Spatial photosynthesis modelling sets guidelines to constructing a viable single-cell cytoplasm-to-stroma C 4 cycle
Spatial photosynthesis modelling sets guidelines to constructing a viable single-cell cytoplasm-to-stroma C 4 cycle
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空间光合作用模型为构建可行的单细胞细胞质到基质 C 4 循环提供了指导
DOI：
10.1101/274845
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Juric I
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文献类型：
--
作者：
Juric I
有人提出，将c4光合作用引入c3作物可以提高产量。最简单的方案是在不改变叶片或细胞解剖结构的情况下，将叶肉细胞叶绿体基质中来自细胞质的碳浓缩。光合效率在很大程度上取决于叶绿体包膜对二氧化碳的渗透性。我们利用c3叶肉细胞几何碳同化的空间模型来研究这一c4循环的性能，对c4光合作用的相关参数空间进行了深入的探索。当包膜渗透率低于300 μ m/s时，c4光合作用的量子效率高于C3。然而，即使当包膜通透性高于这个阈值时，c4途径也可以提供大量的碳同化，而效率只会适度降低。根据质体的光收集能力，c4光合作用可以在任何地方提高20%到100%的碳吸收。在二氧化碳剥夺的情况下，收益更为显著，如果叶绿体表面覆盖也发生改变，则可以在质体投资减少的同时实现收益。因此，c3植物的单个叶肉细胞内的c4通路可以在干燥、高日照气候下导致更高的生长速率和更好的抗旱性。
It has been proposed that introducing C4photosynthesis into C3crops would increase yield. The simplest scheme in- volves concentrating carbon originating from the cytosol in the chloroplast stroma of mesophyll cells without altering leaf or cell anatomy. Photosynthetic efficiency would then strongly depend on the chloroplast envelope permeability to CO2. We examine the performance of this C4cycle with a spatial model of carbon assimilation in C3mesophyll cell geometry, conducting a thorough exploration of parameter space relevant to C4photosynthesis. For envelope perme- abilities below 300 µm/s C4photosynthesis has a higher quantum efficiency than C3. However, even when envelope permeability is above this threshold, the C4pathway can provide a substantial boost to carbon assimilation with only a moderate decrease in efficiency. Depending on the available light-harvesting capacity of plastids, C4photosynthesis could boost carbon assimilation anywhere from 20% to 100%. Gains are even more prominent under CO2deprivation, and can be achieved in conjunction with lower investment in plastids if chloroplast surface coverage is also altered. A C4pathway operating within individual mesophyll cells of C3plants could hence lead to higher growth rates and better drought resistance in dry, high-sunlight climates.