Engineering of Enhancing Electron Transport Rate in Thylakoid Membranes

Improving the photosynthetic efficiency of plants contributes to increased crop yields. Lifeasible has successfully developed a variety of reliable and economical solutions for engineering chloroplast photosynthesis. Here, our engineers focused on improving photosynthetic rates and plant productivity by enhancing electron transport rates in thylakoid membranes through chloroplast genetic engineering.

Introduction

Light reactions in plant photosynthesis are driven by linear and cyclic electron transport around photosystem I (PS I). Among them, linear electron transfer produces both ATP and NADPH, while PSI cyclic electron transfer only produces ATP but not NADPH. The resulting ATP and NADPH are used to power photosynthetic carbon reduction. Furthermore, PSI cyclic electron transport is believed to be critical for balancing the ATP/NADPH production ratio and protecting the two photosystems from damage caused by excessive reduction of the substrate. Therefore, depending on environmental stress and/or physiological conditions, enhancing the photoprotective ability of plants by tuning linear electron transport versus PS I cyclic electron transport may be a way to improve plant tolerance to various environmental stresses in suboptimal environments way.

Fig. 1. Schematic diagram of electron transport in thylakoid membranes in higher plants. (Yamori W, et al., 2016)

Solutions

In recent years, regulation of electron transport in the PSI cycle is very promising in enhancing photosynthesis and plant growth. Based on the chloroplast transformation technology platform, Lifeasible can provide specialized solutions to enhance the electron transfer rate of thylakoid membranes. Our goal is an increase in plant biomass through genetic manipulation of photosynthetic electron transfer.

On the one hand, our engineers tried to tune linear electron transport and PSI cyclic electron transport to enhance the photoprotective ability of plants and promote plant growth. In addition, the cytochrome b6/f (cytb₆/f) complex located in the thylakoid membrane has a unique role in chloroplast electron transport and is a key determinant of electron transport rate. Therefore, we also hope to improve photosynthesis by genetic manipulation of cytb₆/f. In response to the above two solutions, we adopted the following strategies to enhance the electron transport rate of thylakoid membranes.

• The introduction of parallel electron carriers between the cytb₆/f complex and PS I enhances the electron transport rate.
• Overexpression of Rieske FeS protein in chloroplasts increases cytb₆/f complex levels.
• Overexpression of NADK2 in chloroplasts increases electron transport and CO₂ assimilation rates.
• Chlorophyll d and chlorophyll f were introduced into higher plants to supplement or replace existing chlorophyll to increase the amount of available photon flux.
• Development of plants with TAP38 mutations to increase photosynthetic electron flow.

Attractive Advantages of Our Solutions

• Significantly increases electron transfer rate, CO₂ assimilation and plant biomass.
• Successful enhancement of photosynthesis through genetic modification requires consideration of the energy supply and demand for photosynthesis.
• Our team is knowledgeable about the regulation of electron transport processes in the chloroplast.
• Enhanced photosynthetic performance even under stressful conditions.
• Two mature and economical solutions are available for customers to choose from.

Lifeasible's goal is to provide customers around the world with fully customized chloroplast engineered solutions for enhancing electron transport rate in thylakoid membranes. Our various strategies will fully meet your needs. Please contact us to discuss further details to ensure your next success.

References

1. Yamori W, Shikanai T. (2016) Physiological functions of cyclic electron transport around photosystem I in sustaining photosynthesis and plant growth[J]. Annual review of plant biology. 67: 81-106.
2. Yamori W. (2021) Strategies for engineering photosynthesis for enhanced plant biomass production[J]. Rice Improvement. 31.