Physiology and Biochemistry of Calcium Oxalate Formation in Plants

植物中草酸钙形成的生理学和生物化学

• 批准号: 8919341
• 负责人: Vincent Franceschi
• 金额: --
• 依托单位: Washington State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-06-01 至 1993-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8919341&HistoricalAwards=false
• 关键词: Physiology; Biochemistry; Calcium; Oxalate; Formation

Calcium oxalate formation is pervasive in plants and can account for the preponderance of calcium in plant organs. Little is known about the physiology and biochemistry of this form of calcium compartmentation. A procedure has been developed to isolate calcium oxalate-forming cells (crystal idioblasts) as protoplasts from Pistia stratiotes. Using this system soluble and insoluble proteins of crystal idioblast and mesophyll protoplasts will be compared by gel electrophoresis to identify idioblast-specific proteins. Protein components of the specialized crystal chamber membranes and possible existence of crystal matrix proteins will also be explored. Biosynthetic pathways for oxalate synthesis in idioblasts and mesophyll cells will be determined. Calcium binding proteins will be identified on gels and blots by standard techniques. Characteristics of calcium uptake by crystal idioblast and mesophyll protoplasts will be determined by exposure to 45Ca (with and without inhibitors of calcium channels, calmodulin, and ATPases) followed by silicone oil centrifugation. These studies will provide valuable information, unobtainable by other means, about mechanisms and regulation of calcium oxalate formation in plants and will further our understanding of the importance of this phenomenon to calcium metabolism of plant tissues.

草酸钙的形成在植物中普遍存在，可以解释植物器官中钙的优势。人们对这种形式的钙室隔的生理和生物化学知之甚少。已开发出一种从水仙草中分离草酸钙形成细胞(晶体成纤维细胞)作为原生质体的方法。利用该系统对晶体原生质体和叶肉原生质体内的可溶性和不溶性蛋白质进行凝胶电泳法比较，以鉴定成纤维细胞特有的蛋白质。还将探讨特殊晶室膜的蛋白质成分以及晶体基质蛋白质的可能存在。将确定在成体细胞和叶肉细胞中合成草酸的生物合成途径。钙结合蛋白将通过标准技术在凝胶和印迹上识别。晶体成纤维细胞和叶肉原生质体吸收钙的特性将通过暴露于45Ca(有或没有钙通道、钙调蛋白和ATPase抑制剂)和硅油离心法来确定。这些研究将为了解植物草酸钙的形成机制和调控机制提供有价值的信息，并将进一步加深我们对这一现象对植物组织钙代谢的重要性的理解。