Addition of longer wavelength absorbing chlorophylls into crops could increase their photosynthetic productivity by 26.

Abstract

Crop leaves absorb approximately 90% of visible photons (400 - 700 nm) but transmit or reflect most far-red (FR) photons (700 - 800 nm). However, some cyanobacteria use FR photons up to 800 nm by incorporating chlorophyll (Chl) d or/and f into their photosystems. Here, we use a 3D canopy model to evaluate whether introducing these pigments could improve photosynthetic performance of field grown soybean. We simulate photon absorption and CO₂ assimilation show that the introduction of Chl d and f would significantly enhance photosynthesis, especially in the lower canopy, where visible light is depleted and FR light is abundant. When FR absorption is regulated by phytochrome-sensed FR/red (FR/R) photon ratio, the benefit is further increased, with canopy CO₂ assimilation improving up to 26%, without increasing the risk of photodamage. These results show that introducing FR-absorbing Chls into crops could have great value in boosting productivity.