Plant “clock” a key to growing more food
The Food and Agriculture Organisation of the United Nations has named 2021 the International Year of Fruits and Vegetables, highlighting the need for innovative technologies and new approaches that can improve healthy, sustainable food production and ensure global food security. Now one University of Melbourne-led study has heeded the call, making an important discovery that could help boost the global food supply by leveraging the growing of crops in different environments, including different seasons, different latitudes or even in artificial environments like vertical gardens.
The study has established how plants use their metabolism to “tell time” and know when to grow – revealing how plants use their metabolism to sense time at dusk and help to conserve the energy they produced from sunlight during the day.
Lead researcher Dr Mike Haydon says plants don’t sleep as humans do; their metabolism is adjusted during the night to conserve energy for the big day ahead of making their own food using energy from sunlight, a process known as photosynthesis.
“Getting the timing of this daily cycle of metabolism right is really important, because getting it wrong is detrimental to growth and survival,” Dr Haydon says. “Plants can’t stumble to the fridge in the middle of the night if they get hungry; they have to predict the length of the night so there’s enough energy to last until sunrise – a bit like an alarm clock.”
Dr Haydon and collaborators had earlier shown that the accumulation of sugars produced from photosynthesis gives the plant important information about the amount of sugar generated in the morning, sending signals to its circadian clock to adjust its pace.
“We’ve now found that a different metabolic signal, called superoxide, acts at dusk and changes the activity of circadian clock genes in the evening,” Dr Haydon explains. “We also found that this signal affects plant growth. We think this signal could be providing information to the plant about metabolic activity as the sun sets.”
Researchers hope the study will help the world produce more food in a more reliable way.
“As we strive to produce more food for an increasing global population in the face of a changing climate, we may need to grow crops in different environments,” Dr Haydon says. “Understanding how plants optimise rhythms of metabolism could be useful to allow us to fine-tune their circadian clocks to suit these conditions and maximise future yields.”