Photorespiration is a major bioengineering target for increasing crop yields as it is often considered a wasteful process. Photorespiratory metabolism is integrated into leaf metabolism and thus may have certain benefits. Here, we show that plants can increase their rate of photosynthetic CO₂ uptake when assimilating nitrogen de novo via the photorespiratory pathway by fixing carbon as amino acids in addition to carbohydrates. Plants fed NO₃^- had higher rates of CO₂ assimilation under photorespiratory than low-photorespiratory conditions, while plants lacking NO₃^- nutrition exhibited lower stimulation of CO₂ uptake. We modified the widely used Farquhar, von Caemmerer and Berry photosynthesis model to include the carbon and electron requirements for nitrogen assimilation via the photorespiratory pathway. Our modified model improves predictions of photosynthetic CO₂ uptake and of rates of photosynthetic electron transport. The results highlight how photorespiration can improve photosynthetic performance despite reducing the efficiency of Rubisco carboxylation.

中文翻译：

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植物通过光呼吸途径吸收氮，从而增加了二氧化碳的吸收。

光呼吸是提高作物产量的主要生物工程目标，因为通常认为这是浪费过程。光呼吸代谢被整合到叶片代谢中，因此可能具有一定的益处。在这里，我们表明植物通过光呼吸途径从头吸收氮时，除了将碳水化合物固定为氨基酸外，还可以提高植物光合作用的CO ₂吸收率。供给植物NO ₃ ^-有CO的更高的速率₂下光呼吸比低光呼吸条件同化，而植物缺乏NO ₃ ^-营养表现出CO的低刺激₂摄取。我们修改了广泛使用的Farquhar，von Caemmerer和Berry光合作用模型，以包括通过光呼吸途径吸收氮的碳和电子需求。我们的修改后的模型改善了对光合作用CO ₂吸收和光合作用电子传输速率的预测。该结果突出了光呼吸如何尽管降低了Rubisco羧化的效率却可以改善光合性能。