Searching for Components of the Gravity Sensing System in Plants

Students: Manga Bauer ’23, Regina Campbell ’22, Mo Cartnal ’24, Ale Coronel-Zegarra ’22, Marquise Downing ’22, Abby Doza ’23, Ross Eggleston ’22, Catie Hyatt ’22, Reagan Jennings ’23, Carly Schafer ’23, Myles Steed ’23, Sai Suresh Kannan ’24, Athena Vakaleris ’22, and Makaila Weir ’21
Research Mentor: Chris Wolverton (OWU Department of Biological Sciences)

By identifying genes that are involved in plant gravity response, we can better understand the processes that allow plants to grow properly, and further NASA’s mission to successfully cultivate plants in space. In prior research, a list of 124 genes were identified as possibly being key players. We have chosen 25 of those genes to test this summer in order to determine which of them are involved in responses to gravity in Arabidopsis plants (Thale Cress.) In the future, our results could be applied to successfully grow food crops in lower- and zero-gravity environments.

Gravity is the predominant influence on plant growth and subsequent plant architecture. It has been discovered that a plant’s primary response to gravity comes from the sedimentation of starch-filled structures called amyloplasts. Researchers have determined that mutant Arabidopsis plants without amyloplasts retain a significant response to gravity and have sought to identify additional molecular components for their contributions to the gravity response pathway. Over the past several years, research has led to the isolation of 124 Arabidopsis genes with the potential to affect plant response to gravity. Current research adds on to previous work where 30 genes were experimented on to isolate statistically significant differences between mutants and wild type plants. Gravitropism response in 25 confirmed Arabidopsis mutant genes were further tested using free rotation, continuous rotation and phototropism experimental analyses. Results of mutant comparative analysis are incomplete.

A list of 124 genes was previously determined to be significant in the plant gravity response pathway with regards to Arabidopsis thaliana. 25 genes from the list of 124 previously identified genes were chosen for analysis. Each mutant was confirmed to be homozygous through PCR and gel electrophoresis. Each confirmed mutant was grown to the seedling stage and ran through a series of tests. The first test included attaching five seedlings to a motor that turned them exactly 90 degrees. The plants were grown at 90 degrees for 200 minutes, and a photograph was taken every 10 minutes. Angle measurements were recorded at determined intervals. The second test included the rotation of five seedlings 15 degrees per hour for 200 minutes. Photographs were taken every 10 minutes, and angle measurements were recorded at specific intervals. The third test included growing 20 seedlings vertically with a blue strip light shining on them at 90 degrees. The plants remained with the blue light at 90 degrees for 20-24 hours, and an image was taken of them at the end of the test.

The results of this research have not yet been determined.