Graduate School of Agricultural and Life Science, Institute for Sustainable Agri-ecosystem, The University of Tokyo, Tokyo, Japan.
Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan.
Plant Cell Environ. 2021 Jul;44(7):2308-2320. doi: 10.1111/pce.14051. Epub 2021 Apr 27.
Global warming threatens food security by decreasing crop yields through damage to photosynthetic systems, especially Rubisco activation. We examined whether co-overexpression of Rubisco and Rubisco activase improves the photosynthetic and growth performance of rice under high temperatures. We grew three rice lines-the wild-type (WT), a Rubisco activase-overexpressing line (oxRCA) and a Rubisco- and Rubisco activase-co-overexpressing line (oxRCA-RBCS)-and analysed photosynthesis and biomass at 25 and 40°C. Compared with the WT, the Rubisco activase content was 153% higher in oxRCA and 138% higher in oxRCA-RBCS, and the Rubisco content was 27% lower in oxRCA and similar in oxRCA-RBCS. The CO assimilation rate (A) of WT was lower at 40°C than at 25°C, attributable to Rubisco deactivation by heat. On the other hand, that of oxRCA and oxRCA-RBCS was maintained at 40°C, resulting in higher A than WT. Notably, the dry weight of oxRCA-RBCS was 26% higher than that of WT at 40°C. These results show that increasing the Rubisco activase content without the reduction of Rubisco content could improve yield and sustainability in rice at high temperature.
全球变暖通过破坏光合作用系统（尤其是 Rubisco 激活酶）来降低作物产量，从而威胁到粮食安全。我们研究了 Rubisco 和 Rubisco 激活酶的共过表达是否能提高高温下水稻的光合作用和生长性能。我们种植了三个水稻品系——野生型（WT）、Rubisco 激活酶过表达系（oxRCA）和 Rubisco 和 Rubisco 激活酶共过表达系（oxRCA-RBCS），并在 25°C 和 40°C 下分析了光合作用和生物量。与 WT 相比，oxRCA 中的 Rubisco 激活酶含量高 153%，oxRCA-RBCS 中的 Rubisco 激活酶含量高 138%，而 oxRCA 中的 Rubisco 含量低 27%，oxRCA-RBCS 中的 Rubisco 含量相似。WT 在 40°C 时的 CO 同化率（A）低于 25°C，这归因于热对 Rubisco 的失活。另一方面，oxRCA 和 oxRCA-RBCS 的 A 在 40°C 时得以维持，导致其 A 高于 WT。值得注意的是，oxRCA-RBCS 在 40°C 时的干重比 WT 高 26%。这些结果表明，在不降低 Rubisco 含量的情况下增加 Rubisco 激活酶含量可以提高水稻在高温下的产量和可持续性。
