Can a plant remember?
This may sound more like a line from a poem than a scientific enquiry.
But new analysis suggests that plants can pass on climate adaptation tips to their offspring.
From devastating floods to rising temperatures, the climate crisis is changing natural habitats all over the world.
To survive, many plants have been forced to quickly adapt, new research published in the Trends in Plant Science journal indicates.
They then transmit these new traits on to their offspring, says Federico Martinelli, a plant geneticist at the University of Florence.
“One day I thought [about] how the living style and experience of a person can affect his or her gametes [reproductive cells] transmitting molecular marks of their life into their children,” he explains.
“Immediately I thought that even more epigenetic marks must be transmitted in plants, being that plants are sessile [fixed in one place] organisms that are subjected to many more environmental stresses than animals during their life.”
How do plants adapt to climate change and remember these adaptations?
Changes in the environment forces animals to change, altering their hunting and hibernation patterns and moving habitats.
Plants are rooted to the spot - but they change, too.
For example, winters - which plants use to orient their flowering time - have become warmer and shorter in many regions.
“Many plants require a minimum period of cold in order to set up their environmental clock to define their flowering time,” says Martinelli.
“As cold seasons shorten, plants have adapted to require less period of cold to delay flowering. These mechanisms allow plants to avoid flowering in periods where they have less chances to reproduce.”
Plants don’t make memories in the same way that humans do, but they nonetheless remember. Rather than storing memories in brains (neural networks), they store them in sophisticated cellular and molecular signalling networks.
Researchers call this a ‘somatic memory’, stored in the plant’s body.
“These mechanisms allow plants to recognise the occurrence of a previous environmental condition and to react more promptly in the presence of the same consequential condition,” says Martinelli.
For example, a plant can remember to delay flowering when warmer.
It will pass this trait down to its offspring through something researchers call ‘epigenetics.’
Unlike genetic changes, epigenetic changes do not change a DNA sequence. Instead, they can change how an organism reads a DNA sequence.
“Epigenetic modifications are inherited… thereby contributing to the long-term adaptation of plant species to climate change,” the paper’s authors write.
The research will help scientists understand how plant intelligence is battling climate change.