Comparing the Growth of Rosettes Treated with giberellic Acid Versus Ordinary Plant Growth Introduction Background: Giberellic acid is a growth hormone used to stimulate cell division and cell elongation that affects leaves and stems of plants. We tested the effects it had on Rosette-Dwarf seeds by applying the giberellic acid by spraying it on the test group of plants in order that the most growth would occur. This way we made sure that the giberellic acid reached the apical meristem of the rosettes. We did this because giberellic acid mainly enhances growth at the tip of stem shoots-the apical meristem (Effects of giberellic Acid on Plants). Types of Hormones: There are 5 different types of plant hormones: Auxins, Gibberellins, Ethylene, Cytokinins and Abscisic Acid. Auxins are hormones involved in plant cell elongation, apical dominance and rooting. Gibberellins primarily stimulate elongation growth. Ethylene is unique because it is a gas at room temperature and is primarily responsible for the ripening of fruits. Cytokinins promote cell division in plants and are produced in the developing shoots, roots, fruits and seeds of plant. Abscisic Acid or ABA generally inhibits other hormones and helps bring dormancy to buds and seeds (Growth and Plant Hormones - Plant Biology). Hypothesis: The rosettes mustard seedlings will grow taller after being treated with giberellic acid than those without treatment because giberellic acid promotes cell division and cell elongation. Materials and Methods Site of investigation: The rosettes were treated every Monday, Wednesday, Friday for 3 weeks. Half of the rosettes were treated with giberellic acid by an eyedropper. Facts about rosettes: Rosette-Dwarf plants compared to wild mustard seeds produce themselves 4-10 times less giberellic acid. The lack of GA prevents the stem from elongating so that the leaves are near the soil and the plant appears dwarfed (Rosette-Dwarf). Equipment used: Styrofoam containers Soil giberellic acid Spray bottle Rosette dwarf seeds Fertilizer Soil Ruler Sticks for support Quantity of treatment: 2 full sprays, 3 inches from the top of the plant Statistical procedures: Through Microsoft Excel, the data was organized in charts. We performed a t-test to find out if there was a significant difference in height of rosettes treated with giberellic Acid verses plants without treatment. Procedure: 1.Put water transfer diamond into Styrofoam containers 2.Fill Styrofoam containers halfway full of soil 3.Add 2 fertilizer beads 4.Fill container almost to top with soil 5.Add 1 rosette seed 6.Cover with soil 7.Using eyedropper, add soapy water to each container 8.Put on top of water source with felt cloth (helps water the plant) 9.Put in greenhouse and wait for germination 10.Every Monday, Wednesday, Friday, spray treatment group with giberellic acid (2 full sprays 3 inches away from top of plant) 11.Continue to water the plants when necessary 12.Record height of plant using ruler in millimeters 13.Do this until 9 measurements have been taken Results: Data and Analysis According to the t-test the p-value was According to the chart “below: 2 out of 32 plants never germinated. 3 out of 32 plants died during the experiment. The average plant height of rosettes that were treated were higher than the non treated rosettes The only problem we encountered were that a few plants had yellow/brown spots on them towards the end of the experiment. The overall heath of the plants was good. They were green, strong, tall, and healthy. According to the graph below (rosette treated vs. untreated) the treated plants grew taller than the untreated plants Conclusion: In conclusion, there was a difference in height from the plants treated with giberellic acid compared to the non treated plants. However, our hypothesis is proved false because according to the t- test there is no significant difference between the height of rosettes treated with giberellic acid vs. non treated. Our findings agree to a certain extent with similar experiments, however most of the experiments had more conclusive results. One in particular determined that there is a significant difference in height of rosettes treated with GA versus non treated (giberellic Acid). We think that the reason we did not get significant results is because there might have been a flaw in our application of the GA. Also, if we had had a greater number of plants, we might have limited the number of genetic variation, causing our results to be more significant. Our new understanding is that GA does increase growth in plants, but if sprayed on to the whole plant, there is not a significant difference between untreated plants and treated plants. If we were to have a next step in our study, we would vary the concentration of GA on the plants and test a larger number of plants to factor in for genetic variation (A Gibberellin-Deficient Brassica Mutant— rosette). Jordan Florian, John Gavin, Hannah Schroder, Sophia Storer St Dev=23 St Dev=13 Works Cited A Gibberellin-Deficient Brassica Mutant—rosette. (n.d.). Retrieved May 11, mmm2014, from mmmhttp:// Effects of giberellic Acid on Plants. (n.d.). GardenGuides. Retrieved May 13, mmm2014, from mmmacid-plants.html giberellic Acid. (n.d.).. Retrieved May 13, 2014, from mmmhttp:// Growth and Plant Hormones - Plant Biology. (n.d.). Growth and Plant mmmHormones.Retrieved May 13, 2014, from mmmonline.org/11/10_growth_and_plant_hormones.htm Rosette-Dwarf. (n.d.). Wisconsin Fast Plants. Retrieved May 12, 2014, from mmmhttp:// Rosette Mustard Seed Growth over a Three Week Period