Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA; email:
Departments of Plant Biology and Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
Annu Rev Plant Biol. 2022 May 20;73:617-648. doi: 10.1146/annurev-arplant-070221-024745.
Photosynthesis is an important remaining opportunity for further improvement in the genetic yield potential of our major crops. Measurement, analysis, and improvement of leaf CO assimilation () have focused largely on photosynthetic rates under light-saturated steady-state conditions. However, in modern crop canopies of several leaf layers, light is rarely constant, and the majority of leaves experience marked light fluctuations throughout the day. It takes several minutes for photosynthesis to regain efficiency in both sun-shade and shade-sun transitions, costing a calculated 10-40% of potential crop CO assimilation. Transgenic manipulations to accelerate the adjustment in sun-shade transitions have already shown a substantial productivity increase in field trials. Here, we explore means to further accelerate these adjustments and minimize these losses through transgenic manipulation, gene editing, and exploitation of natural variation. Measurement andanalysis of photosynthesis in sun-shade and shade-sun transitions are explained. Factors limiting speeds of adjustment and how they could be modified to effect improved efficiency are reviewed, specifically nonphotochemical quenching (NPQ), Rubisco activation, and stomatal responses.
光合作用是进一步提高主要作物遗传产量潜力的重要剩余机会。叶片 CO 同化（）的测量、分析和改进主要集中在光饱和稳态条件下的光合速率上。然而，在现代多层叶片的作物冠层中，光很少是恒定的，大多数叶片在一天中会经历明显的光波动。在阳光和阴影的过渡中，光合作用需要几分钟的时间才能恢复效率，这会导致计算出的 10-40%的潜在作物 CO 同化损失。转基因操作以加速阳光和阴影过渡的调整已经在田间试验中显示出了显著的生产力提高。在这里，我们探讨了通过转基因操作、基因编辑和利用自然变异来进一步加速这些调整并最小化这些损失的方法。解释了阳光和阴影过渡中光合作用的测量和分析。综述了限制调整速度的因素以及如何通过改变这些因素来提高效率，具体包括非光化学猝灭（NPQ）、Rubisco 激活和气孔响应。
