The efficiency of the CO2-concentrating mechanism during single-cell C4 photosynthesis
The efficiency of the CO2-concentrating mechanism during single-cell C4 photosynthesis
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DOI：
10.1111/j.1365-3040.2011.02431.x
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发表时间：
2012-03-01
影响因子：
7.3
通讯作者：
Cousins, Asaph B.
中科院分区：
文献类型：
--
作者：
King, Jenny L.;Edwards, Gerald E.;Cousins, Asaph B.
对藜科植物两种单细胞C4光合作用形式的CO2浓缩机制的光合效率进行了表征。Bienertioid型单细胞C4使用外周和中央细胞质隔室（Bienertiasinspersici），而Borszczowioid单细胞C4使用细胞的远端和近端隔室（碱蓬）。C4光合作用在一个单一的细胞提出的问题，这种类型的CO2浓缩机制相比，克兰兹型的效率。我们使用的测量叶片CO2同位素交换（13 C）的效率进行比较的单细胞和克兰兹型形式的C4光合作用在不同的温度和光照条件下。比较了单细胞C4和姐妹Kranz形式S。eltonica[NAD苹果酸酶（NAD ME）型]和黄顶菊[NADP苹果酸酶（NADP-ME）型与Kranz Atriplicoid解剖结构]。与Kranz型相比，单细胞物种的13 C歧视和CO2泄漏水平相似。增加叶温（25至30摄氏度）和光照强度导致13摄氏度和所有C4类型的减少。值得注意的是，B。sinuspersici的~（13）C含量高于S. aralocaspica在较低的光。这些结果表明，单细胞C4植物的光合作用速率和CO2浓缩机制的效率与Kranz型植物相似。
The photosynthetic efficiency of the CO2-concentrating mechanism in two forms of single-cell C4 photosynthesis in the family Chenopodiaceae was characterized. The Bienertioid-type single-cell C4 uses peripheral and central cytoplasmic compartments (Bienertia sinuspersici), while the Borszczowioid single-cell C4 uses distal and proximal compartments of the cell (Suaeda aralocaspica). C4 photosynthesis within a single-cell raises questions about the efficiency of this type of CO2-concentrating mechanism compared with the Kranz-type. We used measurements of leaf CO2 isotope exchange (13C) to compare the efficiency of the single-cell and Kranz-type forms of C4 photosynthesis under various temperature and light conditions. Comparisons were made between the single-cell C4 and a sister Kranz form, S. eltonica[NAD malic enzyme (NAD ME) type], and with Flaveria bidentis[NADP malic enzyme (NADP-ME) type with Kranz Atriplicoid anatomy]. There were similar levels of 13C discrimination and CO2 leakiness in the single-cell species compared with the Kranz-type. Increasing leaf temperature (25 to 30 degrees C) and light intensity caused a decrease in 13C and across all C4 types. Notably, B. sinuspersici had higher 13C and than S. aralocaspica under lower light. These results demonstrate that rates of photosynthesis and efficiency of the CO2-concentrating mechanisms in single-cell C4 plants are similar to those in Kranz-type.