CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650223, China.
The College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.
Metallomics. 2024 Nov 7;16(11). doi: 10.1093/mtomcs/mfae047.
Iron (Fe) and Zinc (Zn) are essential micronutrients for plant growth and development. ZIP (ZRT, IRT-like protein) transporters, known for their role in the regulation of Zinc and Iron uptake, are pivotal in facilitating the absorption, transport, and maintenance of Fe/Zn homeostasis in plants. Nicotiana tabacum has been widely used as a model plant for gene function analysis; however, the tobacco ZIP genes have not been identified systematically. In this study, we have identified a comprehensive set of 32 NtZIP genes, which were phylogenetically categorized into three distinct clades. The gene structures, characterized by their exon/intron organization, and the protein motifs are relatively conserved, particularly among genes within the same clade. These NtZIP genes exhibit an uneven distribution across 12 chromosomes. The gene localization analysis revealed the presence of 11 pairs of homeologous locus genes and 7 pairs of tandem duplication genes within the genome. To further explore the functionality of these genes, real-time quantitative reverse transcription PCR was employed to assess their expression levels in roots subjected to metal deficiency. The results indicated that certain NtZIP genes are specifically upregulated in response to either Fe or Zn deficiency. Additionally, the presence of specific cis-elements within their promoter regions, such as the E-box associated with Fe deficiency response and the ZDRE box linked to Zn deficiency response, was identified. This study lays a foundational groundwork for future research into the biological functions of NtZIP genes in tobacco in micronutrient regulation and homeostasis.
铁（Fe）和锌（Zn）是植物生长和发育所必需的微量营养素。ZIP（ZRT、IRT 样蛋白）转运蛋白以其在锌和铁吸收调节中的作用而闻名，对于促进植物中铁/锌的吸收、转运和维持稳态至关重要。烟草（Nicotiana tabacum）已被广泛用作基因功能分析的模式植物；然而，烟草的 ZIP 基因尚未被系统地鉴定。在这项研究中，我们鉴定了一组全面的 32 个 NtZIP 基因，这些基因在系统发育上分为三个不同的分支。基因结构，其外显子/内含子组织的特点，以及蛋白质基序相对保守，特别是在同一分支内的基因之间。这些 NtZIP 基因在 12 条染色体上不均匀分布。基因定位分析显示，在基因组中存在 11 对同源基因和 7 对串联重复基因。为了进一步探索这些基因的功能，我们采用实时定量 RT-PCR 评估了它们在根中对金属缺乏的表达水平。结果表明，某些 NtZIP 基因在对 Fe 或 Zn 缺乏的反应中特异性地上调。此外，在其启动子区域内存在特定的顺式元件，如与 Fe 缺乏反应相关的 E 盒和与 Zn 缺乏反应相关的 ZDRE 盒。这项研究为未来研究烟草中 NtZIP 基因在微量元素调节和稳态中的生物学功能奠定了基础。
