Reape Theresa J, McCabe Paul F
School of Biology and Environmental Science, University College Dublin, Dublin 4, Ireland.
New Phytol. 2008;180(1):13-26. doi: 10.1111/j.1469-8137.2008.02549.x.
Programmed cell death (PCD) is now accepted as a fundamental cellular process in plants. It is involved in defence, development and response to stress, and our understanding of these processes would be greatly improved through a greater knowledge of the regulation of plant PCD. However, there may be several types of PCD that operate in plants, and PCD research findings can be confusing if they are not assigned to a specific type of PCD. The various cell-death mechanisms need therefore to be carefully described and defined. This review describes one of these plant cell death processes, namely the apoptotic-like PCD (AL-PCD). We begin by examining the hallmark 'apoptotic-like' features (protoplast condensation, DNA degradation) of the cell's destruction that are characteristic of AL-PCD, and include examples of AL-PCD during the plant life cycle. The review explores the possible cellular 'executioners' (caspase-like molecules; mitochondria; de novo protein synthesis) that are responsible for the hallmark features of the cellular destruction. Finally, senescence is used as a case study to show that a rigorous definition of cell-death processes in plant cells can help to resolve arguments that occur in the scientific literature regarding the timing and control of plant cell death.
程序性细胞死亡（PCD）如今已被公认为植物中的一种基本细胞过程。它参与防御、发育以及对胁迫的响应，而通过更深入地了解植物PCD的调控，我们对这些过程的认识将得到极大提升。然而，植物中可能存在多种类型的PCD，如果不将PCD研究结果归为特定类型，可能会造成混淆。因此，需要仔细描述和定义各种细胞死亡机制。本综述描述了其中一种植物细胞死亡过程，即类凋亡程序性细胞死亡（AL-PCD）。我们首先考察细胞破坏过程中具有“类凋亡”特征（原生质体凝聚、DNA降解）的标志性特征，这些特征是AL-PCD所特有的，并列举植物生命周期中AL-PCD的实例。本综述探讨了可能导致细胞破坏标志性特征的细胞“执行者”（类半胱天冬酶分子；线粒体；从头蛋白质合成）。最后，以衰老为例进行研究，表明对植物细胞死亡过程进行严格定义有助于解决科学文献中关于植物细胞死亡时间和控制方面出现的争议。
