In this study, I determined the average amount of growth that occurs when coleoptiles are exposed to different amounts and concentrations of IAA. I tested the hypothesis if more auxin is given then the plant will experience a larger growth. The tips of the coleoptiles were cut and then placed in different amounts and concentrations of IAA, ranging from .1ppm to 1000.0 ppm, and set in the dark for one week. They were then pulled out of darkness and the growth of each coleoptile was recorded. Results showed that group four (decapitated coleoptile in 1.0 ppm IAA), had the largest average growth of 11.6mm, while group two (decapitated coleoptile in water), showed no growth. This study is relevant to determine the best levels of IAA for plants to grow.
Introduction.
Hormones are natural chemical messages in the body to trigger a receptor into activating a response (Utrecht, 2010). Just as animals have hormones, so do plants. Plant hormones are chemical signals that may stimulate plants to grow. Indole-3-acetic Acid (IAA) is the most common, naturally occurring form of auxin in plants (Sheldrake, 2008). Auxins, which coordinate growth and behavior processes that are essential for plant development (Christian, 2006). Auxin aids in the lengthening of the shoot in plants. Research has shown that auxin causes elongation of stem and coleoptile cells, and they do this by promoting the loosening of walls via cleavage of bonds (Rayle, 1992). In our experiment I determined the correlation between auxin hormone levels and amount of growth. I predict that if more auxin is given to the coleoptile, then the more growth the plant will experience. In the experiment we conducted tips of coleoptiles were cut and placed into petri dishes containing concentrations of IAA ranging from .1ppm to 1000ppm. The coleoptiles were then placed in darkness for one week, pulled out, and the growth of each coleoptile was recorded.
