Plant circadian systems may be key to sustainable farming

Scientists at the University of Cambridge are describing how a plant’s ability to tell time could be exploited for more sustainable food production. According to the experts, circadian clock genes could be targeted in agriculture and crop breeding for higher yields.

“Circadian biology might have translational impact in crop science through the practice of ‘chronoculture,’ in which the daily timing of agronomic interventions and the genetic basis of circadian rhythms are targets for crop improvements and reduced inputs,” wrote the study authors.

Just like humans, plants have an internal clock that detects daily rhythms in the surrounding environment. Now that there are genetic tools to modify this circadian system, the clock should be exploited in agriculture, explained the researchers.

“We live on a rotating planet, and that has a huge impact on our biology – and on the biology of plants,” said study senior author Professor Alex Webb. “We’ve discovered that plants grow much better when their internal clock is matched to the environment they grow in.”

The circadian clock plays an important role in regulating photosynthesis, flowering time, and many other functions that affect plant yield. Crop breeders could target tie circadian clock genes to gain control of these functions.

For example, the researchers said the simplest and easiest approach would be to use knowledge of a crop’s internal clock to apply water, herbicides, or pesticides at the most effective time of day or night. 

“We know from lab experiments that watering plants or applying pesticides can be more effective at certain times of day, meaning farmers could use less of these resources. This is a simple win that could save money and contribute to sustainability.”

Professor Webb said that indoor “vertical farming” could also be improved using chronoculture. Using this approach, crops like leafy greens are grown under highly controlled light and temperature conditions that can be very energy intensive. By genetically modifying the plants’ circadian clock, the most efficient lighting and heating cycles could be identified. 

“In vertical farming, chronoculture could give total control over the crop,” explained Professor Webb. “We could breed specific crop plants with internal clocks suited to growing indoors, and optimize the light and temperature cycles for them.”

According to Professor Webb, there are many opportunities for chronoculture to make food production more sustainable. The specifics would be different for every location and crop, and more research is needed. 

The study is published in the journal Science.

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By Chrissy Sexton, Earth.com Staff Writer