Computational analysis of the productivity potential of CAM
Computational analysis of the productivity potential of CAM
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DOI：
10.1038/s41477-018-0112-2
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发表时间：
2018-03-01
期刊：
影响因子：
18
通讯作者：
Sweetlove, Lee J.
中科院分区：
文献类型：
--
作者：
Shameer, Sanu;Baghalian, Kambiz;Sweetlove, Lee J.
人们对将景天酸代谢 (CAM) 转移到 C-3 作物以提高其水分利用效率非常感兴趣。然而，由于 CAM 生化循环的能量消耗很大，因此尚不清楚这会对产量产生什么影响。通过对 CAM 和 C-3 叶代谢网络的昼夜通量平衡分析，我们发现夜间 CAM 的能量消耗高出三倍。然而，白天关闭气孔后苹果酸脱羧的碳浓缩效应可以完全抵消 CAM 的额外成本。根据 rubisco 的羧化酶和加氧酶活性的合成速率，PEPCK-CAM 亚型的生产率是 C-3 网络的 74-100%。我们的结论是，CAM 不会对生产力造成重大影响，并且将 CAM 工程化到 C-3 作物中可能会导致用水效率大幅提高，而不会显着影响产量。
There is considerable interest in transferring crassulacean acid metabolism (CAM) to C-3 crops to improve their water-use efficiency. However, because the CAM biochemical cycle is energetically costly, it is unclear what impact this would have on yield. Using diel flux balance analysis of the CAM and C-3 leaf metabolic networks, we show that energy consumption is three-fold higher in CAM at night. However, this additional cost of CAM can be entirely offset by the carbon-concentrating effect of malate decarboxylation behind closed stomata during the day. Depending on the resultant rates of the carboxylase and oxygenase activities of rubisco, the productivity of the PEPCK-CAM subtype is 74-100% of the C-3 network. We conclude that CAM does not impose a significant productivity penalty and that engineering CAM into C-3 crops is likely to lead to a major increase in water-use efficiency without substantially affecting yield.