C2 photosynthesis generates about 3-fold elevated leaf CO2 levels in the C3-C4 intermediate species Flaveria pubescens.
C2 photosynthesis generates about 3-fold elevated leaf CO2 levels in the C3-C4 intermediate species Flaveria pubescens.
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DOI：
10.1093/jxb/eru239
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发表时间：
2014-07
影响因子：
6.9
通讯作者：
Bauwe H
中科院分区：
文献类型：
--
作者：
Keerberg O;Pärnik T;Ivanova H;Bassüner B;Bauwe H
C3-C4 中间黄菊属物种的叶子中，光呼吸使细胞二氧化碳水平提高约 3 倍。这是通过使用基于 14C 的通量组学来确定 Rubisco 体内羧化与氧合比率来证明的。 C3-C4中间植物中基于光呼吸的CO2浓缩机制的形成被视为C4光合作用进化的先决条件，但尚不清楚该机制的效率如何。在这里，建议使用体内 Rubisco 羧化与氧化比率作为评估相对质体内 CO2 水平的代理。这种比率是针对 C3-C4 中间物种 Flaveria pubescens 与密切相关的 C3 植物 F. cronquistii 和 C4 植物 F.trinervia 进行比较而确定的。为此，开发了一个模型来描述光合-光呼吸碳代谢中涉及的主要碳通量和代谢物库，并用于定量评估短期 14CO2 掺入过程中的标记动力学。我们的数据表明，相对于 C3 物种 F. cronquistii，光呼吸 CO2 泵将 C3-C4 中间物种 F. pubescens 叶子中质体内 CO2 浓度提高了约 3 倍。
Photorespiration raises cellular CO2 levels about 3-fold in leaves of C3–C4 intermediate Flaveria species. This was shown by using 14C-based fluxomics to determine the Rubisco in vivo carboxylation-to-oxygenation ratios. Formation of a photorespiration-based CO2-concentrating mechanism in C3–C4 intermediate plants is seen as a prerequisite for the evolution of C4 photosynthesis, but it is not known how efficient this mechanism is. Here, using in vivo Rubisco carboxylation-to-oxygenation ratios as a proxy to assess relative intraplastidial CO2 levels is suggested. Such ratios were determined for the C3–C4 intermediate species Flaveria pubescens compared with the closely related C3 plant F. cronquistii and the C4 plant F. trinervia. To this end, a model was developed to describe the major carbon fluxes and metabolite pools involved in photosynthetic–photorespiratory carbon metabolism and used quantitatively to evaluate the labelling kinetics during short-term 14CO2 incorporation. Our data suggest that the photorespiratory CO2 pump elevates the intraplastidial CO2 concentration about 3-fold in leaves of the C3–C4 intermediate species F. pubescens relative to the C3 species F. cronquistii.
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影响因子：
7.4
作者：
HOLADAY, AS;CHOLLET, R
通讯作者：
CHOLLET, R
影响因子：
6.9
作者：
Kubien, David S.;Whitney, Spencer M.;Jesson, Linley K.
通讯作者：
Jesson, Linley K.
影响因子：
4.3
作者：
HOLADAY, AS;LEE, KW;CHOLLET, R
通讯作者：
CHOLLET, R
影响因子：
10.1
作者：
MONSON, RK;EDWARDS, GE;KU, MSB
通讯作者：
KU, MSB
影响因子：
7.3
作者：
Kopriva, S;Chu, CC;Bauwe, H
通讯作者：
Bauwe, H