Robe Kevin, Lefebvre-Legendre Linnka, Cleard Fabienne, Barberon Marie
Department of Plant Sciences, University of Geneva, Geneva, Switzerland.
PLoS Genet. 2025 Jul 15;21(7):e1011796. doi: 10.1371/journal.pgen.1011796. eCollection 2025 Jul.
Zinc (Zn), an essential micronutrient, plays a crucial role in plant development. However, the specific transporters involved in Zn uptake from the soil remain unclear in dicotyledonous plants. Using promoter-reporter lines in Arabidopsis thaliana, we identified several ZIP (Zn-regulated transporter, Iron-regulated transporter (IRT)-like Protein) family members that are expressed in the epidermis and potentially involved in Zn acquisition from the outer root domain. ZIP2, ZIP3, ZIP5 and ZIP8 predominantly localize to the plasma membrane of epidermal and cortical cells, supporting their potential roles in metal uptake from the soil. Through physiology studies, ionomic profiling and genetic analysis, we determined that ZIP3 and ZIP5 are contributors to Zn acquisition, while ZIP2 and ZIP8 are primarily involved in copper (Cu) and iron (Fe) acquisition respectively. Notably, ZIP3 and ZIP8 exhibit outer polarity in root epidermal cells, similar to IRT1, in agreement with expectations of transporter polarity in mineral acquisition. These findings provide new insights into the mechanisms of metal uptake in plant roots and offer potential strategies for biofortification to enhance metal content in plants.
锌（Zn）作为一种必需的微量营养素，在植物发育过程中起着至关重要的作用。然而，在双子叶植物中，参与从土壤中吸收锌的具体转运蛋白仍不清楚。利用拟南芥中的启动子-报告基因系，我们鉴定出了几个ZIP（锌调节转运蛋白、铁调节转运蛋白（IRT）样蛋白）家族成员，它们在表皮中表达，并可能参与从根外层区域获取锌。ZIP2、ZIP3、ZIP5和ZIP8主要定位于表皮和皮层细胞的质膜，这支持了它们在从土壤中吸收金属方面的潜在作用。通过生理学研究、离子组学分析和遗传分析，我们确定ZIP3和ZIP5有助于锌的获取，而ZIP2和ZIP8分别主要参与铜（Cu）和铁（Fe）的获取。值得注意的是，ZIP3和ZIP8在根表皮细胞中表现出外向极性，类似于IRT1，这与矿物质获取中转运蛋白极性的预期一致。这些发现为植物根系吸收金属的机制提供了新的见解，并为生物强化以提高植物中的金属含量提供了潜在策略。
