STUDIES ON THE ROLE OF VACUOLES IN ION METABOLISMS IN PLANT.

液泡在植物离子代谢中作用的研究。

• 批准号: 09044211
• 负责人: MIMURA Tetsuro
• 金额: $ 3.26万
• 依托单位: HITOTSUBASHI UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09044211/
• 关键词: Cell membrane; Tonoplast; Characeae; Inorganic phosphate; Barley; H^+-ATPase; Inorganic ion; Plant nutrition; ナトリウム(Na)

In inorganic ion metabolisms in plant cells, vacuole is one of the most important organelles. The vacuole is usually working as ion reservoir and buffer f or the cytoplasmic ion homeostasis. For these functions, the tonoplast ion transport systems are playing important roles. In the present project, we tried to totally analyze the role of the vacuole in inorganic ion metabolisms in plant cells by means of physiology to molecular biology.Last year, we have measured Pi uptake of isolated barley mesophyll vacuoles. Unfortunately, Pi uptake activity of barley vacuole is not high. Thus, we have tried to measure the Pi uptake activity of suspension cultured cells of Catharanthus roseus. These cells are known to have high activities of Pi uptake in both the plasma membrane and the tonoplast. As well as barley, Catharanthus vacuoles showed both ATP and PPi dependent Pi uptake. Pi uptake lineally increased until 20 mM extravacuolar Pi. Bafilomycin ; a specific inhibitor of the tonoplast H^+-ATPase also inhibited Pi uptake across the tonoplast. All these data suggested that Pi might be transported across the tonoplast driven by the membrane potential. Since the tonoplast H^+-ATPase is an important factor, we further analyzed the redox control of the tonoplast H^+-ATPase.We are also measuring the relationship between Pi transport network across the plasma membrane and the tonoplst using isolated Chara internodal cells.

在植物细胞中无机离子代谢中，液泡是最重要的细胞器之一。该液泡通常用作离子库和缓冲液或细胞质离子稳态。对于这些功能，托管离子运输系统正在扮演重要角色。在本项目中，我们试图通过生理学对分子生物学的方式完全分析液泡在植物细胞中无机离子代谢中的作用。年份，我们已经测量了对孤立的大麦叶叶藻液泡的摄取。不幸的是，大麦液泡的PI吸收活动不高。因此，我们试图测量Catharanthus roseus悬浮培养的细胞的PI摄取活性。已知这些细胞在质膜和块状体中都具有较高的PI吸收活性。除大麦外，Catharanthus液泡均显示出ATP和PPI依赖性PI摄取。 PI摄取直至20毫米室外PI。巴菲霉素； Tonoplast H^+ATPase的特定抑制剂也抑制了整个块状体的PI摄取。所有这些数据都表明，PI可能会在膜电位驱动的整个块状物质上运输。由于TONOPLAST H^+ATPase是一个重要因素，因此我们进一步分析了托管H^+-ATPase的氧化还原对照。我们还使用隔离的Chara肠膜间室细胞来测量跨质膜的PI传输网络与托管之间的关系。

项目成果

Mimura T., Reid R.J., Smith F.A.: "Control of phosphate transport across the plasma membrane of Chara corallina." Journal of Experimental Botany. 49. 13-19 (1998)

Mimura T.、Reid R.J.、Smith F.A.：“控制磷酸盐跨珊瑚藻质膜的运输。”

Dietz K.J.: "Modulation of the vacuolar H^+-ATPase by adenylates as basis for the transient CO,-dependent acidification of the leafvacude uponillumination." Biochim.Biophys.Acta. 1373. 87-92 (1998)

Dietz K.J.：“腺苷酸对液泡 H2-ATP 酶的调节是光照时叶真空短暂 CO2 依赖性酸化的基础。”

Mimura T.: "Regulation of phosphate transport and homeostasis in plant cells." International Review of Cytology. (in press). (1999)

Mimura T.：“植物细胞中磷酸盐运输和稳态的调节。”