College of Agricultural, Guizhou University, Guiyang 550025, China.
Institute of Agro-Bioengineering of Guizhou University, Guiyang 550025, China; Key laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Guizhou University, Guiyang 550025, China; College of Life Sciences, Guizhou University, Guiyang 550025, China.
Ecotoxicol Environ Saf. 2021 Jan 15;208:111661. doi: 10.1016/j.ecoenv.2020.111661. Epub 2020 Nov 23.
NRAMP family genes participate in the absorption and transport of heavy metals such as cadmium (Cd), zinc (Zn), copper (Cu), lead (Pb), iron (Fe) and manganese (Mn) and play an important role in the response to heavy metal stress. There is an abundance of research on these genes in bacteria, plants and fungi, although not in S. tuberosum. A total of 48 members(potato(5), Arabidopsis(7), Tomato(9), pepper(9), rice(12) and tobacco(6)) were identified from 6 species (potato (Solanum tuberosum), Arabidopsis thaliana, Tomato (Solanum lycopersicum), pepper (Capsicum annuum), rice (Oryza sativa) and tobacco (Nicotiana attenuate)) and were classified into four subgroups. Across NRAMP gene family members, there are 15 highly conserved motifs that have similar genetic structures and characteristics. In addition, a total of 16 pairs of colinear genes were found in eight species. Analysis of cis-elements indicated that, in response to abiotic stress, NRAMPs are mainly regulated by phytohormones and transcription factors. In addition, analysis of expression profiles indicated that StNRAMP4 is mainly expressed in the roots. According to a qRT-PCR-based analysis of the StNRAMP family, with the exception of Pb stress, StNRAMPs positively responded to stress from Cu, Cd, Zn and Ni and The expression patterns is similar of StNRAMP2, under Pb, and Cu treatment, the relative expression peaked at 24 h. the relative expression peaked at 12 h and was upregulated 428-fold in the roots under Ni stress. Under Cd stress, StNRAMP3 was upregulated 28-fold in the leaves. StNRAMP1, StNRAMP4 and StNRAMP5 showed significant upregulation under Cu, Cd and Zn stress, respectively. Expression of StNRAMPs could be specifically induced by heavy metals, implying their possible role in the transport and absorption of heavy metals. This research explains the colinear characteristics of NRAMPs in several food crop species, which is useful for providing important genetic resources for cultivating food crop that accumulate low amounts of heavy metals and for explaining the biological functions of NRAMPs in plants.
NRAMP 家族基因参与镉（Cd）、锌（Zn）、铜（Cu）、铅（Pb）、铁（Fe）和锰（Mn）等重金属的吸收和转运，在重金属胁迫响应中发挥重要作用。尽管在马铃薯（Solanum tuberosum）中没有研究，但在细菌、植物和真菌中对这些基因进行了大量研究。从 6 个物种（马铃薯（Solanum tuberosum）、拟南芥（Arabidopsis thaliana）、番茄（Solanum lycopersicum）、辣椒（Capsicum annuum）、水稻（Oryza sativa）和烟草（Nicotiana attenuate））中共鉴定出 48 个成员（马铃薯（5）、拟南芥（7）、番茄（9）、辣椒（9）、水稻（12）和烟草（6）），并将其分为四个亚组。在 NRAMP 基因家族成员中，有 15 个高度保守的基序，它们具有相似的遗传结构和特征。此外，在 8 个物种中发现了总共 16 对共线性基因。顺式元件分析表明，NRAMP 主要受植物激素和转录因子调控，以应对非生物胁迫。此外，表达谱分析表明，StNRAMP4 主要在根部表达。根据基于 qRT-PCR 的马铃薯 StNRAMP 家族分析，除 Pb 胁迫外，StNRAMPs 对 Cu、Cd、Zn 和 Ni 胁迫均呈正响应，且表达模式与 Pb、Cu 处理下的 StNRAMP2 相似，相对表达量在 24 h 时达到峰值。在 Ni 胁迫下，相对表达量在 12 h 时达到峰值，在根部上调 428 倍。在 Cd 胁迫下，StNRAMP3 在叶片中上调 28 倍。StNRAMP1、StNRAMP4 和 StNRAMP5 分别在 Cu、Cd 和 Zn 胁迫下表现出显著上调。重金属可特异性诱导 StNRAMPs 的表达，表明其在重金属的运输和吸收中可能发挥作用。这项研究解释了几种粮食作物中 NRAMPs 的共线性特征，这对于提供积累低量重金属的粮食作物的重要遗传资源以及解释植物中 NRAMPs 的生物学功能具有重要意义。
