过敏性坏死反应是植物的一种重要的抗病机制, 类似于动物细胞凋亡, 它是一种程序性细胞死亡(programmed cell death, PCD)过程。目前, 已经确定半胱天冬蛋白酶(caspase)在动物PCD过程中起核心作用。在植物中, 尚未发现其直系同源蛋白, 但是有一类与其结构相似的蛋白酶, 称为metacaspase。在植物不同的PCD过程中, 有的依赖于metacaspase, 而有的则不依赖于该类蛋白酶。目前对metacaspase的结构和功能已有了初步的研究, 对其深入的研究则进展缓慢, 其具体的生物学功能和在PCD信号路径中的定位有待进一步探索。

The hypersensitive reaction is an important process in plant disease resistance. Similar to apoptosis in animals, it is programmed cell death (PCD) process in plants. Caspases (cysteine-dependent aspartate-specific proteases) play a central role in animal apoptotic pathways. No orthologous proteins of caspases have been found in plants, but a group of proteins with similar structures, termed metacaspases, have been found. In plants, some PCD processes depend on metacaspases, and others do not. We discuss researches into the structure and function of metacaspases. The biological functions of metacaspases and their roles in PCD pathways in plants remain to be explored.