They are usually found in non-photosynthetic tissues such as endosperm, tubers, roots, bulbs, and seeds. They specialize in storing starch, protein, and lipids in plants. Leucoplasts may also perform biosynthetic functions such as synthesizing fatty acids, amino acids, and various other compounds.
Structure: What does it Look like
Types with Functions
Difference between Leucoplast, Chloroplast, and Chromoplast
In epidermal cells of roots, hypocotyls, and petals, leucoplasts remain interconnected by extensive networks of stromules (stroma-filled tubules). During the development of certain cell types, leucoplasts cluster around the nucleus with stromules extending to the cell periphery.
1) Amyloplast
Amyloplasts convert glucose to starch and store it in tubers, seeds, stems, and fruit. They also synthesize transitory starch for photosynthetic parts. After synthesis, the starch is stored temporarily in chloroplasts and broken down at night to release energy when photosynthesis does not occur. Stratoliths are special amyloplasts that involve the sensing of gravity in plants. They are exclusively found in plant roots. Here, the stored starch granules are denser than the cytoplasm and therefore are affected by gravity. This induces the growth of the root in a downward direction.
2) Elaioplast
These leucoplasts, also called oleosomes, synthesize fatty acids and store lipids in lipid-filled microcompartments called plastoglobuli. They play a key role in the development of pollen grains.
3) Proteinoplast
Also known as aleuroplasts, these leucoplasts store protein and are commonly found in seeds.
