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Na + ‐induced uptake of pyruvate into mesophyll chloroplasts of a C 4 plant, Panicum miliaceum
Author(s) -
Ohnishi Jun-Ichi,
Kanai Ryuzi
Publication year - 1987
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(87)80250-8
Subject(s) - chloroplast , symporter , panicum miliaceum , divalent , chemistry , sorbitol , biochemistry , biophysics , botany , biology , transporter , organic chemistry , gene
Uptake of [1‐ 14 C]pyruvate into the sorbitol‐impermeable space of mesophyll chloroplasts of a C 4 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 C 4 mesophyll chloroplasts is discussed.