Synthesis Metabolism and Compartmentation of Malate in MaizeRoots

玉米根尖苹果酸代谢和运输速率将采用核磁共振波谱结合其他生化技术进行测量。这些过程将在组织中量化，显示出不同的苹果酸合成速率，响应于钾离子的摄取，或铵离子的同化。将监测的具体反应包括(i)线粒体氧化利用糖酵解衍生的苹果酸；（ii） PEP羧化酶和苹果酸酶的作用，以及它们与克雷布斯循环和氨基酸生物合成活性的协调；苹果酸在细胞质和液泡之间的运动。联合测量将允许观察组成苹果酸代谢的不同组分之间的相互作用。这些信息是了解呼吸、矿物质营养、细胞内pH调节、氨基酸生物合成和生长的先决条件，特别是关于这些过程在体内的整合。＊＊＊

9310850 Roberts The rates of malate metabolism and transport in maize root tips will be measured using nuclear magnetic resonance spectroscopy in combination with other biochemical techniques. These processes will be quantitated in tissue exhibiting different rates of malate synthesis, in response to potassium ion uptake, or assimilation of ammonium ion. Specific reactions that will be monitored include (i) utilization of glycolytically-derived malate by mitochondria for oxidation; (ii) action of PEP carboxylase and malic enzyme, and their coordination with activity in the Krebs cycle and amino acid biosynthesis; (iii) movement of malate between cytoplasm and vacuole. The combined measurements will permit observation of interactions between the different components comprising malate metabolism. This information is a prerequisite to an understanding of respiration, mineral nutrition, intracellular pH regulation, amino acid biosynthesis and growth - particularly with respect to the integration of these processes in vivo. ***