DNA polymerase activity of tomato fruit chromoplasts

FEBS Letters

Carrillo, Nestor¹  Serra, Esteban C.¹ 

[1] Departamento de Ciencias Biològicas, Area Biologia Molecular, Facultad de Ciencias Bioquimicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531 (2000) Rosario, Argentina

关键词: DNA polymerase;    Chromoplast;    Plastid gene expression;    Fruit ripening;    Tomato;    Lycopersicon escalentum;    cr;    chromoplast;    cp;    chloroplast;    pt;    plastid;    araCTP;    cytosine β-D-arabinofuranoside 5′-triphosphate;    bp;    base pairs;    NEM;    N-ethylmaleimide;    Tris;    tris (hydroxymethyl)aminometane;    MES;    2-(N-morpholino) ethanosulfonic acid;    MOPS;    3-(N-morfolino)propanesulfonic acid;   

DOI  :  10.1016/0014-5793(90)81449-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

DNA polymerase activity was measured in chromoplasts of ripening tomato fruits. Plastids isolated from young leaves or mature red fruits showed similar DNA polymerase activities. The same enzyme species was present in either chloroplasts or chromoplasts as judged by PH and temperature profiles, sensitivities towards different inhibitors and relative molecular mass (M ₁ 88 kDa). The activities analyzed showed the typical behaviour of plastid-type polymerases. The results presented here suggest that chromoplasts maintain their DNA synthesis potential in fruit tissue at chloroplast levels. Consequently, the sharp decrease of the plastid chromosome transcription observed at the onset of fruit ripening could not be due to limitations in the availability of template molecules. Other mechanisms must be involved in the inhibition of chromoplast RNA synthesis.

【 授权许可】

Unknown