In several systems, from plant's canopy to algal bioreactors, the decrease of the antenna size has been proposed as a strategy to increase the photosynthetic efficiency. However, still little is known about possible secondary effects of such modifications. This is particularly relevant because the modulation of the antenna size is one of the most important light acclimation responses in photosynthetic organisms. In our study, we used an Arabidopsis thaliana mutant (dLhcb2), which has a 60% decrease of Lhcb1 and Lhcb2, the two main components of the major Photosystem II antenna complex. We show that the mutant maintains the photosynthetic and photoprotective capacity of the Wild Type (WT) and adapts to different light conditions by remodelling its photosynthetic apparatus, but the regulatory mechanism differs from that of the WT. Surprisingly, it does not compensate for the decreased light-harvesting capacity by increasing other pigment-protein complexes. Instead, it lowers the ratio of the cytochrome b6 f and ATP synthase to the photosystems, regulating linear electron flow and maintaining the photosynthetic control at the level of these complexes as in the WT. We show that targeting the reduction of two specific antenna proteins, Lhcb1 and Lhcb2, represents a viable solution to obtain plants with a truncated antenna size, which still maintain the capacity to acclimate to different light conditions.

中文翻译：

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减少Photosystem II天线尺寸对拟南芥光适应能力的影响。

在几种系统中，从植物冠层到藻类生物反应器，已经提出减小天线尺寸是提高光合作用效率的一种策略。但是，对于这种修改的可能的次级影响知之甚少。这一点特别相关，因为天线尺寸的调制是光合生物中最重要的光适应反应之一。在我们的研究中，我们使用了拟南芥突变体（dLhcb2），该突变体将Lhcb1和Lhcb2（主要的Photosystem II天线复合体的两个主要组成部分）降低了60％。我们表明，该突变体保持了野生型（WT）的光合作用和光保护能力，并通过重塑其光合作用装置来适应不同的光照条件，但调控机制不同于WT。出奇，它不能通过增加其他色素-蛋白质复合物来补偿光收集能力的下降。相反，它降低了细胞色素b6f和ATP合酶与光系统的比率，从而调节线性电子流并将光合作用的控制水平维持在WT中。我们表明，针对两种特定的天线蛋白Lhcb1和Lhcb2的减少，是获得具有截短的天线尺寸的植物的可行解决方案，该植物仍保持了适应不同光照条件的能力。像在WT中一样，调节线性电子流并将光合作用保持在这些配合物的水平上。我们表明，针对两种特定的天线蛋白Lhcb1和Lhcb2的减少，是获得具有截短的天线尺寸的植物的可行解决方案，该植物仍保持了适应不同光照条件的能力。像在WT中一样，调节线性电子流并将光合作用保持在这些配合物的水平上。我们表明，针对两种特定的天线蛋白Lhcb1和Lhcb2的减少，是获得具有截短的天线尺寸的植物的可行解决方案，该植物仍保持了适应不同光照条件的能力。