ZmPCK2在玉米籽粒氨基酸卸载过程中的作用及其调控

About 80% carbohydrate and 1.5% N were accumulated during maize kernel development. Both C and N metabolite signals, and their relative ratios, can affect whole plant source/sink relations,and also directly affect its production and quality. Phosphoenolpyruvate carboxykinase (PEPCK) played a vital role in the interconversion of amino acids, sugar and lipid. It was found to be located in vascular system of seeds from sevel plants. Two isoforms of PEPCK, ZmPCK1 and ZmPCK2, were found in our previous research, among which ZmPCK2 was never reported in other studies. This research presents a study of the biological role that ZmPCK2 plays in the amino acids unloading and metabolism in maize kernel.Studies on relationship between the post-translational modification and enzyme activity of ZmPCK2 are also carried on.The regulation network will be revealed through the discovery of proteins interacting with it by biochemistry and protein methods.This work will extremely contribute to the elucidation of potential biological role of ZmPCK2 in maize kernel and the vital roles that it plays in the regulation of photosynthetic products unloading from source to sink.

玉米在籽粒形成过程中，积累了大约80%的碳和1.5%的氮。碳氮代谢信号及碳氮比例直接影响植物的源/库关系，从而影响玉米的品质和产量。磷酸烯醇式丙酮酸羧激酶（PEPCK）在氨基酸、糖和脂类的相互转化中起着重要作用。已发现在多种植物种子的维管系统中表达。我们的前期工作表明玉米的PEPCK存在两个异构体ZmPCK1和ZmPCK2，其中ZmPCK2未见报道。本项目拟研究ZmPCK2在参与种子中氨基酸的卸载及代谢中的生物学作用；研究其蛋白质翻译后修饰与其酶活性的关系；利用生物化学方法与蛋白质技术研究其在种子中与其相互作用的蛋白揭示其调控网络。本项目的研究工作对于阐明玉米种子中ZmPCK2的潜在生物学功能，揭示其在调节光合产物在玉米从"源"到"库"卸载过程中的重要作用具有重要意义。