Department of Biology, University of York, Heslington, York YO1 5DD, United Kingdom.
Plant Physiol. 1979 Mar;63(3):567-72. doi: 10.1104/pp.63.3.567.
The concentrations of free amino acids and amides within isolated maize (Zea mays L.) plastids were determined and compared with concentrations in the leaf tissue. The concentrations were different for each individual amino acid and varied between 1 and 10 millimolar. At five different developmental stages concentrations in the plastids were greater than those in the intact leaf tissue. During development, from the proplastid stage to the mature chloroplast, the amount of each amino acid per plastid remained relatively constant, but there were decreases in concentrations of plastid amino acids resulting from the developmental increase in plastid volume. In proplastids, the free amino acids were present in greater concentrations than those previously found to inhibit partially amino acid-synthesizing enzymes located in chloroplasts. In the chloroplasts, the molarities of the free amino acids were within the range known to inhibit amino acid-synthesizing enzymes.
测定了分离的玉米（Zea mays L.）质体中游离氨基酸和酰胺的浓度，并与叶片组织中的浓度进行了比较。每种氨基酸的浓度都不同，在 1 到 10 毫摩尔之间变化。在五个不同的发育阶段，质体中的浓度大于完整叶片组织中的浓度。在发育过程中，从前质体阶段到成熟叶绿体，每个质体中的每种氨基酸的量相对保持不变，但由于质体体积的发育增加，质体氨基酸的浓度降低。在前质体中，游离氨基酸的浓度高于先前发现的部分抑制位于叶绿体中的氨基酸合成酶的浓度。在叶绿体中，游离氨基酸的摩尔浓度在已知抑制氨基酸合成酶的范围内。
