Cation diffusion facilitators (CDFs) play central roles in metal homeostasis and tolerance in plants, but the specific functions of Camellia sinensis CDF-encoding genes and the underlying mechanisms remain unknown. Previously, transcriptome sequencing results in our lab indicated that the expression of CsMTP8.2 in tea plant shoots was down-regulated exposed to excessive amount of Mn²⁺ conditions. To elucidate the possible mechanisms involved, we systematically identified 13 C. sinensis CsMTP genes from three subfamilies and characterized their phylogeny, structures, and the features of the encoded proteins. The transcription of CsMTP genes was differentially regulated in C. sinensis shoots and roots in responses to high concentrations of Mn, Zn, Fe, and Al. Differences in the cis-acting regulatory elements in the CsMTP8.1 and CsMTP8.2 promoters suggested the expression of these two genes may be differentially regulated. Transient expression analysis indicated that CsMTP8.2 was localized to the plasma membrane in tobacco and onion epidermal cells. Moreover, when heterologously expressed in yeast, CsMTP8.2 conferred tolerance to Ni and Mn but not to Zn. Additionally, heterologous expression of CsMTP8.2 in Arabidopsis thaliana revealed that CsMTP8.2 positively regulated the response to manganese toxicity by decreasing the accumulation of Mn in plants. However, there was no difference in the accumulation of other metals, including Cu, Fe, and Zn. These results suggest that CsMTP8.2 is a Mn-specific transporter that contributes to the efflux of excess Mn²⁺ from plant cells.

阳离子扩散促进剂（CDF）在植物体内金属稳态和耐受性中起着核心作用，但是山茶CDF编码基因的特定功能和潜在机制尚不清楚。以前，我们实验室中的转录组测序结果表明，暴露于过量的Mn ²⁺条件下，茶树苗中CsMTP8.2的表达下调。为了阐明涉及的可能机制，我们系统地从三个亚科中鉴定了13个中华。CsMTP基因，并对它们的系统发育，结构和编码蛋白的特征进行了表征。CsMTP基因的转录在中华绒螯蟹中被不同地调节。对高浓度的Mn，Zn，Fe和Al的芽和根。在差异顺式作用在调节元件CsMTP8.1和CsMTP8.2启动子建议这两个基因的表达可被差异调节。瞬时表达分析表明，CsMTP8.2位于烟草和洋葱表皮细胞的质膜上。此外，当在酵母中异源表达时，CsMTP8.2赋予了对Ni和Mn的耐受性，但对Zn没有耐受性。此外，CsMTP8.2在拟南芥中的异源表达表明，CsMTP8.2通过减少植物体内锰的积累，积极调节了对锰毒性的反应。但是，包括Cu，Fe和Zn在内的其他金属的积累没有差异。这些结果表明，CsMTP8.2是一种Mn特异性转运蛋白，有助于植物细胞中过量Mn ²⁺的外流。