Lesson 8. Understanding Plant Growth Regulators. Next Generation Science/Common Core Standard Addressed.
Understanding Plant Growth Regulators
Which grapes would you rather eat?
The ones on the left were treated with gibberellic acid to make them larger.
This trunk should be a single stem; however, the terminal bud was removed forcing it to branch.
The left side of the plant was exposed to the sun. The right side had shade and grew faster.
In tissue culture, cell division or root growth can be encouraged by adjusting hormones in the agar. If given higher levels of auxins in the agar, roots are produced. If given higher levels of cytokinins, shoots multiply.
In this experiment, two holly twigs were placed under separate jars for a week. At the same time, an apple was placed in the second jar. The ethylene given off by the apple caused the holly to lose its leaves and die.
The dormant bud on the left has a high concentration of abscisic acid. As spring nears, the acid level drops and the bud begins to develop a new shoot.