Infographic Template Galleries

Created with Fabric.js 1.4.5 Auxin Phyllotaxies Phyllotaxies are how leaves are arranged on the stem. Peaks/ larger concentrations of auxin determine the site of leaf formation. This creates different phyllotaxies. Low levels of auxin in branches causes new branches to develop below branches that have low auxin levels. Branching Patterns Basic Information Auxin is a plant hormone that is primarily located in the shoot tips and developing leaves of plants. Auxin is transported through the process of polar transport. Auxin's main purpose is the elongation of coleoptiles. The process of cell elongation can be further understood by the Acid Growth Hypothesis. Auxin plays a crucial role in pattern formations such as branching patterns, phyllotaxies, and veins. Auxin also has three main practical uses as an herbicide, to cause root growth from surfaces of cut leaves, and causing fruit growth. Auxin will also work with other hormones in Apical Dominance Control, Fruit Growth, Cellular divison, and differentiation, and Leaf Abscission. Polar Transport Double click to change text Polar transport is best described as auxin moving from the shoot tips down to the roots. Auxin will only move through xylem cells in the stem. Acid Growth Hypothesis Proton pumps in the cell wall will create an acidic environment in the cell wall by pumping hydrogen ions into the cell wall. The activation of the proton pumps is caused by auxin. The acidic environment causes expansin enzymes to break cellulose cross links, thus making the cell wall looser, allowing for the cell to uptake water and expand to react to the hypotonic environment. This uptake in water creates turgor pressure and elongates the cell. A lack of auxin transport causes the main veins to have little organization, a loarge number of secondary veins, and the vascular cells next to the leaf margin to be irreguarly shaped. This layout of veins does not have vascular continuity. Veins Herbicide Use Auxins are effective at killing eudicots, due to eudicots inability to inacticate synthetic auxins. As a result eudicots will die from hormonal overdose, while the monocots are still alive. Root Growth Use Double click to change text The natural auxin called indolebutyric acid (IBA) causes lateral roots to form off of a detached stem or leaf. This creates a new functioning plant. Fruit Growth Use Synthetic auxins can cause fruit to growth. THis is particularly helpful in greenhouse tomatos where fruit growth and seed production is usually reduced. Spraying synthetic auxins allows for tomatos to be grown commercially Hormone Collaboration Apical Dominance Control Apical Dominance Control is the apical bud's ability to suppress axillary buds from forming and developing. Auxins work with cytokinins and strigolactones in apical dominance control. The direct inhibition hypothesis stated that a ratio of auxins to cytokinins controlled bud inhibition. If there was a greater amount of auxins in the system, axillary buds would not grow, while lateral branches would. If there was a greater amount of cytokinins in the plant, axillary buds would grow, while lateral branches would not. In addition, a plant would become bushier if the apical bud, which is the primary source of auxin, was cut. The plant would develop normally if auxin was put on the cut base of the apical bud. However, the discovery of strigolactones complicated the direct inhibition hypothesis, for strigolactones will be synthesized and repress bud growth if auxin flow down the shoot is uninterrupted. Fruit Growth Auxins and Giberellins are both very important for fruit growth. Auxins control the growth of side buds and the retention of the fruit on the plant. While gibberellins control the growth of the fruit size. Larger varieties of Thompson seedless grapes are usually sprayed with gibberellins. Leaf Abscission Leaf Abscission is the loss of leaves during climatic seasonal periods. Abscission usually occurs when there is limited availability of water to the roots of a plant. Abscission is caused by a ratio of auxin and the gas Ethylene. Leaves produce less auxin as they age, leaving them more reactive to ethylene. This means that the leaves will naturally abscess past a certain age. Cytokinins Basic Information Cytokinins were first discovered in investigations aimed at finding additives that would stimulate growth. Research proved that modified forms of adenine stimulated growth and were named cytokinins due to their ability to promote cellular division. Cytokinins are produced in roots and are transported through the plant in the xylem. A common natural cytokinin is zeatin, first found in corn. Cytokinins prevent the aging of plant organs. In collaboration with other plant hormones, cytokinins control apical dominance and control cellular division, and cellular differentiation. Anti-Aging Use Cytokinins are used for their anti aging effects they project onto several plant organs. They slow the aging process by i=stopping protein breakdown, promoting protein and Ryna synthesis, and transporting nutrients from the surrounding tissues to the targeted organ. Cytokinins slow apoptosis, which is a planned death of many plant cells. Leaves will also stay green for a longer period of time if they are dipped in a solution containing cytokinins. Hormone Collaboration Apical Dominance Control is the apical bud's ability to suppress axillary buds from forming and developing. Auxins work with cytokinins and strigolactones in apical dominance control. The direct inhibition hypothesis stated that a ratio of auxins to cytokinins controlled bud inhibition. If there was a greater amount of auxins in the system, axillary buds would not grow, while lateral branches would. If there was a greater amount of cytokinins in the plant, axillary buds would grow, while lateral branches would not. In addition, plants that had larger amounts of cytokinins were usually thicker and bushier than a plant with normal cytokinin levels. However, the discovery of strigolactones complicated the direct inhibition hypothesis, for strigolactones will be synthesized and repress bud growth if auxin flow down the shoot is uninterrupted. Apical Dominance Control Cell Differentiation and Division See Cytokinins hormone collaboration bubble Cell Differentiation and Division Both Cytokinins and Auxins work with each other in cellular division and differentiation. If only Auxins are present in growing tissues, the cells will become very large, but will not divide, and stay as large cells. The addition if Cytokinins with auxins causes the cells to both grow and divide. If there is only cytokinins and no auxins, the cells will neither grow nor divide. The ratio between cytokinins and auxins cause the cells to differentiate. A callus is a group of cells that are undifferentiated from one another. This occurs when the hormones are at a very specific level, causing the cells to grow, but not differentiate. Shoots will form if the cytokinin levels increase; and roots will form if auxin levels increase. Fun Fact: Xylem Xylem, which is pertinent in the transport of many steroids such as cytokinins and auxin, is one of only two vascular transport tissues in plants. The other such tissue is called phloem. Xylem transports water and nutrients from the roots upwards. While phloem transports sugars and nutrients from the leaves downward Both cytokinins and auxins work with each other in cellular division and differentiation. If onlt auxins are present in growing tissues, the cells will become very large, but will not divide, and stay as large cells, The addition of cytokinins with auxins causes the cells to both grow and divide. If there is only cytokinins and no auxins, the cells will neither grow nor divide. The ration between cytokinins and auxins cause the cells to differentiate. A callus is a group of cells that are undifferentiated from eachother. this occurs when the hormones are at a very specific level, causing the cells to grow, but not differentiate. Shoots will for if the cytokinin levels increase; and roots will form if auxin levels increase.
Create Your Free Infographic!