Lace Plants Illustrate Programmed Cell Death

Scientists from Dalhousie University in Canada presented the first documentation of the physiological occurrences in aquatic lace plant (Aponogeton madagascariensis) involving programmed cell death (PCD). PCD is a highly regulated process that occurs in all animals and plants as part of normal development and in response to the environment.

Arunika Gunawardena and team used long-term live cell imaging, time-lapse micro photography and detailed staining to observe the whole process. They found that PCD always starts in the areas surrounded by veins and works its way out, finally halting four or five cells away from the vein. The non-PCD cells were pink but as PCD progresses the color disappears but the chlorophyll remains. At the latter stage of PCD, both pink and green pigments have been lost.

Gunawardena continued, "For each cell we observed, eventually the tonoplast ruptured, and the plasma membrane surrounding the cell collapsed. It only takes 48 hours from the first noticeable loss in chlorophyll until the plasma membrane shrinks, and by 24 hours after this event the cell wall disappears."

Read the research article at http://www.biomedcentral.com/1471-2229/12/115/abstract.