Auxins
Hormones are produced naturally by plants, while plant growth regulators are applied to plants by humans. Plant growth regulators may be synthetic compounds (e.g., IBA and Cycocel) that mimic naturally occurring plant hormones, or they may be natural hormones that were extracted from plant tissue (e.g., IAA). They also promote the production of other hormones and in conjunction with cytokinins, they control the growth of stems, roots, and fruits, and convert stems into flowers. Auxins were the first class of growth regulators discovered. They affect cell elongation by altering cell wall plasticity. Slide 2: Nature of Auxins The term auxin is derived from the Greek word auxein which means to grow. Compounds are generally considered auxins if they can be characterized by their ability to induce cell elongation in stems and otherwise resemble indoleacetic acid (the first auxin isolated) in physiological activity. Translocation of Auxin Auxin travels from cell to cell being taken up on one side of the cell by influx transporters in the plasma membrane and moved out on the other side by efflux transporters-called PIN proteins-where it can then be taken up by the adjacent cell. Nature of Auxins The term auxin is derived from the Greek word auxein which means to grow. Compounds are generally considered auxins if they can be characterized by their ability to induce cell elongation in stems and otherwise resemble indoleacetic acid (the first auxin isolated) in physiological activity.  Plant hormones are signal molecules produced within the plant, and occur in extremely low concentrations. A morphogen is a substance governing the pattern of tissue development, and the positions of the various specialized cell types within a tissue. In plants, growth occurs during cell division, cell elongation and cell differentiation. Those hormones make a difference in any or all these various processes in plants. Auxin, or indoleacetic acid (iaa), carries a very proficient relation to growth. Auxins are hormones involved in plant-cell elongation, apical dominance, and rooting. A well known natural auxin is indoleacetic acid, or IAA which is produced in the apical meristem of the shoot. Developing seeds produce IAA, which stimulates the development of a fleshy fruit. Cytokinins. Cytokinins promote cell division in plants. Produced in the developing shoots, roots, fruits and seeds of a plant, cytokinins are very important in the culturing of plant tissues in the laboratory. A high ratio of auxins to cytokinins in a tissue-culture medium stimulates root formation. The term ‘auxin’ is derived from the Greek word ‘auxein’ which means ‘to grow’. Compounds are generally considered auxins if they can be characterized by their ability to induce cell elongation in stems and otherwise resemble indoleacetic acid (the first auxin isolated) in physiological activity. In plants, growth occurs during cell division, cell elongation and cell differentiation. Those hormones make a difference in any or all these various processes in plants. Auxin, or indoleacetic acid (iaa), carries a very proficient relation to growth. The word hormone is derived from Greek, meaning set in motion. Plant hormones affect gene expression and transcription levels, cellular division, and growth. They are naturally produced within plants, though very similar chemicals are produced by fungi and bacteria that can also affect plant growth. Plant cells produce hormones that affect even different regions of the cell producing the hormone. Hormones are transported within the plant by utilizing four types of movements. For localized movement, cytoplasmic streaming within cells and slow diffusion of ions and molecules between cells are utilized. Auxins are a type of hormone, or growth substance, acquired from plants. Plant hormones are molecules manufactured by plants to accelerate, inhibit or modify its growth. In plants, growth occurs during cell division, cell elongation and cell differentiation. Those hormones make a difference in any or all these various processes in plants. Auxin, or indoleacetic acid (iaa), carries a very proficient relation to growth. The word hormone is derived from Greek, meaning 'set in motion.' Plant hormones affect gene expression and transcription levels, cellular division, and growth. They are naturally produced within plants, though very similar chemicals are produced by fungi and bacteria that can also effect plant growth. They also promote the production of other hormones and in conjunction with cytokinins, they control the growth of stems, roots, and fruits, and convert stems into flowers. Auxins were the first class of growth regulators discovered. They affect cell elongation by altering cell wall plasticity.
https://www.thcfarmer.com/community/threads/plant-hormones-and-growth-regulators.29938/ http://www.authorstream.com/Presentation/aSGuest7184-124916-lect2-auxin-2005-others-misc-ppt-powerpoint/ https://answers.yahoo.com/question/index?qid=20060917202717AAtzuwx http://www.innovateus.net/earth-matters/what-are-auxins http://www.biology-online.org/11/10_growth_and_plant_hormones.htm http://www.innovateus.net/earth-matters/what-are-auxins https://en.wikipedia.org/wiki/Plant_hormone http://www.innovateus.net/earth-matters/what-are-auxins https://www.thcfarmer.com/community/threads/plant-hormones-and-growth-regulators.29938/
chemicals produced in plants that are characterized by their ability to induce cell elongation and cell division in stems