Leucoplast
Leucoplasts are a category of
plastid and as such are
organelles found in
plant cells. They are non-pigmented, in contrast to other plastids such as the
chloroplast and the
chromoplast.
Lacking
pigments, leucoplasts are not green, so they are predictably located in
roots and non-photosynthetic tissues of plants. They may become specialized for bulk storage of
starch,
lipid or
protein and are then known as
amyloplasts,
elaioplasts, or
proteinoplasts. However, in many cell types, leucoplasts do not have a major storage function and are present to provide a wide range of essential biosynthetic functions, including the synthesis of fatty acids, many amino acids, and tetrapyrrole compounds such as haem. In general, leucoplasts are much smaller than
chloroplasts and have a variable morphology, often described as amoeboid. Extensive networks of
stromules interconnecting leucoplasts have been observed in epidermal cells of
roots,
hypocotyls and
petals, and in
callus and suspension culture cells of tobacco. In some cell types at certain stages of development, leucoplasts are clustered around the
nucleus with stromules extending to the cell periphery, as observed for proplastids in the root meristem.
*
Chloroplast and
Etioplast*
Chromoplast*
Amyloplast*
Elaioplast*
Stromules: a characteristic cell-specific feature of plastid morphology. : A good review on
stromules (unfortunately access is restricted to suscribers)
