Ca2+调控柑橘属果实分泌囊细胞凋亡的作用机制研究

Secretory cavity is a common structure of Citrus, The research of secretory cavity in Citrus on the origin, ontogeny and developmental types had a lot of systematical achievements, but as a material to study the plant developmental programmed cell death (PCD), which is reported recently, the relevant signaling molecules and regulation mechanism are unclear. It has previously proved that the PCD process is involved in the degradation of secretory cells in Citrus sinensis (L.) Osbeck fruits, and the temporal and spatial location of calcium is closely related to the secretory cells PCD. Calcium, as the activity ion which endonucleases depend on, is mainly to activate DNase, which assist to remove the nucleus and degrade the nuclear DNA during Programmed cell death (PCD). In order to explore the function of calcium in secretory cavity PCD, we combined the cytology, molecular biology and biochemistry to analyze the location and function of Ca2+ dependent DNase. It will provide new evidence to Ca2+ in the degradation of nuclear DNA in secretory cells PCD, and new data to further explore the mechanism underlying calcium regulation of nuclear DNA degradation in plant PCD.

分泌囊是柑橘属（Citrus）植物普遍具有的结构特征，有关柑橘属植物分泌囊的起源、发生及发育类型的研究已有系统报道，但其作为植物发育性细胞程序性死亡（Programmed cell death, PCD）的研究材料是近年来才提出的一个新的实验体系，相关的信号分子和调控机理都还不清楚。研究表明PCD过程参与了甜橙果实分泌囊细胞的降解，钙离子的时空变化也与分泌囊细胞PCD过程密切相关。钙作为核酸内切酶依赖的活性离子，在PCD中的主要作用是激活DNase，进而协助完成细胞核的清除、核DNA的降解。为了探讨钙离子在柑橘属果实分泌囊细胞PCD过程中的具体功能和作用，本项目拟采用细胞生物学与分子生物学相结合的方法，综合分析钙依赖DNase在PCD过程中的定位、动态变化及其功能。为研究钙离子参与分泌囊细胞PCD中核DNA降解的作用机制提供新的证据，为进一步深入探讨植物细胞PCD的分子机理提供科学的资料。