Enhancing crop yield by using Rubisco activase to improve photosynthesis under elevated temperatures

Abstract

With the rapid growth of world population, it is essential to increase agricultural productivity to feed the growing population. Over the past decades, many methods have been used to increase crop yields. Despite the success in boosting the crop yield through these methods, global food production still needs to be increased to be on par with the increasing population and its dynamic consumption patterns. Additionally, given the prevailing environmental conditions pertaining to the global temperature increase, heat stress will likely be a critical factor that negatively affects plant biomass and crop yield. One of the key elements hindering photosynthesis and plant productivity under heat stress is the thermo-sensitivity of the Rubisco activase (RCA), a molecular chaperone that converts Rubisco back to active form after it becomes inactive. It would be an attractive and practical strategy to maintain photosynthetic activity under elevated temperatures by enhancing the thermo-stability of RCA. In this context, this review discusses the need to improve the thermo-tolerance of RCA under current climatic conditions and to further study RCA structure and regulation, and its limitations at elevated temperatures. This review summarizes successful results and provides a perspective on RCA research and its implication in improving crop yield under elevated temperature conditions in the future.

Molecular mechanism of Rubisco activase: Dynamic assembly and Rubisco remodeling

“…Thus, enhancing our understanding of the molecular mechanism of Rubisco reactivation by Rca is critical in helping us improve the crop production, either by engineering a highly efficient enzyme or modulating the enzyme function. More details for using Rca as a target to improve crop production can be seen in this review (Wijewardene et al, 2021). It is imperative to acquire this piece of knowledge, which can be applied in crop improvements and carbon fixation efficiency in response to climate changes.…”

Creating Climate-Resilient Crops by Increasing Drought, Heat, and Salt Tolerance

“…Photosynthesis, being the primary limiting factor of yield and biomass production in plants, is controlled by complex mechanisms [118], among which the key enzyme of the CO 2 assimilation pathway, ribulose-1,5-bisphosphate carboxylase/oxygenase, or Rubisco, is regulated by Rubisco activase (RCA). Rubisco, upon binding to RCA, undergoes conformational changes in structure, thus removing the sugar phosphate derivative inhibitors that are tightly bound to both active (carbamylated) and inactive (decarbamylated) sites of Rubisco [119,120]. Even though Rubisco is a thermostable enzyme that could remain active up to 50 • C, the heat labile nature of RCA leads to the inactivation of Rubisco, thereby RCA becomes the limiting factor in the assimilation of CO 2 .…”

“…Subsequently, Cai (2022) [137] showed that AVP1/PP2A-C5-co-overexpressing cotton outperformed wild-type cotton under drought and salt stresses in laboratory conditions and produced a higher fiber yield in field conditions. Wijewardane et al (2020, 2021) [120,138] proved that a heat-tolerant RCA from a desert shrub could be used to improve heat tolerance in transgenic plants, which prompted us to create drought-, heat-, and salt-tolerant cotton by co-overexpressing AVP1 and RCA. Subsequently, we demonstrated that AVP1/RCA-co-overexpressing cotton plants produced the highest fiber yield than wildtype and AVP1-overexpressing cotton plants under single as well as multiple stress conditions in the laboratory.…”

Regulation of Rubisco activity in crops

“…Recent reviews indicate Rca as a promising target for improving crop heat tolerance in the context of climate change (Wijewardene et al ., 2021; Qu et al ., 2023; Sparrow‐Muñoz et al ., 2023). The diversity in the optimum temperature and thermal sensitivity of Rca activity has been linked with the temperature range observed in the respective plant habitat (Salvucci & Crafts‐Brandner, 2004; Yamori et al ., 2006; Carmo‐Silva & Salvucci, 2011; Shivhare & Mueller‐Cajar, 2017).…”