Abstract

Flotillin membrane proteins are involved in many cellular processes and physiological functions. However, these proteins’ participation in plant response to stresses remains poorly understood. In the present report, the possible involvement of flotillin Flot1 in Na⁺ and K⁺ homeostasis in cells under sodium chloride salinization of the medium was studied in Arabidopsis thaliana (L.) Heynh. For this purpose, the Flot1 gene transcription was analyzed in the roots and leaves of wild-type (WT) and flot1 mutant plants with a T-DNA insertion in the promoter using the quantitative Real Time-RT PCR (qRT-PCR). Along with this, a mutant phenotype was studied (growth characteristics, content of Na⁺ and K⁺ ions in organs, and ultrastructure of root cells) under normal conditions and in the presence of 100 mM NaCl in the culture medium. The mutation led to the activation of AtFlot1 expression, which was more noticeable in the roots during salinization. Under these conditions, the mutants had larger organ mass, lower Na⁺ content, and higher K⁺ content in organs than that of WT. The study of the ultrastructure of A. thaliana root cells in mutant plants showed more intensive formation of post-Golgi vesicles and multivesicular bodies (MVB) in the cytoplasm. In both mutant and WT plants, the presence of sodium chloride in the nutrient solution stimulated the formation of MVB and microvacuoles in the cytoplasm and fusion of the latters into larger structures. It is assumed that changes in the ultrastructure of root cells that are caused by mutation and salinization reflect the stimulation, respectively, of vesicular trafficking and biogenesis of vacuoles—processes involved in maintaining Na⁺ and K⁺ cell homeostasis.

中文翻译：

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在Flot1（At5g25250）基因启动子中具有T-DNA插入的拟南芥突变体具有增强的对NaCl的抗性

摘要

絮凝膜蛋白参与许多细胞过程和生理功能。但是，这些蛋白质参与植物对逆境的反应仍知之甚少。在本报告中，在拟南芥Heynh中研究了在培养基的氯化钠盐化下，弗洛蒂林Flot1可能参与细胞的Na ⁺和K ⁺稳态。为此，使用实时定量RT PCR（qRT-PCR）分析了在启动子中插入T-DNA的野生型（WT）和flot1突变植物的根和叶中的Flot1基因转录。同时，研究了突变表型（生长特性，Na ^+的含量在正常条件下，在培养基中存在100 mM NaCl的情况下，器官中的K ⁺和K ⁺离子，以及根细胞的超微结构）。该突变导致AtFlot1表达的激活，这在盐碱化过程中在根部更为明显。在这种条件下，突变体比野生型具有更大的器官质量，更低的Na ⁺含量和更高的K ⁺含量。拟南芥的超微结构研究突变植物中的根细胞在细胞质中显示出高强度的高尔基后小泡和多囊泡体（MVB）形成。在突变植物和野生型植物中，营养液中氯化钠的存在刺激了细胞质中MVB和微血管的形成以及后者融合成更大的结构。据推测，由突变和盐碱化引起的根细胞超微结构的变化分别反映了水泡运输和液泡生物发生的刺激，这些过程涉及维持Na ⁺和K ⁺细胞的体内平衡。