The Leucoplast is a type of plastid. Plastids are storage organelles found in plant cells, that include chromoplasts (they hold the colored pigments for organisms such as flowers) and chloroplasts (which hold the green pigment found in plant cells). Leucoplasts (the third type of plastid) do not have any pigment and therefore appear clear under a microscope. They are responsible for storing food related items for the plant, like lipids, proteins, and starches. Additionally, leucoplasts can be responsible for synthesizing amino acids and fatty acids.
|
In fact, there are three types of leucoplasts: amyloplasts, elaioplasts, and proteinoplasts. They store starches, lipids, and proteins, respectively. The amyloplast can store starches and convert those starches into sugar for energy, when the plant requires it. Additionally, it can turn into a chloroplast. (Ever notice that some of your potato chips are green? That green pigment comes from a converted amyloplast.) Little is known about the elaioplast and the proteinoplast. Other than transport of the energy source into/out of the organelle, via the ribosome, the leucoplast has little to no interaction with other parts of the cell, as it simply serves as a storage.
Stratoliths are special amyloplasts that involve the sensing of gravity in plants. These amyloplasts, found in the root of a plant, are denser than the cytoplasm and therefore are affected by gravity as they are pulled downward. This downward pull, or sedimentation, activates tiny amounts of stress onto specailized carriers and then a hormone makes the roots grow the way they do. This is why plants' roots grow downward (mostly), and not sideways or upwards.
Stratoliths are special amyloplasts that involve the sensing of gravity in plants. These amyloplasts, found in the root of a plant, are denser than the cytoplasm and therefore are affected by gravity as they are pulled downward. This downward pull, or sedimentation, activates tiny amounts of stress onto specailized carriers and then a hormone makes the roots grow the way they do. This is why plants' roots grow downward (mostly), and not sideways or upwards.