The Effects of Red Light on Blue-Light Phototropism in Arabidopsis Thaliana

Neel, Alison Michelle (2016) The Effects of Red Light on Blue-Light Phototropism in Arabidopsis Thaliana. Undergraduate thesis, under the direction of John Z. Kiss from Biology, The University of Mississippi.


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Red and blue light pathways interact with one another to guide the phototropic growth and development of seedlings. Both roots and hypocotyls experience phototropism. This study aims to describe the effects of red light on blue-light phototropism and to examine the relationship between red and blue light pathways. Two wild-type ecotypes of Arabidopsis thaliana, germinated either under white light or in darkness, were exposed to different red and blue light conditions and used to examine these relationships. Red light exposure preceding growth under solely blue light was shown to have an inhibitory effect on root lengths, regardless of ecotype or etiolation. Surprisingly, red light did not produce significant phototropistic curvature in roots of either ecotype. The remainder of the results illustrated the fact that different ecotypes exhibit different phototropistic responses to light treatments and etiolation. Seedlings did not uniformly respond to constant red and blue light in the same manner as they responded to pretreatment by red light. In different circumstances, simultaneous red and blue light led to results statistically identical to blue light’s results, red pretreatment’s results, or an intermediate between the two. Our results both highlight the importance of testing multiple ecotypes within a species and reveal interesting trends in the relationship between red and blue light pathways. Red and blue light pathways interact, but different Arabidopsis ecotypes respond to each light treatment and germination condition differently, and have differing capacities to prioritize one pathway over the other when both are available.

Item Type: Thesis (Undergraduate)
Creators: Neel, Alison Michelle
Student's Degree Program(s): B.A. in Biology
Thesis Advisor: John Z. Kiss
Thesis Advisor's Department: Biology
Institution: The University of Mississippi
Subjects: Q Science > Q Science (General)
Q Science > QK Botany
Depositing User: Alison Neel
Date Deposited: 03 Jun 2016 19:23
Last Modified: 03 Jun 2016 19:23

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