Graduate Student North Carolina State University Raleigh, North Carolina
Body of Abstract: For future spaceflight, it is important to understand plant growth and response to altered gravity. In microgravity, fluid dynamics is disrupted and biochemical processes that depend on diffusion may be disrupted. The circadian clock regulates the plant’s biochemical and molecular activities so they are coordinated with the 24h daily cycle by coordinating external environmental queues with internal processes. The circadian clock is a tightly connected molecular network dependent on precise diffusion and kinetics for its function. Therefore, we wanted to ask the question: does reduced gravity affect the circadian clock?
To examine the effect of microgravity on the circadian clock, we utilized the Random Positioning Machine (RPM) to simulate microgravity. A time course was carried out utilizing the RPM to harvest samples every 2 hours for 48 hours, allowing the observation of the transcriptional response of core clock genes to simulated microgravity. Two complete replicates for the time course were harvested.
RNA isolated from the shoot tissue of each time point was used for transcriptional analysis to observe the effect of microgravity on the core circadian clock genes as well as alterations of downstream clock-related targets. RNA-seq analysis of the time course by mapping to the transcriptome will allow for a more accurate quantification of transcript abundance throughout the time course. This time course is the first comprehensive observation of the molecular effects of the plant response to the abiotic stress of simulated microgravity, and will be useful for understanding the how the effects of microgravity on the circadian clock will impact future long term space travel.