The Future of Plant Canopies: Harnessing Far-Red Light for a Major Productivity Boost — Insights from a Simulation Study

Introduction — Far-Red Light as an Untapped Resource

When we think of photosynthesis, we usually imagine plants using visible light in the range of 400–700 nanometers. Most crop leaves absorb about 90% of this spectrum and convert it into sugars, which serve as the plant’s main energy source. In contrast, far-red light (700–800 nanometers) easily passes through the upper canopy layers and reaches the shaded lower leaves in abundance, yet plants make little use of it. As a result, the lower canopy is often light-limited, receiving mainly far-red wavelengths that cannot be efficiently used for photosynthesis.

The study published in Nature Communications in August 2025 asked a fascinating question: What would happen if crops could absorb and utilize far-red light more effectively, especially in their lower leaves? By conducting advanced three-dimensional field simulations based on real soybean data, the researchers estimated that the total daily carbon dioxide assimilation of a crop canopy could increase by up to 26% with the introduction of far-red–absorbing chlorophylls (chlorophyll d and chlorophyll f). These figures should be interpreted as theoretical possibilities, since the work was based on simulations rather than real-world genetically engineered plants. Nevertheless, the model is highly realistic, incorporating canopy structure, light spectra, heat balance, and gas exchange, making the results highly credible.

Reference： Addition of longer wavelength absorbing chlorophylls into crops could increase their photosynthetic productivity by 26%

Research Background — From a Single Leaf to the Whole Canopy

Past studies on photosynthesis have largely focused on single leaves or individual cells. However, real crop fields are composed of multiple overlapping layers of leaves, and the direction, intensity, and spectral composition of light change throughout the day. Upper leaves absorb almost all visible light and reach saturation, while lower leaves are left in a dim environment dominated by far-red light. This uneven distribution reduces the contribution of lower leaves to overall photosynthetic productivity. A key concept here is the far-red to red light ratio (FR/R ratio), which becomes greater than 1 as one goes deeper into the canopy.

Interestingly, some organisms in nature have already developed ways to use far-red light. Cyanobacteria, for example, possess a system called far-red light photoacclimation, which enables them to increase the production of chlorophyll d and chlorophyll f under far-red–rich conditions. These pigments allow absorption of light up to 800 nanometers, capturing energy that normal chlorophylls cannot use efficiently. If higher plants could be engineered to produce and properly utilize these pigments in their shaded leaves, it could potentially convert unused far-red light into extra energy, increasing yield at the canopy scale. Until this study, however, such potential gains had not been quantified.

Methods — Virtual Fields and 3D Canopy Simulations

The research team selected soybean fields as a model system and reconstructed realistic three-dimensional canopy structures that represented different stages of growth. They fed actual solar radiation data (based on the AM1.5 spectrum) into a ray-tracing model, which calculated how blue, green, red, and far-red light were absorbed, transmitted, or reflected at each individual leaf surface.

The light distribution data were then linked with a well-established photosynthesis model known as the Farquhar–von Caemmerer–Berry model, which describes processes such as carbon dioxide assimilation, stomatal conductance, transpiration, and leaf temperature. By integrating the canopy-scale light environment with leaf-level physiology, the team was able to estimate daily totals of photosynthetic carbon assimilation, transpiration, water-use efficiency, and leaf temperature.

Two main scenarios were considered. In the first, all leaves in the canopy were given the same capacity to absorb far-red light. In the second, far-red absorption was enhanced specifically in the lower canopy leaves, where the FR/R ratio is naturally higher. This second approach was designed to avoid excessive light capture and heat stress in the upper canopy, while boosting light use in the shaded lower leaves. Simulations were performed across different growth stages, revealing how the potential benefits varied over time.

Results — Significant Gains in Carbon Fixation and Water Use

When the model simulated the introduction of chlorophyll d, which mainly absorbs light between 701 and 750 nanometers, and allowed its absorption to increase in the lower canopy, the total daily carbon dioxide assimilation increased by about 13.7%. This result indicates that the shaded leaves could significantly contribute to the overall productivity once they can capture far-red light efficiently.

When chlorophyll f, which absorbs light up to 800 nanometers, was tested under the same scenario, the potential effect was even greater. The simulations predicted a 26.1% increase in daily carbon fixation and a 22.7% increase in daily light absorption. Interestingly, water-use efficiency also improved slightly, by 0.8–1.2%. The increase in leaf temperature from additional far-red absorption was limited to less than 1°C at midday, suggesting manageable heat stress risks.

These results also emphasize the importance of spatiotemporal regulation. During early vegetative stages, when sunlight reaches all leaves, the effect of far-red absorption is small. In contrast, in dense canopies during reproductive stages, targeting far-red absorption to shaded leaves yields the greatest benefits.

Discussion — Innovation and Challenges

The novelty of this research lies in demonstrating through simulation that expanding the usable light spectrum can boost photosynthesis at the scale of entire crop canopies, not only individual leaves. Designing plants to make use of far-red light specifically in their lower leaves could enhance overall productivity while minimizing risks such as heat stress and photoinhibition in upper leaves. This approach is complementary to existing strategies such as improving the efficiency of the key enzyme Rubisco or accelerating photoprotection recovery.

At the same time, significant challenges remain before this concept can be realized in the field. Although the enzyme responsible for producing chlorophyll f has already been identified in cyanobacteria, the complete biosynthetic pathway of chlorophyll d is still unclear. Moreover, introducing these pigments into higher plants is not sufficient on its own. The binding sites of photosynthetic proteins would need to be engineered so that chlorophyll d and f could integrate smoothly and transfer excitation energy efficiently. Laboratory studies have shown that plant light-harvesting complexes can indeed accommodate these pigments, suggesting that fine-tuned molecular engineering is feasible. Still, multiple steps of optimization and field validation are required.

Another important issue is water use efficiency. Since using far-red light increases overall light absorption, it can also increase transpiration. Under well-watered conditions, the gain in carbon assimilation outweighs the additional water loss, resulting in a slight improvement in efficiency. However, under drought conditions, there is a risk that higher water demand could suppress growth. Therefore, combining far-red chlorophyll introduction with water management strategies, improved stomatal responsiveness, or enhanced root water uptake will be essential.

Plant Hack Perspective — Designing the Light Spectrum

From the perspective of Plant Hack, which emphasizes creative approaches to unlocking plant potential, this research is especially inspiring. It suggests that agriculture could move beyond traditional breeding or enzyme optimization and start focusing on engineering plants to make use of light wavelengths that are currently wasted. In controlled environments such as greenhouses, where light-emitting diodes are already standard, supplementing with far-red light and coupling it with strategic leaf-level pigment expression may allow plants to photosynthesize more evenly throughout the canopy. In open fields as well, a combination of genetic engineering, canopy architecture design, and irrigation management could allow crops to convert unused far-red light into additional yield.

Looking to the future, this line of research may also serve as a foundation for quantum computing–based agricultural innovation. Photosynthetic energy transfer involves quantum mechanical phenomena, and the vast optimization challenges of regulating pigment expression in space and time could one day be addressed more effectively with quantum algorithms. In this sense, the study not only explores a potential leap in photosynthetic efficiency but also hints at how agriculture might evolve in tandem with emerging computational technologies.

Conclusion — A Future Beyond “Not Yet”

This study demonstrates, through detailed three-dimensional simulations grounded in real field data, how introducing chlorophyll d and f into crop leaves could theoretically increase whole-canopy photosynthesis. The most optimistic scenario suggests that daily carbon dioxide assimilation could rise by about 26%, with water-use efficiency improving by 0.8–1.2%. While practical challenges remain—such as deciphering chlorophyll d biosynthesis, optimizing pigment–protein interactions, and managing water use—the potential benefits are significant.

Ultimately, this work paints a vivid picture of a future where designed photosynthesis allows crops to harvest light more completely. It shows that simulation-based research can guide us toward realistic strategies for enhancing crop yields, and it also anticipates the coming era when quantum computing may help solve the complex optimization problems of agriculture. It is not yet reality, but it is a future that seems increasingly within reach.

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Glossary

• Far-red light: Light with wavelengths between 700–800 nanometers, which penetrates deeper into plant canopies than visible red light.
• Far-red/red ratio (FR/R ratio): The balance between far-red and red light; this ratio increases deeper inside dense canopies.
• Chlorophyll d / f: Special chlorophyll variants found in cyanobacteria that can absorb far-red light up to 800 nanometers.
• Far-red light photoacclimation: An adaptive mechanism in cyanobacteria that increases chlorophyll d/f under far-red–rich conditions.