"Like clockwork, at a certain temperature the germination of the seeds occurs under microgravity conditions," he said. "We're treating a similar batch of seeds that has been put in an orbital environmental simulation chamber on the ground with a real-time linkage to the seed container aboard Columbia.
"What we're trying to do is to treat these two batches of seedlings the same, except that one will be exposed to one G of gravity and the other to microgravity."
Reddy shows a certain yen to fly, at least for scientific purposes, because metabolic changes will start on the ground, he said. However, they shouldn't affect the experiment.
He adds, somewhat wistfully, "the ideal thing would be to do all this in space, but it is not possible."
The team has had a tough schedule after the mission was delayed twice from its scheduled July 20 launch. For all three planned launches, they began seed preparation about 1:30 a.m. the day before.
"NASA advised us to be prepared for up to five "scrubs," or cancellations, of the mission, so each day until launch we'd have to prepare a batch of seedlings ready to place on the shuttle," Safadi-Chamberlain said.
The results of the experiment should be novel and worth the effort, however. A plant physiologist, Reddy has long been interested in how plants transmit signals at the molecular level.
"Nobody really knows how roots sense gravity, but there are papers in the literature suggesting that calcium is involved," he said. "Recently, mutants with altered or no gravitropic response have been isolated, suggesting that there are specific genes involved in gravity signal transduction."
"That makes me think that in microgravity we might be able to learn about this whole mechanism by identifying the genes regulated by gravity."
"We
'"/>
Contact: David Weymiller
dweymiller@vines.colostate.edu
970-491-6851
Colorado State University
23-Jul-1999