Chromoplast

Chromoplasts are plastids responsible for pigment synthesis and storage. They, like all other plastids (including chloroplasts and leucoplasts), are organelles found in specific photosynthetic eukaryotic species.

Chromoplasts in the traditional sense are the interior found in coloured organs of plants such as fruit and floral petals, to which they give their distinctive colors. This is always associated with a massive increase in the accumulation of carotenoid pigments. The conversion of chloroplasts to chromoplasts in ripening is a classic example.

Chromoplasts synthesize and store pigments such as orange carotene, yellow xanthophylls, and various other red pigments; as such, their color varies depending on what pigment they contain. The probable main evolutionary role of chromoplasts is to act as an attractant for pollinating animals (e.g., insects) or for seed dispersal via the eating of colored fruits. They allow the accumulation of large quantities of water-insoluble compounds in otherwise watery parts of plants. In chloroplasts, some carotenoids are also used as accessory pigments in photosynthesis, where they act to increase the efficiency of chlorophyll in harvesting light energy. When leaves change color in autumn, it is due to the loss of green chlorophyll unmasking these carotenoids that are already present in the leaf. In this case, relatively little new carotenoids are produced. Therefore, the change in plastid pigments associated with leaf senescence is somewhat different from the active conversion to chromoplasts observed in fruit and flowers.

The term "chromoplast" is occasionally utilized to include any plastid that has pigment, mostly to emphasize the contrast with the various types of leucoplasts, which are those plastids that have no pigments. In this sense, chloroplasts are a specific type of chromoplast. Still, "chromoplast" is more often used to denote those plastids with pigments other than chlorophyll.

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Look at other dictionaries:

  • chromoplast — [krō′mə plast΄] n. [ CHROMO + PLAST] a yellowish to reddish plastid containing carotenoids and found in the cytoplasm of many plant cells: see CHLOROPLAST …   English World dictionary

  • chromoplast — noun Etymology: International Scientific Vocabulary Date: 1885 a colored plastid usually containing red or yellow pigment (as carotene) …   New Collegiate Dictionary

  • Chromoplast — Chromoplasten (von altgriechisch χρῶμα chroma „Farbe“ und altgriechisch πλαστός plastós „geformt“) sind Plastiden, die Xanthophylle oder Carotine enthalten und die Pflanzenteile, in denen sie vorkommen, gelb, orange oder rot (anstatt… …   Deutsch Wikipedia

  • chromoplast — Plant chromatophore filled with red/orange or yellow carotenoid pigment. Responsible for colour of carrot and of many petals …   Dictionary of molecular biology

  • chromoplast — /kroh meuh plast /, n. Bot. a plastid containing coloring matter other than chlorophyll. [1880 85; CHROMO + PLAST] * * * …   Universalium

  • chromoplast — noun Any plastid in which a pigment is synthesized or stored …   Wiktionary

  • chromoplast — A plastid filled with carotenoid pigments. * * * chro·mo·plast krō mə .plast n a colored plastid usu. containing red or yellow pigment (as carotene) * * * chro·mo·plast (kroґmo plast) chromoplastid …   Medical dictionary

  • Chromoplast — Chro|mo|plạst 〈[kro ] m. 16〉 Farbstoffträger verschiedener Pflanzenzellen, der die Gelb bis Rotfärbung zahlreicher Blüten u. Früchte bewirkt [<grch. chroma „Farbe“ + plastes „Bildner“] * * * Chro|mo|plạst, der; en, en <meist Pl.> [zu… …   Universal-Lexikon

  • Chromoplast — Chro|mo|plạst 〈[kro ] m.; Gen.: en, Pl.: en〉 Farbstoffträger verschiedener Pflanzenzellen, der die Gelb bis Rotfärbung zahlreicher Blüten u. Früchte bewirkt [Etym.: <Chromo… + grch. plastes »Bildner«] …   Lexikalische Deutsches Wörterbuch

  • Chromoplast — Chro|mo|plast* der; en, en (meist Plur.) <zu gr. plastós »gebildet, geformt«> gelber od. roter kugeliger Farbstoffträger bestimmter Pflanzenzellen, der die Färbung der Blüten od. Früchte bestimmt …   Das große Fremdwörterbuch

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