Date of Award

2020

Document Type

Thesis

Degree Name

Bachelors

Department

Natural Sciences

First Advisor

Clore, Amy

Area of Concentration

Biology

Abstract

The International Space Station (ISS) is a research station where astronauts live and conduct cutting edge space research. While many think the ISS exists in a state of “zero-g”, the station and its inhabitants are actually exposed to “microgravity”, which is broadly defined as, “less than 1 g.” Gravitropism is defined as the growth of a plant in response to the pull of gravity. There is evidence that the standard gravitropic pathway is altered in plants exposed to microgravity. A 3D clinostat is a device consisting of two frames with motors that rotate in perpendicular directions at random, disparate rates. Past researchers have shown rotation at a rate between 2 and 4 rpm during a 15-60 second time interval to be an acceptable microgravity simulation. Under these parameters,​ the sum of the perceived gravity vectors nets to near zero ​with a minimum amount of disturbance due to centrifugal force. To characterize the induced abiotic stress response Triticum aestivum ​ L. (wheat) exhibits under microgravity conditions, dozens of genes implicated in gravitropism and microgravity studies of the model plants ​Arabidopsis thaliana ​ and ​Zea mays ​ L. were analyzed and compared to similar genes in ​T. aestivum ​ . Primers for the genes of interest and housekeeping genes were carefully designed and selected based on specificity. The primer pairs were further narrowed down based on the slope of the standard curve and dissociation curve profile, and then the relative quantitation of the target genes in response to 3D clinorotation was analyzed via quantitative polymerase chain reaction (qPCR). It was found that in the clinostat-treated plants, mRNA corresponding to cytoplasmic aconitase (cACO) was downregulated 35%, and RNA from a J-domain protein was downregulated 30% compared to the upright control plants.

Download

Share

COinS