Jane J. Lee writes at National Geographic:
A study published online today in the journal Current Biology found that store-bought cabbage, lettuce, spinach, zucchini, sweet potatoes, carrots, and blueberries respond to light-dark cycles up to about a week after harvest.
And when the produce was kept on the same light-dark cycle as a predator—cabbage looper moth caterpillars (Trichoplusia ni)—it was better able to resist attacks.
Circadian clocks tell plants when the seasons change due to variations in day length, saidJanet Braam, a plant biologist at Rice University in Houston, Texas. But the clock is also critical in plant defenses against insects.
“[Plants] know when the insects eat,” said Braam, who is a co-author on the recent study, “so they can prepare a defense in advance.”
Braam and colleagues knew that levels of protective compounds called glucosinolates were under the control of the circadian clock in a plant called Arabidopsis.