Far-red
In efforts to increase photosynthetic efficiency, researchers have proposed extending the spectrum of light that is available for photosynthesis. One approach involves incorporating pigments like chlorophyll d and f, which are capable of absorbing far-red light, into the photosynthetic machinery of higher plants. Naturally present in certain cyanobacteria, these chlorophylls enable photosynthesis with far-red light that standard chlorophylls a and b cannot utilize. By adapting these pigments for use in higher plants, it is hoped that plants can be engineered to utilize a wider range of the light spectrum, potentially leading to increased growth rates and biomass production.
Green
Green light is considered the least efficient wavelength in the visible spectrum for photosynthesis and presents an opportunity for increased utilization. Chlorophyll c is a pigment found in marine algae with blue-green absorption and could be used to expand absorption in the green wavelengths in plants. Expression of the dinoflagellate CHLOROPHYLL C SYNTHASE gene in the plant Nicotiana benthamiana resulted in the heterologous production of chlorophyll c. This was the first successful introduction of a foreign chlorophyll molecule into a higher plant and is the first step towards bioengineering plants for improved photosynthetic performance across a variety of lighting conditions.