Group Research and Development, Philip Lyle Memorial Research Laboratory, Tate and Lyle Ltd., P.O. Box 68, RG6 2BX, Reading, Berks, UK.
Planta. 1973 Jun;110(2):121-9. doi: 10.1007/BF00384834.
The anatomical structure of leaf tissue of P. purpureum, and the short term labelling pattern following exposure to (14)CO2 in the lighht, have been investigated. Both the arrangement of photosynthetic tissue in two layers around the vascular tissue, and the early labelling of malate and aspartate, characteristic of C-4 plants were observed. The structure of the epidermis and the arrangement of stomata is such that CO2 must pass through non-chloroplast-containing tissue before reaching the chloroplasts. At 0.05% CO2 in air the rate of photosynthetic CO2 assimilation was about 70 μmoles/mg chl·h. This increased to over 700 μmoles/mg chl·h at saturating concentrations of CO2. At 0.05% CO2 negative slopes were obtained from percentage plots for malate, which was the major product. As the CO2 concentration was increased, sugar phosphates became the major product. At saturating concentrations of CO2, both malate and aspartate had positive initial slopes and a negative slope was observed for phosphoglyceric acid. These results are discussed in relation to the contribution of C-4 metabolism to photosynthesis in P. purpureum.
已经研究了 P. purpureum 叶组织的解剖结构，以及在光照下暴露于 (14)CO2 后的短期标记模式。观察到了两层光合组织围绕维管束排列的情况，以及苹果酸和天冬氨酸的早期标记，这是 C-4 植物的特征。表皮的结构和气孔的排列使得 CO2 必须通过不含叶绿体的组织才能到达叶绿体。在空气中 0.05% CO2 的浓度下，光合作用 CO2 同化的速率约为 70 μmoles/mg chl·h。当 CO2 浓度达到饱和时，这个速率增加到超过 700 μmoles/mg chl·h。在空气中 0.05% CO2 的浓度下，从苹果酸的百分比图中得到了负斜率，苹果酸是主要产物。随着 CO2 浓度的增加，糖磷酸成为主要产物。在 CO2 浓度饱和时，苹果酸和天冬氨酸都有正的初始斜率，而磷酸甘油酸则观察到负斜率。这些结果与 C-4 代谢对 P. purpureum 光合作用的贡献有关。
