enrichment lines (OE1) for manipulating Cd accumulation, phytoremediation, and ecological safety.

摘要

作为一种污染物，Cd 对环境和生物造成严重影响。它可以通过植物中的天然抗性相关巨噬细胞蛋白（Nramp）从环境中摄取。然而，Spirulina polyrhiza 中 Nramp 转运体基因的离子吸收功能尚未报道。本研究从 Spirodela polyrhiza 中克隆了 SpNramp1、SpNramp2 和 SpNramp3，并在 Spirodela polyrhiza 和酵母中分析了它们的功能。在 Cd 胁迫下，测量了野生型和转基因系的生长参数和理化指标。结果表明，SpNramp1、SpNramp2 和 SpNramp3 被鉴定为定位于质膜的转运蛋白，并且在酵母中验证了它们在转运 Cd 方面的作用。在 Spirodela polyrhiza 中，SpNramp1 的过表达显著增加了 Cd、Fe、Mn 和鲜重的含量。SpNramp2 的过表达增加了 Mn 和 Cd。SpNramp3 的过表达增加了 Fe 和 Mn 的浓度。这些结果表明，SpNramp1、SpNramp2 和 SpNramp3 对离子吸收具有不同的偏好。获得了两个 Spirodela polyrhiza 转基因系（OE1 和 OE3）。其中一个（OE1）表现出更强的积累能力，另一个（OE3）表现出对 Cd 的耐受性。本研究为 SpNramp1、SpNramp2 和 SpNramp3 的功能提供了新的见解，并获得了用于操纵 Cd 积累、植物修复和生态安全的重要富集系（OE1）。