Student Research Projects

Root-bound anonymous: Does being root-bound affect the recovery of bryophyllum diagremontianum plants?

Student Elizabeth Allen ’15 (Biology)
Faculty Mentor(s)
Department Biology
Course Biology 489: Research Methods in the Natural Sciences

Abstract

Little research has been done to examine the recovery of plants to being root-bound. This research sought to compare aspects of growth between root-bound plants and those recovering from being root-bound in Bryophyllum diagremontianum plants. These included measuring levels of a key phytohormone auxin, as well as cell division rates using the mitotic index, the ratio of meristematic cells undergoing mitosis to the total number of meristematic cells within the view of a light microscope. Auxins comprise a large group of plant hormones, including the most common endogenous form indole-3-acetic acid (IAA), that have been shown to function in plant dev elopement. Therefore, the hypothesis was that IAA levels in root-bound B. diagremontianum plants would be depleted, while recovering individuals would have elevated IAA levels in comparison. IAA levels were to be compared by extracting and purifying total auxin via liquid-liquid extractions and purified using C-17 cartridges to ultimately be quantified using a selected bioassay. Three different bioassays were assessed, including an Avena curvature test, GUS assay, and GUS activity hybrid assay, using pure IAA to obtain a dose-response curve. While a successful curve was found with the GUS activity hybrid assay, difficulties arose in developing the extraction protocol. Furthermore, imaging B. diagremontianum chromosomes was not possible, as compared to control plants using multiple chromosome stains. Future experiments should focus identifying a more appropriate plant with chromosomes amenable to quantifying the mitotic index, as well as the refinement of both the extraction protocol and the GUS activity hybrid assay.

Grants

Recipient of a Virginia Wesleyan Undergraduate Research Grant for Research, 2015.