Co-overproducing Rubisco and Rubisco activase enhances photosynthesis in the optimal temperature range in rice
Co-overproducing Rubisco and Rubisco activase enhances photosynthesis in the optimal temperature range in rice
复制标题
共同过量产生 Rubisco 和 Rubisco 激活酶可增强水稻在最佳温度范围内的光合作用
DOI：
10.1093/plphys/kiaa026
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发表时间：
2021
期刊：
影响因子：
7.4
通讯作者：
Makino Amane
中科院分区：
文献类型：
--
作者：
Suganami Mao;Suzuki Yuji;Tazoe Youshi;Yamori Wataru;Makino Amane
Rubisco在某些条件下限制C3光合作用，因此是提高光合效率的潜在目标。Rubisco的过量产生通常伴随着Rubisco活化的下降，并且在Rubisco过量产生的植物（RBCS-ox）中，Rubisco活化酶（RCA）与Rubisco的蛋白质比率（RCA/Rubisco）大大降低。在这里，我们产生了转基因水稻（Oryza sativa）植物，其同时过量产生Rubisco和RCA（RBCS-RCA-ox）。RBCS-RCA-ox植株的Rubisco含量增加23%-44%，RCA/Rubisco值接近或高于野生型植株。然而，尽管RBCS-RCA-ox植物中Rubisco的活化状态增强，但RBCS-RCA-ox植物在25°C下的CO2同化速率与野生型植物没有差异。另外，在中等高温（最佳温度范围为32°C-36°C）下，RBCS-ox和RBCS-RCA-ox植物的CO2同化率高于野生型植物，条件等于或低于当前大气CO2水平。RBCS-RCA-ox植株的Rubisco活性高于RBCS-ox植株，并且在36°C时，RCA超量植株、RBCS-ox、RBCS-RCA-ox和野生型植株的活化Rubisco含量与CO2同化对胞间CO2压力的初始斜率（A：Ci）高度相关。因此，Rubisco和RCA含量的同时增加导致在最佳温度范围内增强的光合作用。
Rubisco limits C3photosynthesis under some conditions and is therefore a potential target for improving photosynthetic efficiency. The overproduction of Rubisco is often accompanied by a decline in Rubisco activation, and the protein ratio of Rubisco activase (RCA) to Rubisco (RCA/Rubisco) greatly decreases in Rubisco-overproducing plants (RBCS-ox). Here, we produced transgenic rice (Oryza sativa) plants co-overproducing both Rubisco and RCA (RBCS-RCA-ox). Rubisco content inRBCS-RCA-ox plants increased by 23%–44%, and RCA/Rubisco levels were similar or higher than those of wild-type plants. However, although the activation state of Rubisco inRBCS-RCA-ox plants was enhanced, the rates of CO2assimilation at 25°C inRBCS-RCA-ox plants did not differ from that of wild-type plants. Alternatively, at a moderately high temperature (optimal range of 32°C–36°C), the rates of CO2assimilation inRBCS-ox andRBCS-RCA-ox plants were higher than in wild-type plants under conditions equal to or lower than current atmospheric CO2levels. The activation state of Rubisco inRBCS-RCA-ox remained higher than that ofRBCS-ox plants, and activated Rubisco content inRCAoverproducing,RBCS-ox,RBCS-RCA-ox, and wild-type plants was highly correlated with the initial slope of CO2assimilation against intercellular CO2pressures (A:Ci) at 36°C. Thus, a simultaneous increase in Rubisco and RCA contents leads to enhanced photosynthesis within the optimal temperature range.