Related Experiment Video
Updated: Nov 16, 2025

Evaluation of Photosynthetic Efficiency in Photorespiratory Mutants by Chlorophyll Fluorescence Analysis
Published on: December 9, 2022
Co-overproducing Rubisco and Rubisco activase enhances photosynthesis in the optimal temperature range in rice
Mao Suganami1, Yuji Suzuki2, Youshi Tazoe1
1Graduate School of Agricultural Science, Tohoku University, Sendai 980-8572, Japan.
Abstract:
Rubisco limits C3 photosynthesis 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 in RBCS-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 in RBCS-RCA-ox plants was enhanced, the rates of CO2 assimilation at 25°C in RBCS-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 CO2 assimilation in RBCS-ox and RBCS-RCA-ox plants were higher than in wild-type plants under conditions equal to or lower than current atmospheric CO2 levels. The activation state of Rubisco in RBCS-RCA-ox remained higher than that of RBCS-ox plants, and activated Rubisco content in RCA overproducing, RBCS-ox, RBCS-RCA-ox, and wild-type plants was highly correlated with the initial slope of CO2 assimilation against intercellular CO2 pressures (A:Ci) at 36°C. Thus, a simultaneous increase in Rubisco and RCA contents leads to enhanced photosynthesis within the optimal temperature range.
More Related Videos
05:44Real-Time Detection of Reactive Oxygen Species Production in Immune Response in Rice with a Chemiluminescence Assay
Published on: November 25, 2022
07:43Agrobacterium-Mediated Genetic Transformation, Transgenic Production, and Its Application for the Study of Male Reproductive Development in Rice
Published on: October 6, 2020
Related Concept Videos
The Calvin Benson Cycle
C4 Pathway and CAM
C4 Pathway
The C4 pathway is used by plants such as...
Responses to Drought and Flooding
Adaptations that Reduce Water Loss
Carbon-dioxide Fixation
Responses to Heat and Cold Stress