Na+‐induced uptake of pyruvate into mesophyll chloroplasts of a C4 plant, Panicum miliaceum

FEBS Letters

Ohnishi, Jun-Ichi¹  Kanai, Ryuzi¹ 

[1] Department of Biochemistry, Faculty of Science, Saitama University, Urawa 338, Japan

关键词: Pyruvate transport;    Chloroplast membrane;    Mesophyll chloroplast;    C4 photosynthesis;    Na+ jump;    (Panicum miliaceum);    MCp;    mesophyll chloroplasts;    PEP;    phosphoenolpyruvate;    Pyr;    pyruvate;    [Pyr]in;    pyruvate concentration in the sorbitol-impermeable space of chloroplasts;    [Pyr]ex;    pyruvate concentration in the external medium;   

DOI  :  10.1016/0014-5793(87)80250-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Uptake of [1-¹⁴C]pyruvate into the sorbitol-impermeable space of mesophyll chloroplasts of a C₄ plant, Panicum miliaceum L., was investigated using a silicone oil filtering centrifugation method. An abrupt change of Na⁺ concentration in the suspending medium of the chloroplasts in the dark induced accumulation of pyruvate in the stroma, similar to the case of light-driven active uptake. The effect was specific to Na⁺ among various mono- and divalent cations. The apparent K _m for Na⁺ was in the range 2–5 mM. The K _m for pyruvate was about 0.7 mM, which was similar to the value obtained in light-driven uptake. The possible role of Na⁺ symport in active pyruvate uptake by C₄ mesophyll chloroplasts is discussed.

【 授权许可】

Unknown