钙离子可能参与放线菌素D诱导的玉米细胞凋亡

钙在动物细胞凋亡的信号转导中起重要作用,其最直接的作用是激活钙依赖性核酸酶,导致DNA的特异片段化.然而,关于钙在植物细胞程序性死亡中的作用的报道很少.本文以玉米根尖分生组织为材料,利用RNA合成剂放线菌D诱导细胞死亡,并从形态和生化方面检测到这种细胞死亡是一种程序性死亡(programmed cell death,PCD).利用钙离子特异性结合荧光染料wazo-1研究的结果表明,在死亡程序启动的瞬间,胞质内钙离子浓度急骤上升.意味着钙信号转导途径可能参与了这种PCD.这种PCD在DNA严重断裂之前是可以逆转的.

Possible Involvement of Calcium in Actinomycin D Induced Apoptosis in Maize

Calcium is involved in several steps of the apoptotic process in animals. Endonucleases are presumed to be the main targets of calcium; however, little is known about its role during plant programmed cell death. In this study, maize root meristematic tissues were submitted to treatment with cytotoxic reagent, the RNA-synthesis inhibitor Actinomycin D (ActD). The morphological and biochemical evidence for apoptosis in individual treated cells was identified. Further, the involvement of calcium has been detected using specific Ca 2+ -binging fluorescent dye, wazo-1. The results indicated that treatment with ActD resulted in an immediate increase in intracellular calcium. The calcium-mediated death process could be reversed before serious DNA breakage.