Determining the effect of calcium on cell death rate and perforation formation during leaf development in the novel model system, the lace plant (Aponogeton madagascariensis).

Abstract

Programmed cell death (PCD) is the destruction of unwanted cells through an intracellularly mediated process. Perforation formation in the lace plant (Aponogeton madagascariensis) provides an excellent model for studying developmentally regulated PCD. Ca2+ fluxes have previously been identified as important signals for PCD in plants and mammals. The fundamental goal of this project was to determine the influence of Ca2+ on the rate of cell death and perforation formation during leaf development in the lace plant. This was investigated using the application of various known calcium modulators including lanthanum III chloride (LaCl3 ), ruthenium red and calcium ionophore A23187. Detached lace plant leaves at an early stage of development were treated with these modulators in both short- and long-term exposure assays and analysed using live cell imaging. Results from this study indicate that calcium plays a vital role in developmentally regulated PCD in the lace plant as application of the modulators significantly altered the rate of cell death and perforation formation during leaf development. In conclusion, this study exemplifies the suitability of the lace plant for live cell imaging and detached leaf experiments to study cell death and provides insight into the importance of Ca2+ in developmentally regulated PCD in planta.