Give an example of a plant hormone that promotes growth

(i)Auxin • Auxin is an example of a plant hormone that promotes the growth of the plant. • Auxins promote stem elongation and inhibit the growth of lateral buds (maintains apical dominance). • They are produced in the stem, buds, and root tips. • Auxin moves to the darker side of the plant, causing the cells to grow larger than the corresponding cells on the lighter side of the plant. (ii)Abscisic Acid • Abscisic Acid is an example of a plant hormone that inhibits the growth of the plant. • It is a growth-inhibiting hormone. • ABAs act as an antagonist to GAs. • It inhibits plant metabolism and regulates abscission and dormancy.

Hint: Growth hormones are defined as organic substances which are synthesized in minute quantities in one part of the plant body and transported to another part where they influence specific physiological processes. A group of plant hormones including auxins, gibberellins, cytokinins, ethylene, and abscisic acids is presently known to regulate growth. Complete answer: Plant growth hormones: 1. Auxin includes all chemical substances which promote the growth of the stem or coleoptiles section. Physiological effects of auxins -Cell elongation and longitudinal growth, cell division in the cambium, cell division, and tissue culture, root growth and root initiation, apical dominance, prevention of abscission layer, parthenocarpy. They are also used as herbicides. 2. Gibberlines are the plant growth hormones that enhance the longitudinal growth of stem when applied to intact plants. The presence of meristematic cells is necessary for the elongation growth caused by them. Physiological effects of gibberellins- elongation of the stem, a reversal of dwarfism, bolting and flowering, substituting the cold treatments, cell division in the cambium, etc 3. Cytokinins are plant growth substances that act primarily on cell division and have little or no effect on extension growth. Physiological effects of cytokinins – cell division, cell enlargement, initiation of infrasicular cambium, morphogenesis, counteraction of apical dominance, breaking of dormancy, delay of senescence, accumulation...

Use of plant hormones There are many types of plant hormones . They are used in agriculture and horticulture to have a specific effect. Auxins were the first class of plant hormones to be discovered. Their main function is to help plants grow and auxin stimulates plant cells to elongate . The apical meristem of a plant is one of the main places where auxin is produced. The apical meristem is also the location that all other parts of a plant grow from - the stem, leaves, and flowers. Auxins are one specific group of hormones that are used: • as weed killers • as rooting powders Weed killers Selective weed killers kill some plants, but not others. This can be useful for getting rid of dandelions in a lawn without killing the grass. The selective weed killer contains a growth hormone that causes the weeds to grow too quickly and die. Because the weeds have broader leaves, the weed killer is absorbed in larger quantities by the weeds than it is by the grass. Selective weed killers can reduce biodiversity within treated areas due to specific plants being killed. Rooting powder contains plant hormones to promote growth. Plant cuttings can be dipped in hormone rooting powder before planting. Synthetic plant hormones are used to control plant growth. For example, rooting powder contains growth hormones that make stem cuttings develop roots quickly. Other plant hormones Gibberellins are a group of plant hormones responsible for growth and development. They are important for initiat...

Hint: Growth hormones are defined as organic substances which are synthesized in minute quantities in one part of the plant body and transported to another part where they influence specific physiological processes. A group of plant hormones including auxins, gibberellins, cytokinins, ethylene, and abscisic acids is presently known to regulate growth. Complete answer: Plant growth hormones: 1. Auxin includes all chemical substances which promote the growth of the stem or coleoptiles section. Physiological effects of auxins -Cell elongation and longitudinal growth, cell division in the cambium, cell division, and tissue culture, root growth and root initiation, apical dominance, prevention of abscission layer, parthenocarpy. They are also used as herbicides. 2. Gibberlines are the plant growth hormones that enhance the longitudinal growth of stem when applied to intact plants. The presence of meristematic cells is necessary for the elongation growth caused by them. Physiological effects of gibberellins- elongation of the stem, a reversal of dwarfism, bolting and flowering, substituting the cold treatments, cell division in the cambium, etc 3. Cytokinins are plant growth substances that act primarily on cell division and have little or no effect on extension growth. Physiological effects of cytokinins – cell division, cell enlargement, initiation of infrasicular cambium, morphogenesis, counteraction of apical dominance, breaking of dormancy, delay of senescence, accumulation...

Use of plant hormones There are many types of plant hormones . They are used in agriculture and horticulture to have a specific effect. Auxins were the first class of plant hormones to be discovered. Their main function is to help plants grow and auxin stimulates plant cells to elongate . The apical meristem of a plant is one of the main places where auxin is produced. The apical meristem is also the location that all other parts of a plant grow from - the stem, leaves, and flowers. Auxins are one specific group of hormones that are used: • as weed killers • as rooting powders Weed killers Selective weed killers kill some plants, but not others. This can be useful for getting rid of dandelions in a lawn without killing the grass. The selective weed killer contains a growth hormone that causes the weeds to grow too quickly and die. Because the weeds have broader leaves, the weed killer is absorbed in larger quantities by the weeds than it is by the grass. Selective weed killers can reduce biodiversity within treated areas due to specific plants being killed. Rooting powder contains plant hormones to promote growth. Plant cuttings can be dipped in hormone rooting powder before planting. Synthetic plant hormones are used to control plant growth. For example, rooting powder contains growth hormones that make stem cuttings develop roots quickly. Other plant hormones Gibberellins are a group of plant hormones responsible for growth and development. They are important for initiat...

(i)Auxin • Auxin is an example of a plant hormone that promotes the growth of the plant. • Auxins promote stem elongation and inhibit the growth of lateral buds (maintains apical dominance). • They are produced in the stem, buds, and root tips. • Auxin moves to the darker side of the plant, causing the cells to grow larger than the corresponding cells on the lighter side of the plant. (ii)Abscisic Acid • Abscisic Acid is an example of a plant hormone that inhibits the growth of the plant. • It is a growth-inhibiting hormone. • ABAs act as an antagonist to GAs. • It inhibits plant metabolism and regulates abscission and dormancy.