Mourioux G, Douce R
Biochimie. 1979;61(11-12):1283-92.
Evidence is presented for low rates of carrier-mediated uptake of sulphate, thiosulphate and sulphite into the stroma of the C3 plant Spinacia oleracea. Uptake of sulphate in the dark was followed using two techniques (1) uptake of sulphate [35S] as determined by silicon oil centrifugal filtration and (2) uptake as indicated by inhibition of CO2-dependent O2 evolution rates after addition of sulphate. Sulphate, thiosulphate and sulphite were transported across the envelope leading to an accumulation in the chloroplasts. Sulphate for each molecule of sulphate entering the chloroplast, one molecule of phosphate leaves the stroma, and vice-versa. The uptake of sulphate by isolated intact chloroplasts exchanging for internal free phosphate induced a lower rate of photophosphorylation, which in turn inhibited CO2-dependent O2 evolution. The presence, on the inner membrane of the chloroplasts envelope, of a specific sulphate carrier, distinct from the phosphate translocator, is discussed.
有证据表明，C3植物菠菜叶肉细胞基质中载体介导的硫酸盐、硫代硫酸盐和亚硫酸盐摄取速率较低。采用两种技术跟踪黑暗中硫酸盐的摄取情况：（1）通过硅油离心过滤测定[35S]硫酸盐的摄取量；（2）添加硫酸盐后，通过抑制依赖CO2的O2释放速率来指示摄取情况。硫酸盐、硫代硫酸盐和亚硫酸盐通过包膜运输，导致在叶绿体中积累。每进入叶绿体一分子硫酸盐，就有一分子磷酸盐离开基质，反之亦然。分离的完整叶绿体摄取硫酸盐以交换内部游离磷酸盐，导致光磷酸化速率降低，进而抑制依赖CO2的O2释放。本文讨论了叶绿体包膜内膜上存在一种与磷酸转运体不同的特异性硫酸盐载体。
