Plants can grow with much less light than previously thought, according to a new study on tiny water-based organisms called microalgae that has been published in Nature Communications. The German-led team of researchers lowered light sensors into Arctic water to a depth of 50 metres to test how low light levels must become before plant life ceases to exist, with incredible results.
They found that plants were able to perform photosynthesis – the process in which their leaves convert sunlight into energy – with very little light indeed.
This discovery offers several exciting possibilities for the field of plant sciences:
1. Extended growing seasons
Many areas around the world receive too little sunlight because they are far from the equator and endure long winters, or are persistently covered by cloud. The UK is affected by cloud cover, for instance: in 2024 it is on the way to having one of the worst periods of total light hours since the 1900s (only the 1930s and early 1990s were worse).
Now that we know how little light is required for photosynthesis, scientists could develop crops that require much less light to thrive in such places by learning from these Arctic microalgae. By unlocking their genetic potential, many crops could benefit by using plant breeding or biotech approaches to alter them accordingly.
In particular, this could help to eke more out of short growing seasons and increase food production. Even in a relatively southerly place like the UK, breeding plants that can photosynthesise with less light would potentially increase crop yields.
2. Sustainable agriculture
There could be additional benefits for growing plants indoors such as in greenhouses, polytunnels or vertical farms (where crops are grown in vertically stacked layers, such as racks of shelves). These systems sometimes rely on artificial lighting, which is both energy-intensive and costly.
3. Space farming
Perhaps one of the most exciting prospects of this research is that it could potentially make it easier to grow plants in space. One of the main challenges for space missions to the Moon, Mars or eventually beyond, is how to feed anyone trying to live in those worlds for any length of time. Sunlight can be limited, so we’ll need highly efficient ways of producing food that don’t use much energy.