The lace plant, Aponogeton madagascariensis, is an aquatic plant native to Madagascar. It has characteristic lacey leaves which are formed by programmed cell death (PCD) in the areoles between leaf veins. Wertman et al., from Dalhousie University, used the predictable nature of PCD in lace plants to monitor the process using light, confocal and standing electron microscopy. They were able to discern the precise order of organelle disruption and activity during PCD. They could even video the process using live cell imaging on a light microscope – you can see the cells rupture in front of your eyes in the video below.
Highlighted article: Jaime Wertman, Christina CEN Lord, Adrian N Dauphinee and Arunika HLAN Gunawardena (2012) The pathway of cell dismantling during programmed cell death in lace plant (Aponogeton madagascariensis) leaves. BMC Plant Biology 2012, 12:115
The paper is quite straightforward and a nice one to read so I won’t go in to detail here, but I will quickly go over their findings. After initial anthocyanin reduction, which is how the team identified accurately where and when PCD would take place, the first phase of activity included the bundling of actin microfilaments, and transvacuolar strands increased in number. Then the tonoplast membrane began to fold and mitochondrial aggregates and chloroplasts moved randomly. Nuclear DNA, actin microfilaments and the cell wall broke up. The vacuole swelled and its membrane ruptured while the nucleus shrank and the plasma membrane collapsed. The whole process took roughly 48 hours, and it took more than 24 more hours before the cell wall completely disappeared.