Na+‐induced uptake of pyruvate into mesophyll chloroplasts of a C4 plant, Panicum miliaceum
Na+‐induced uptake of pyruvate into mesophyll chloroplasts of a C4 plant, Panicum miliaceum
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DOI：
10.1016/0014-5793(87)80250-8
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发表时间：
1987-07
期刊：
影响因子：
3.5
通讯作者：
J. Ohnishi;R. Kanai
中科院分区：
文献类型：
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作者：
J. Ohnishi;R. Kanai
用硅油过滤离心法研究了C4植物水稻叶肉叶绿体[1-14C]丙酮酸对山梨醇不透性空间的吸收。黑暗中叶绿体悬浮液中Na+浓度的突然变化会诱导基质中丙酮酸的积累，类似于光驱动的主动吸收。这种影响是对各种一价和二价阳离子中的Na+所特有的。Na+的表观Km在2-5 mm范围内。丙酮酸的Km约为0.7 mm，与光驱动吸收的Km相近。讨论了Na+信号转运蛋白在C4叶绿体主动吸收丙酮酸中的可能作用。
Uptake of [1‐14C]pyruvate into the sorbitol‐impermeable space of mesophyll chloroplasts of a C4plant,Panicum miliaceumL., 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 apparentKmfor Na+was in the range 2–5 mM. TheKmfor 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 C4mesophyll chloroplasts is discussed.