Calcium inhibition halts developmental programmed cell death in the lace plant, Aponogeton madagascariensis?

This study examined the effect of the calcium channel blocker ruthenium red (RR) on developmental programmed cell death (PCD) and perforation formation in leaves of the aquatic lace plant (Aponogeton madagascariensis (Mirbel) H. Bruggen). Plant immersion experiments were conducted using various concentrations (0, 10, 20, 30, and 40 μmol L^-1) of RR applied to whole plants over a 3 to 4 week period. The ratio of number of leaf perforations per centimetre of leaf length along with leaf length were used to assess treatment effect. While the ratio of number of perforations per centimetre of leaf length was significantly reduced with RR treatment, leaf length was not, overall, significantly affected by RR. Therefore, it was concluded that RR was able to inhibit calcium movement and halt PCD, thus reducing perforation formation without having detrimental effects on leaf growth. The present research provides indirect evidence of the possible role of calcium in developmental PCD in vivo during leaf morphogenesis in the lace plant. Furthermore, it suggests the usefulness of the lace plant as a model system for pharmacological studies involving developmental PCD.