Hood, Nathan , Butterfield, Timothy , Reichler, Stuart , Roux, Stanley .
The Effect of Extracellular ATPyS on the Growth of Medicago truncatula Pollen Tubes.
Extracellular ATP has been shown to affect the growth of Arabidopsis pollen tubes. Lower concentrations of an unhydrolyzable form of ATP (ATPyS) promote the growth of pollen tubes while higher concentrations inhibit growth. To test whether these effects were species specific, the effects of applied ATPyS were measured in Medicago truncatula. Medicago pollen was collected from the flowers by two different methods: a "vortex" method, in which flowers were vortexed in a pollen germination medium to release pollen, which was then separated from other flower parts, and a "dab" method in which stamen were dipped into pollen germination medium to release pollen. Collected pollen was allowed to germinate in pollen germination media (PGM) on microwell slides. ATPyS was then added and pictures were taken at an initial time point within 30 min after germination and then at a second time point about 30 to 45 min later. Using ImageJ, data on the length of the pollen tubes and on their growth rates were collected, then these data were statistically analyzed using a Student t-test. A dose-response curve of the growth rate of pollen tubes vs. [ATPyS ] was constructed. When the vortex method was used, there was no significant difference between the growth rate of the Controls and that of pollen grown in low concentrations of ATPyS. However, when the dab method was used there was a significant increase in growth rate as the ATPyS concentration increased up to 90 uM. The difference in the results yielded by the two methods could be because the vortex method releases ATP into the media during pollen isolation, desensitizing the pollen to the effects of subsequently applied nucleotides, while the dab method does not. (Supported by ASPB Summer Undergraduate Research Fellowship to N.H.).
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1 - University of Texas, Molecular Cell and Developmental Biology, 819 E 31st street, Austin, TX, 78705, United States
2 - University of Texas, Molecular Cell and Developmental Biology
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM