Chromoplast

(redirected from chromoplasts)
Also found in: Dictionary, Thesaurus, Medical.

chromoplast

[′krō·mō‚plast]
(cell and molecular biology)
Any colored cell plastid, excluding chloroplasts.

Chromoplast

 

a pigmented intracellular organelle of plant cells; a type of plastid. Chromoplasts may be spherical, spindle-shaped, sickle-shaped, or irregularly polygonal. Their orange, yellow, or brownish coloring is caused principally by carotenoids. Chromoplasts are usually formed from green plastids—chloroplasts—as green chlorophyll pigments are destroyed in the process of the ripening of the fruits of certain plants, such as mountain ash, lily of the valley, and persimmon, and during the autumn yellowing of leaves. At this stage the protein-lipid membrane of the chloroplast system decomposes. The protein flows out of the plastids, while the lipid remains inside, dissolving the carotenoids, which color the plastids orange and yellow. In some instances the chromoplasts are formed from colorless plastids—leukoplasts—for example, in carrot roots.

REFERENCES

See references under PLASTIDS.
References in periodicals archive ?
Quinone compounds are able to replace molecular oxygen as terminal electron acceptor in phytoene desaturation in chromoplasts of Narcissus pseudonarcissus L.
In Lycopersicon peruvianum, another anemophilous species, the pathway is the same but without the chromoplast stage.
carotenoids pigments: Plant cell pigments: red, orange, and yellow lipid soluble pigments found embedded in the membrane of chloroplast and chromoplast.
In the fruits and vegetables in which it is found, lycopene is naturally packaged in tiny structures called chromoplasts.
The carotenoids that impart yellow through orange colors are found within other small cell packets called chromoplasts.